D. M. W. Andemon, T. B. Pierce, J. F. Stoddart, and J. D. Wilson(D.M.W.A. : Department of Chemistry, The Univergty, Edinburgh 9; T.B.P. and J. D. W. :Analytical Sciences Division, A.E.R.E., HarweU; J. F. S . : Department of Chemistry,&men's University, Kingston, Ontarw)1. Introduction.-The analytical avalanche has continued, and at an in-creased rate. Since the space allocated to this Report remained constant, thePapers cited have been selected even more critically than before. At thelevel of selectivity required (approx. 5% of the analytical papers published)personal bias must be reflected to some extent. Nevertheless the Reporters,to comply with their terms of reference, have attempted to produce abalanced account of the most significant changes and advances, with theReport intended to be of broad general interest rather than a specialistarticle for analytical chemists.Belcher 1 has given an appraisal of important recent developments, andthe Review Issue of Analytical Chemistry (April 1966) conveys adequately thepresent intense level of activity over the broad range of techniques used inanalytical chemistry today.The pattern of change followed that of recent years.Interest in somefields (e.g. , distillation processes ; qualitative and gravimetric analysis) hasdecreased; in others (e.g., electrophoresis ; solvent extraction; ion exchange ;spectrophotometric methods) a steady state appears to have been reached;in yet others (e.g., organic elementpal and functional group analysis; titri-metry; chromatography) the previous levels of activity have been sus-tained, with the activity centred around novel approaches to previousproblems.In the areas of increased activity, two trends could be distinguished.Inthe first, some new development led to a revival or extension of previouainterest, e.g., plasma sources (spectroscopy), lasers (Raman spectroscopy),probe methods (X-ray), computer techniques (spectroscopy generally).In the second, newer techniques have expanded rapidly (e.g., catalyticanalytical reactions ; molecular-sieve chromatography; atomic absorption,n.m.r., e.s.r., and Mossbauer spectroscopy) either broadening the basis ofanalytical chemistry, or producing some advantage (sensitivity, speed, orselectivity) over the methods existing previously.There have been further features.Conversion of older methods to auto-mated procedures has accelerated ; the use of infrared and mass spectroscopyt19 ancillaries to g.1.c. has increased. In such advances, the chemical contri-butions of the research and development staffs of commercial instrumentcompanies have been striking.2. Qualitative Anslysis.-For the third successive year, Chalmers andco-workers have contributed a novel introduction for this section; theR. Belcher, Chim. analyt., 1966, 4.8, 375.a A. G. Fogg, W. Moser, and R. A. Chrtlmers, Analyt. Chim. Actcr, 1966,88, 248658 ANALYTICAL CHEMISTRYBoedecker reaction (nitroprusside + zinc ions) for sulphite has been mademore sensitive by adding alkali metal ions and pyridine.A structure forthe resulting complex is suggested. Peigl has developed new tests forhydrogen cyanide and cyan~gen,~ and for arsenic(m) sulphide and mercury(=)~yanide.~ A method for detecting nanogram amounts of fluoride ion hasbeen described.Weisz has reviewed the applications of his ring-oven, which continues toform the basis 7 for rapid and sensitive separations of inorganic species.Methods based on solvent extraction into five groups prior to separation bycircular elution thin-layer chromatography were described 8 for the identi-fication of 40 cations and 19 anions from 0.5 ml. of solution. Other inorganicPapers dealt with tervalent lanthanides and actinides,Q and with the separa-tion of alkaline-earth metals as the 2-thenoyltrifluoroacetone complexes byreversed-phase chromatography.1° There were few organic 11 applications,although two interesting Papers described the catalytic use of ion-exchangeresins for detecting esters l a and amides, imides, and anilides.133.Quantitative Organic AnliIysis,-EkmentaZ. Ma and Gutterson l4have published a Review covering the period October 1963-September 1965(359 references). VeEeFa 15 has studied some basic reactions in elementalanalysis ; Malissa and co-workers 16 have discussed recent results in relativeconductometric elemental microanalysis. Indium capsules have beenrecommended 17 for handling volatile, unstable, or hygroscopic materials incarbon-hydrogen analyses, and Kirsten 18 has published a detailed study ofweighing errors with hygroscopic or volatile compounds on the submilligramscale.For the microdetermination of sulphur, Debal and Levy l9 comparedfour methods of mineralisation ; they concluded that reductive reaction withpotassium in a sealed tube, followed by iodometric titration, was the mostreliable of the possible combinations.The Schoniger oxygen-flask technique continued to attract attention.The limitations in determining halogens were discussed;20 other Papersa F. Feigl and V. Anger, Analyat, 1966, 91, 282.‘3’. Feigl, A. Caldas, and L. Bendor, Chemist-Analyst, 1966, 55, 73.’ G. Ackerman and K. Gressman, Mikrochim. Acta, 1966, 4 ; S . D. Bijwas, I(. N.Munshi, and A. K. Dey, Chim. analyt., 1966, 48, 203; L. J. Ottendorfer, Y. A. Gawar-gious, and S.S. M. Hassan, Talanta, 1966, 13, 625.34. M. Hashmi, M. A. Shahid, A. A. Ayaz, F. R. Chughtai, N. Hassan, and A. S.Adil, Analyt. Chem., 1966, 38, 1554.A. D. Wilson and J. R. Cooke, AnaZyst, 1966,91,135.H. Weisz, Fortschr. chem. l?wsch., 1966, 5, 491.@ J. Sta+y, TaZanta, 1966, 13, 421.lo I. Azaka, Bull. Chem. SOC. Japan, 1966, 39, 980.l1 J. GaspariE, Mikrochirn. Acta, 1966, 288.l2 M. Qureshi and S. Z. Qureshi, Analyt. Chim. Acta, 1966, 34, 108.la P. W. West, M. Qureshi, and S. 2. Qureshi, ArulZyt. Chim. Acta, 1966, 36,T. S. MR and M. Gutterson, AnaZyt. Chem., 1966, 38(5), 186R.l6 M. VeEefa, Microchem. J., 1966, 10, 260.lS E. Pell, L. Machherndl, and H. Malissa, Microchem. J., 1966, 10, 286.G. E. Secor and I;. M. White, Analyt. Chem., 1966, 38,945.l8 W.J. Kirsten, Milcrochim. Actu, 1966, 105.l* E. Debal and R. Levy, Jlikrochim. Acta, 1966, 202.ao Kh. Ya. Kuus and 1;. A. Lipp, Zhur. analit. Khim., 1966, 21, 1103.97ANDERSON, PIERCE, STODDART, AND WILSON 659discussed the determination of halogens,21 halogens and sulphur,22 sulphur, 23selenium,2* and carbon.25There were many Papers on the determination of oxygen.26 The diffi-culties caused by the presence of sulphur were studied,27 and it is claimedthat a g.1.c. method of determining the carbon monoxide evolved is particu-larly suitable for determining traces of oxygen.Eulenhofer 29 determined the total nitrogen in ammonium, nitrate, andurea compounds in one operation; Hozumi 30 used a sealed-tube combustionfor nitrogen determinations on the decimilligram scale, and Yeh 31 gave arapid micro-Dumas method.A single perchloric acid digestion 32 facilitatesrapid determinations of traces of nitrogen (by Nesslerisation) and phos-phorus (by Molybdenum Blue) in natural products, and compounds con-taining tertiary nitrogen. Improved combustion techniques a3 for micro-determinations by automatic analyser were also described.As is usual in this section, however, the greatest activity centred rounddeterminations of carbon, hydrogen, and nitrogen. Automatic micro-analysers have been de~cribed.3~ For carbon and hydrogen analyses, a rapidsubmicro-analyser has been developed,35 and Thomas 36 has given details ofa relatively inexpensive, easily constructed apparatus : other useful contri-butions were given by Hadzija 37 and Salzer.s8Darge 3Q has reviewed the modern methods for the microanalysis ofcarbon, hydrogen, and nitrogen, and an automatic method has beendescribed.40 Kainz and Chromy have studied the decrease in oxidisingefficiency of oxide la~ers,~1 and have also investigated the causes of errorthat arise in boron-containing compound^.^^ Russian workers 43 proposed a21 M.E. Fernandopulle and A. M. G. Macdonald, Mkrochem. J., 1966, 11, 41; J.HorbEek and V. Pechanic, Mikrochim. Acta, 1966, 17; W. I. Awad, Y. A. Gawaxgioua,S. S. M. Hassan, and N. E. Milad, Analyt. Chim. Acta., 1966, 36, 339.a* R. McGillivray and S. C. Woodger, Analyst, 1966,91,611; S. Otta, Japan A?tdyst,1966, 15, 689.2a G. Gorbach and E.Regula, Mikrochim. Acta, 1966,615; A. R. Johnson and G. B.McVicker, Analyt. Chem., 1966, 38, 913.24 Kh. Ya. Kuus and L. A. Lipp, Zhzcr. anulit. Khim., 1966, 21, 1266.26 R. Belcher and G. Ingram, Microchem. J., 1966,11,360; G. Kainz and F. Scheidl,Mikrochim. Acta, 1966, 624; E. Pella, Analyt. Chim. Acta, 1966, 35, 96; M. Vecera andJ. Lakomy, Mikrochim. Acta, 1966, 370.a7 L. Haraldson, Mikrochim. Acta, 1966, 1068.28 C. Pippel and S. Romer, Mikrochim. Acta, 1966, 1039.2s H. G. Eulenhijfer, 2. analyt. Chem., 1966, 215, 31.5o K. Hozumi, Analyt. Chem., 1966, 38, 641.a1 C. S. Yeh, Microchem. J., 1966, 11, 229.aa D. S. Galanos and V. M. Kapoulas, Analyt. China. Acta, 1966, 34, 360.aa M. L. Tefft and G. M. Gustin, Microchem. J., 1966, 10, 175.84 R.D. Condon, Microchem. J., 1966, 10, 408; A. N. Prezioso, ibid., p. 616.ss C. D. MilIer, Mkrochem. J., 1966, 11, 366. *( A. C. Thomas, Mikrochim. Acta, 1966, 1000.a7 0. Hadzija, Mikrochim. Acta, 1966, 951.38 F. Salzer, Microchem. J., 1966, 10, 27.as K. Darge, Chem.-Ztg., 1966, 90, 283. '* L. Foissac, Chim. analyt., 1966, 48, 354. '* G. Kainz and G. Chromy, 2. analyt. Chem., 1966,218,104.oa G. Kainz and G. Chromy, Mikrochim. Acta, 1966, 1140.4a N. M. Chwnanchenko and I. E. Pakhomova, Doklady Akad, NaukS.S.S.R., 1966,G. Gutbier and W. Ihn, Mikrochim. Acta, 1966, 24.170, 125660 ANALYTICAL CHEMISTBYnew method involving g.l.c., and additional techniques for the submicro-range were proposed.44 Other important Papers described the ~rnultaneousmicrodefermination of carbon, hydrogen, and sulphur,45 and a rapid double-tube automatic apparatus for carbon, hydrogen, oxygen, and nitrogenanalyses .P6There have been several studies 47 of the determination of carbon dioxide,upon which many elemental analyses depend.EsunctionaE Groups.Fredericks and Taylor 48 have published a generalmethod for identifying functional groups in mixtures of acids, alcohols,aldehydes, esters, and ketones ; the sample is treated with classificationreagents in a micro-syringe, then injected directly into a gas chromatograph.Similar gas-volumetric approaches 49 involving chemistry in capillaries 5Owere described, and thermometric titration 51 was used for functional-groupanalysis.An interesting development in alkoxyl determinations has arisen from therecognition 52 that some substances yield low results because of " resonancestabilisation " ; compounds have been synthesised for comparative studies 53of the stability of the ether linkage.Crompton 64 has described an iodimetricprocedure for determining dialkylaluminium alkoxides, which cannot bedetermined by isoquinoline titration. Schachter and Ma 55 have appliedg.1.c. to analyses of alkoxyl and alkimino-groups, and there has been a studyof the micro-determination of the thioalkylTwo interesting methods for determining ester groups have been pub-lished. Clancy and Kramm 57 treated orthoesters with a known excess ofwater in a trichloroacetic acid-methanol system, followed by determinationof the surplus water by Karl Fischer titrimetry.Vinson and co-workers 5 8utilised the unusually rapid rate of hydrolysis of esters in aqueous dimethylsulphoxide.The effect of water on the determination of acetyl groups has been in-ve~tigated,~~ and g.1.c. has been used 6O to determine the liberated aceticacid after solvent extraction with butyl ethyl ether.44 W. Wdisch, 0. Scheurbrandt, and W. Marks, Microchem. J., 1966,11, 315.45 R. C. Rittner and R. Culmo, Microchem. J., 1966,11, 269.46 I. Monar, Mikrochim. Acta, 1966, 934.47 P. Braid, J. A. Hunter, W. H. S. Massie, J. D. Nicholson, and €3. E. Pearce,Analyst, 1966, 91, 439; K. Beyerman and E. Knoll, 2. ma@?. Chem., 1966, 219, 13;Y. Pribyl, ibid., 1966,217, 7; D. C. White, Talanta, 1966,13, 1303; V.Zdenek and V.Skorepa, Chem. Zisty, 1966, 60, 1391.48 K. M. Fredricks and R. Taylor, AnaZyt. Chem., 1966, 38, 1961.49 T. N. Tischer, A. D. Baitsholts, and E. P. Pnybylowicz, AnaZyt. Chirn. Acta, 1966,34, 101; D. F. Hagen, J. L. Hoyt, and W. D. Leslie, AmZyyt. Chem., 1966, $8, 1691.61 D. E. Mom, Db8. Abs., 1966, 26, 6998.5 * A. Pietrogrmde, F. Bordin, and G. D. Fin& Mikmhirn. Acta, 1966, 1166.53 A. Wacek and H. Hemetsberger, Momtsh., 1966,97, 744.64 T. R. Crompton, Analyst, 1966, 91, 374.66 M. M. Schachter and T. S. Ma, Mikrochim. Actla, 1966, 56.S S V . A. Klimova, K. S. Zebrodha, and N. L. Shitikova, Izveat. AEd. Nauk6 7 D. J. Clancy and D. E. Kramm, Talanta, 1966,13, 631.68 J. A. Vinson, J. S. Fritz, and C. A. Kingsbury, Talantu, 1966,18, 1673.69 W.H. Grieve, K. F. Sporek, and M. K. Stinson, AnaZyt. Chem., 1966,88, 1264.6o D. N. Ward, J. A. Coffey, D. B. Ray, and W. M. Lamkin, Anulyt. Biochem., 1966,J. S . Wiberley, Microchem. J., 1966, 11, 343.S.S.S.R., Ser. khim., 1966, 1850.14, 243ANDERSON, PIERCE, STODDART, AND WILSON 661To determine primary and secondary hydroxyl groups, xenon trioxidecan be used;61 reaction with succinic anhydride has been revived,62 andesterification methods involving acetylation, anhydrides, and acid chlorideshave been reviewed.63 For acetylations, 2,4-dinitrobenzenesulphonic acidhas been recommended 64 as a catalyst, and 1,2-dichloroethane was found 65to be a better solvent than ethyl acetate for reactions catalysed by perchlorkacid.Fleet 66 determined carbonyl groups polarographically as the mmicar-bazones ; other investigators studied the reactions of carbonyl groups withhydrazine 61 and phenylhydrazine.6*Other Papers have discussed the determination of carboxyl groups incellulose, 69 the determination of acid anhydrides and amides, ' 0 diazo-gr~ups,~lperoxides and hydroperoxides.72The determination of active hydrogen' by reaction with carbodi-imide~~~and by a chromatographic method 75 has been described.N-Active hydrogencan be detected 76 by a t.1.c. method, and the possibility of making quanti-tative determinations was discussed briefly.There have been several studies of sulphur functions. Belcher, Gawar-gious, and Macdonald 77 described a bromination method €or sulphide anddisulphide groups on the submicro-scale; Veibel and Wronski 78 deter-mined disulphides mercurimetrically after reaction with butyl-lithium.Disulphide groups in proteins were determined 7@ with sodium borohydride in8~-urea, as reducing agent, and 5,5'-dithiobis-( 2-nitrobenzoic acid) as a thiolsulphide exchanger.Allenmark 8o studied the quantitative determination ofsulphoxides.4. Electrochemical Methods.-The majority of Papers on electrochemicalmethods of analysis described polarographic methods. This preponderancearose because many papers on voltammetry were devoted only to electrodereaction kinetics; the effect would have been even more marked but for asustained interest in anodic stripping voltammetry. Controlled-potential61 B.Jaselskis and J. P. Waminer, Analyt. Chem., 1966, 38, 563.62 C. K. Narang and N. K. Mathur, Indian J . Chem., 1966,4, 263.65 N. K. Mathur, TaZanta, 1966,13, 1601.6 4 D. J. Pietrzyk and J. Belisle, Analyt. Chem., 1966, 38, 1508.J. A. Magnusson and R. J. Cerri, Analyt. Chem., 1966, 38, 1088.66 B. Fleet, Analyt. Chim. Acta, 1966, 36, 304.67 I. Gunne and 0. Samuelson, Svensk Papperstidn., 1966, 69, 391.68 Z. Nowak, Chem. Analit., 1966, 11, 753.69 K. Wilson, Svensk Papperstidn., 1966, 69, 386.7 0 R. D. Tiwari, J. P. Sarpal, and I. C. Shukla, Indian J . Chem., 1966, 4, 221.71 P. Kozak, I. Slamova, and M. Jurecek, Mihochim. Acta, 1966, 1024.72 A. P. Terent'ev, 0. G. Larikova, and E. A. Bondarevskaya, Zhur. a d & Khim.,73 I. Shroder, U. Schneider, and R.Schnorr, 2. Chem., 1966, 6, 70.7 4 A. Stephen, Monatsh., 1966, 97, 695.75 M. M. Chumachenko, L. B. Tverdyukova, and F. 0. Leenson, Zhw. andit. Khim.,76 M. R. F. Ashworth and G. Bohnstedt, Takanta, 1966, 13, 1631.77 R. Belcher, Y. Gawargious, and A. M. G. Macdonald, Mikrochim. Acta, 1966.78 S . Veibel and W. Wronski, AnaEyt. Chem., 1966, 38, 910.Tg D. Cavallini, M. T. Graziani, and S. Dupr6, Nature, 1966, 212, 294.1966, 21, 355.1966, 21, 617.114.S. Allenmark, Acta Chm. Scund., 1966, 20, 910662 ANALYTICAL CHEMISTRYcoulometry and chronopotentiometry made only slight contributions to thetotal.Polarography. One issue of Tahnta 81 was devoted entirely to Reviewsof various aspects including the polarography of proteins, polyanions,oxyanions in molten salts, and cations in organic solvents. Rooney hasreviewed the use of modern polarographs in analysis,s2 with some emphasison cathode-ray polarographs, and has drawn attention to the fact that sometrace impurities in solution can affect the e.m.f.of the mercury pool anodesoffen used, and cause difficulty in matching the cathode potentials in differ-ential instruments.8S The ability of the differential cathode-ray polarographto subtract unwanted blanks has been used to measure copper, lead, cadmium,zinc, nickel, cobalt, iron, manganese, and uranium at the 1 p.p.m. level or lessin high-purity beryllium, after an initial chemical separation. * 4 The pulsepolarograph has been used to measure aromatic nitro-compounds 85 at con-centrations of to ~O-*M, the uranyl ion 86 (as its arsenazo-complex) a t4 x lo-%, and traces of bismuth, copper, and lead in cadmium.87Many Papers have appeared on the improvement of the sensitivity, rangeof application, and selectivity of d.c.polarographic methods. The catalyticwave produced by tungsten in 8, base electrolyte of @6~-tartaric acid and9M-perchloric acid has been recommended 88 for measurements in the range5 x 10-7 to 1 0 - 4 ~ . Methods have been given for the measurement ofnitrohydro~ylamine,8~ and the azide ion 90 in the presence of other nitrogencompounds; the waves produced by the reduced form of silicomolybdic acidhave been used to measure silica, or molybdenum in the 0.1 to 100 and 5 to5000 p.p.m. ranges respe~tively.~~ The convenience of making measure-ments directly on an organic phase after solvent extraction has led to theinvestigation of the polarography of a number of metal-pyridine-thiocyanatecomplexes in toluene,92 whilst measurements in a solution of tri-n-octyl-phosphine oxide in cyclohexane have enabled uranium concentrations of4 x 10-SM (in the aqueous phase before extraction) to be dete~mined.~sThe use of the dropping-gallium electrode in a fused lithium nitratepotas-sium nitrate mixture has been in~estigated.~~ It has been shown that wavessuitable for the measurement of arsenic(v) or titanium(m) can be obtained ina base electrolyte of ZM-perchloric acid and 0.5 to l~-pyrogallol,~~ whilst abase electrolyte of 0-5~1-citric acid, O-O25~-sulphu~c acid, and 0.05~-Tahnta, 1965,12, 1065.82 R.C. Rooney, Chern. and Id., 1966, 875.8a R. C. Rooney, J . Polarog. SOC., 1966, 12, 35.84 G. C. Goode, J. Herrington, and J. K. Bundy, Analyst, 1966, 91, 719.85 G. Wolff and H. W. Niirnberg, 2. analpt. Chem., 1966,216, 169.86 Y. Chapron, E. Graziani, and H. Francois, Compt. rend., 1966,262, C, 1247.87 E. Temmerman and F. Verback, J . Electroanalyt. Chem., 1966, 12, 168.88 R. Bock and B. Bockholt, 2. analyt. Chem., 1966, 216, 21.89 A. Calusaru, J . Electroandyt. Chern., 1966, 12, 341.R. Schrader and G. Pretzschner, Tuhnta, 1966,13, 1105.@1 P. Sen and S. N. Chatterjee, Analyt. Chem., 19G6, 38, 636.02 B. F. Afghan and R. M. Dagnall, Talanta, 1966,15, 1097.08 W. I,. Belew, D. J. Fisher, M. T. Kelley, and J.A. Dean, Microchem. J., 1966,94 R. B. Escue, T. H. Tidwell, and D. K. Dickie, J . Electroanalyt. Chm., 1966, la,9s M. C. White and A. J. Bard, Analyt. Chem., 1966, 88, 61.10, 301.220ANDERSON, PIERCE, STODDART, AND WILSON 663thorium(Iv) was used for molybdenum and titanium in niobium, tungshn,and tantalum-based alloys;Q6 niobium could be measured if titanium wasabsent.Electrochemical masking continues to be studied Q7 and methods havebeen given for measuring bismuth and antimony in the presence of tin, andthallium in the presence of cadmium and indium.98 The procedure has beenreversed for the determination of surface-active compounds ; thus organo-phosphorus compounds have been measured using the depression of the waveof a copper-EDTA complex>B and pilocarpine (in eyeball fluid) using theshift of the oxygen wave.lW An attempt to use matrix algebra to resolve thecomplex wave produced by species with poorly separated half-wave potentialawas reasonably successful for binary, but less so for ternary, mixtures of o-,m-, and p-nitrobenzoic acids (range of half-wave potentiels--80 mv).lol Itis in the separation of such compounds that chromatopolarography has so farfound its major use.lo2 Conventional measurements of organic compounds inmixtures have included those of Z-phenylindane- 1,3-dione (an anticoagulant)in bl00d,lO3 of N-vinylpyrrolidone monomer in the polymer,lo4 and of cate-chol in developer-fixer solutions.105Voltccmmetry and chronopotentimetry.The anodic stripping voltammetryof some elements at solid microelectrodes has been shown to be more sensitiveand convenient if the derivative peak-height is measured instead of the peakarea.lo6 The factors affecting the behaviour of rotating-disc electrodes havebeen evaluated, lo7 and the rotating carbon-epoxy-resin electrode has beenshown to be similar to the pyrolitic graphite electrode.108The voltammetry of many ions a t a rotating platinum electrode inlM-ammonium fluoride has been investigated and it was found that theoxidation of manganese(=) could be used for its measurement in steels andcast irons low in cobalt.log Methionine in very small volumes of hydro-lysates has been measured using a platinum microelectrode.ll0 Anodicstripping voltammetry has been widely used, especially in the determinationof impurities below the 1 p.p.m.level in high-purity materials such asarsenic,lll aluminium, manganese, and gallium .l12 The use of cathodictstripping voltammetry, involving the reduction of insoluble compoundsO6 J. B. Headridge and D. P. Hubbard, Analyt. Chim. Acta, 1960, 85, 85.O 7 T. Fujinaga, K. Izutsu, and T. Inoue, CoU. Czech. Chem. Cmm., 1965,30, 4202.O 8 E. N. Vinogradova, G. V. Prokhorova, L. B. Sveshnikova, and L. A. Sharova,Zhur. analit. Khim., 1966, 21, (359.H. Sohr, J . Electroanalyt. Chem., 1966, 11, 188.loo 0. Hockwin, 2. analyt. Chem., 1966, 216, 255.lol Y. Israel, Talanta, 1966, 13, 1113.loa G. F. Reynolds, J . Polarog. SOC., 1966, 12, 27.lo3 Ya. P. Stradyn, I. K. Tutane, and G.Ya. Vanag, J . Analyt. Chem. (U.S.S.R.),lo4 V. D. Bezuglyi and Yu. P. Ponomarev, Z ~ U T . analit. Khim., 1966, 20, 1231.lo5 L. R. h a k e and Q. F. Reynolds, J . Pohrog. SOC., 1965,11, 68.lo* S. P. Perone and El. E. Stapelfeldt, Analyt. Chem., 1966, 38, 796.lo' K. B. Prater and R. N. Adams, Analyt. Chem., 1966, 38, 163.lo8 H. S. Bwofford, jun., and R. L. Carman, tert., Analyt. Chem., 1966, 88, 960.lo@ A. G. Hamza and J. B. Headridge, Talanta, 1966,13, 1397.ll1 P. Berser, K. Finger, and F. Von Sturm, 2. analyt. Chm., 1966,216, 189.lla J. Lovasi and L. Zombory, MiCrochem. J., 1966, 11, 277.1965,20, 1239.D. Kyriacou, Nature, 1966, 211, 519664 ANALYTICAL CHEMISTRYpreviously precipitated at a solid electrode by oxidation, has been continued ;manganese(@ a t the lo-* to 1 0 - s ~ level has been determined at the platinumelectrode, via the formation of manganese dioxide,1l3 and thaIlium(r) andantimony(m) have been measured using a graphite electrode via thallichydroxide 114 and the antimony(v)-Rhodamine C complex 115 respectively.The limitations of chronopotentiometry as an analytical method have beendi8ct;lssed,ll6 but it has been found to be a convenient way of extending thesensit,ivity of the anodic stripping procedures.l17 A sensitive, selectivegalvanometric method of measuring hydrofluoric acid in gases, or fluorides insolids using electrodes of platinum and very pure silicon has been described.ll8Both dimethyl sulphoxide 119 and hexamethylphosphotriamide l20 have beenstudied as solvents for voltammetry; the working voltage ranges, as well assuitable reference electrodes and base electrolytes, have been given.Voltam-metric measurements of relatively high concentrations of uranium(1v) in amolten mixture of lithium, beryllium, and zirconium fluorides have also beendescribed. 21Apparatus. Now that the use of operational amplifiers is established,more attention is being given to the details of their application. A three-electrode potential control system has been designed to meet the moreexacting demands of the a.c. polarograph,122 whilst the remaining uncom-pensated iR drop in the cell, arising from practical difficultiesinpositioning thereference electrode, has been reduced by repositioning the counter electrode,123or by using a manually adjusted positive feedback loop in the control cir-cuit.124 The printing-out of data in a digital form, and the use of multi-channel pulse-height analysers as data buffer stores, have been described.1255.Radiochemistry.-This section is divided into two parts; the first isconcerned with the analytical applications of pre-irradiated radioisotopes,but excludes reference to tracer techniques widely used to evaluate theefficiency of an analytical procedure or to develop separation schemes ; thesecond is concerned with activation analysis and related nuclear techniques,in which the irradiation of the sample is an integral part of the analyticalprocedure. A Review of both types of method covering the period October1963-October 1965 has been published.126Substoicheiometric finishes have been proposed forthe determination of zinc 127 and rare earths, specifically holmium andIsotope techniques.113 C.0. Huber and L. Lemmert, Analyt. Chem., 1966, 38, 128.114 Kh. Z. Brainina and N. K. Kiva, J . Analyt. Chern. (U.S.S.R.), 1965, 20, 1306.115 Kh. Z. Brainina and E. Ya. Sapozhnikova, Zhur. analit. Khim., 1966, 21, 807.116 J. J. Lingans, Analyst, 1966, 91, 1.117 W. Kemula and J. W. Strojek, J. Electroanalyt. Chem., 1966, 12, I.11* A. Berton, Compt. rend., 1966, 262, C , 904.119 J. Courtot-Coupez and M. le Demezet, Compt. rend., 1966, 203, C , 997.120 J.-E. Dubois, P.-C. Lacaze, and A. M. de Ficquelmont, Compt. rend., 1966, 262,131 G. Mamantov and D. 1;. Manning, Analyt.Chem., 1966, 38, 1495.122 M. E. Peover and J. S. Powell, J. Polarog. SOC., 1966, 12, 64.133 T. Damokos and E. Juhasz, Talanta, 1966, 13, 559.124 E. R. Brown, T. G. McCord, D. E. Smith, and D. D. Deford, Analyt. Chem., 1966,125 E. R. Brown, D. E. Smith, and D. D. Deford, Analyt. Chem., 1966, 38, 1131.1z6 W. S. Lyon, E. Ricci, and H. H. ROSS, Analyt. Chem., 1966, 38, 251R.1%' C. Ballaux, R. Dams, and J. Hoste, Analyt. Chim. Acta, 1966, 35, 141.c, 181.88, 1119ANDERSON, PIERCE, STODDART, AND WILSON 665thulium,12s by isotope dilution. The zinc was extracted with a standadsolution of Dithizone before measurement, and the rare earths, after additionof a substoicheiometric quantity of EDTA, were passed down a cation-exchange column to separate the complexed from the uncomplexed ele-ments.Back-titration with EDTA has been used for the rapid radiometricdetermination of several elements employing ll~AgIOs as indi~at0r.l~~Radiometric methods have also been used in quantitative paper chromato-graphy for the determination of iron, copper, manganese, and cobalt.lS0Precipitation with trisodium phosphate labelled with 32P, adsorption ofWO, or exchange of 59Fe was used to provide a radioactive product whichcould be assayed.An instrument for the determination of dissolved oxygen, suitable foroceanographic use, has been devised, based on radio-release I rin~ip1es.l~~Radioactive thallium is released as thallous ions from a column of thalliummetal according to the equation4TI(s) + O,(aq) + ZH,O(liq) -3 4Tl+(aq) + 40H-(aq)Exchange of 1311, initially in a benzene phase, with iodide ions in aqueoussolution has been used to determine iodide in natural waters.132 Thesensitivity of the method was better than 1 pg.but depended upon thespecific activity of the 1311 and the purity of the reagents.The addition of a carbon-14 labelled quaternary ammonium halide([ 1-l4C]hexadecyl trimethylammonium bromide) has permitted the surfacearea and roughness of a variety of samples to be assayed.l33 The methodhas been applied to both planar and powdered materials.Many Papers have appeared on the subject of liquid scintillation counting.Errors in the measurement of tritium by liquid scintillation counting ofemulsions have been considered,134 and a computer programme has beendevised for the simultaneous measurement of the radioactivity of quenchedsamples containing two different /3-emitting isotopes.l35 For some samplesCerenkov counting of liquid samples may be more convenient than liquidscintillation counting, although the efficiency is likely to be lower.136Radioactive gases have been counted after being trapped in a scintillatorsolution;137 counting should be carried out soon after preparation of thesolutions because of slow escape of gas from the scintillator. When com-bustion of a sample before counting is necessary, “ i n vial’’ combustiontriggered by a focused light beam 138 has been employed, and a combinationof the oxygen flask and sealed-tube methods has been pr0posed.1~~Activation analysis. During the year many Papers have been published12* J.PCaZolivh, Tulunta, 1966, 13, 1567.12# K. Muller, Analyt. Chim. Rcta, 1966, 35, 162.13* A. R. Landgrebe, T. E. Gills, and J. R. DeVoe, Analyt. Chem., 1966,38,1265.131 A. S. Gillespie and K. F. Roberts, T~uizs. Amer. Nucl. SOC., 1966, 9, 695.132 If. G. Richter, AnuZyt. Chem., 1966, 38, 772.133 J. Kivel, Trans. Amer. Nucl. Soc., 1966, 9, 593.13* R. H. Benson, Analyt. Chem., 1966, 38, 1353.lS6 R. Ninomiya, Internat. J. Appl. Radiation Ieotopes, 1966, 17, 355.136 R. P. Parker and R. H. Elrick, Internat. J . Appl. Radiation Isotopes, 1966,17,361.13T M. L. Curtis, S . L. Ness, and L. L. Bentz, Arullyt. Chem., 1966, SS, 636.13* G. N. Gupta, Analyt. Chem., 1966, 38, 1356.lSe B.F. Scott and J. R. Kennally, AnuZyt. Chem., 1966, 88, 1404666 ANALYTICAL CHEMISTRYon activation analysis and related nuclear techniques, but reactor activationof samples is still most commonly employed. More than 70 Papers con-cerned with a variety of aspects of activation analysis have appeared in theproceedings of an International Conference.14* Reactor neutron activationhas been extensively used for the determination of major, minor, and traceelement compositions of a very wide variety of samples, with or withoutchemical separation of the isotope to be assayed from all other active con-stituents of the samples. Activation analysis has been compared with massspectroscopy and stable-isotope dilution,141 and a comparison of resultsobtained by computer reduction of y-spectra and by carrier separation ofdopants in silicon has also been ~ub1ished.l~~ An interference coefficient hasbeen proposed for characterising side-reactions, 143 and a modified method ofcalculating self-shielding factors has been ~uggested.1~~ Substoicheiometricfinishes have been used in chemical procedures for the determination ofgallium 145 and manganese,146 and a standard addition technique has beenemployed to permit calculation of chemical yield 147 when suitable carriersare not available.The majority of activation procedures, particularly for trace-elementdeterminations, employ radiochemical separations but improvements ininstrumentation and methods of data processing make instrumental activa-tion increasingly more attractive.The high resolution of germanium counters has been employed withadvantage for the determination of the elements in ores and in the in-vestigation of 15th Century documents.14Q Coincidence techniques mayyield simpler and more easily interpreted y-spectra provided the decayingnuclide has suitable decay characteristics and the lower efficiency of thecounting system can be tolerated.y-y-Coincidence spectrometry has beenused to determine chlorine by measuring the cascade y-rays of 38Cl,150 and thesensitivity of fast-sum coincidenie spectrometry for a number of elements hasbeen discussed.151 Multidimensional y-ray spectrometry may also be usedwith advantage in suitable cases.152140 “Modern Trends in Activation Analysis,” Proceedings of the 1965 InternationalConference at College Station, Texas, U.S.A., April 19-22, 1966, Texas A.& M.Wniversity .lol E. Roth, A. Cornu, and P. Albert, 2. analyt. Chem., 1966, 218, 24.lop K. 0. Heinsn and G. Larrabee, Analyt. Chem., 1966, 38, 1853.lpS G. Pfrepper, 2. analyt. Chem., 1966, 217, 99.14p B. T. Kenna and B. H. Van Domelen, Internat. J. Appl. Radiation Ieotopes, 1966,A. Zeman, J. RfiiiEka, and V. Kuvik, Talanta, 1966, 13, 271.lp8 A. Zeman, J. Prasilova, and J. Ri%i&ka, Talanta, 1966, 13, 457.Io7 A. &an and R. Parthasarathy, Analyt. Chim. Acta, 1966, 35, 69.J. F. Lamb, S. G. Prussin, J. A. Harris, and J. N. Hollander, Analyt. Chem., 1966,38, 813.1 u G. L. Schroeder, H. W. Kraner, R. D. Evans, and T.Brydges, Science, 1966,151,815.lSo E. T. Brctmlitt, Analyt. Chem., 1966, 38, 1669.lS1 M. Waldgren, J. Wing, and J. Hine3, “ Modern Trends in Activation Analyeis,”Proceeding3 of the 1965 International Conference at College Station, Texas, U.S.A.,April 19-22, 1965, Texas A. & M. University: p. 134.Modern Trends in Activation Analysb,”Proceedings of the 1965 International Conference at College Station, Texas, U.S.A.,April 19-22, 1965, Texas A. & M. University, p. 48.17, 47.Is* R. W. Perkins and D. E. RobertsonANDERSON, PIERCE, STODDART, AND WILSON 667Processing of data from y-spectrometry by computer is now widelypractised ; data convolution has been recommended to reduce statisticalscatter 163 and the use of linear programming to resolve the composition ofspectra has also been suggested.154 Compositional analysis of multi-elementspectra has been carried out on a desk-type ~a1culator.l~~ Computer tech-niques have been used to determine the minimum detectable content of traceelements in neutron-activated materials,l56 and the sensitivities of over 65elements in six matrices as determined by instrumental activation analysishave been given.lS7Neutron generators continue to be used as a compact source of high-energy neutrons; sealed-tube generators now offer an alternative to the moreconventional drift-tube rna~hine.1~8 Oxygen determinations figure largelyin fast neutron applications, and fast neutron activation analysis has beencompared with hot extraction analysis for oxygen determination^.^^^Portable neutron generators have been used for {n &tu activation of soil andgeological samples; 3 MeV neutrons from the reaction 2H(d,n)3He have beenfound to provide a relatively uniform flux of neutrons of less than lKev to adepth of 19-20 in.l60 A pulsed neutron source has been investigated foranalysing the lunar surface, inelastic scattering and radioactive captureradiation, and y-rays from radioisotopes are distinguished by their time ofemission relative to the neutron pulse.1618He ions of an energy of less than 5.5 Mev can be applied usefully t ocarbon and oxygen determinations if 3He ions of higher energy are notavailable.le2 Titanium and iron have been determined in aluminium bycharged particle activation analysis using the reactions 48Ti(p,n)48~ (ref.163)and 56Fe(p,n)56Co (ref. 164) respectively.y-Photon activation is now regularly applied to the determination oflight elements and the cross-sections from threshold to 65 Mev have beenpublished for the reactions l60 (y,n) 150 (ref. 165) and 12C (y,n) 1% (ref. 166).The use of secondary reactions has been reviewed.167Interest has been renewed in the use of elastic scattering for thelSs H. P. Yule, AnaZyt. Chem., 1966, 38, 103.F. J. Kerrigan, Analyt. Chem., 1966, 38, 1677.J. Op De Beeck and J. Hoste, Analyt. Chim. Acta, 1966, 35, 427.J. Pauly, G. Guzzi, F. Girardi, and A. Borella, Nuelear Iw~T. and Methoda, 1966,42, 15.lS7 H. P. Yule, Analyt. Chem., 1966, 38, 818.168 J. D. L. H. Wood, D. W.Downton, and J. M. Bakes, “ Modern Trends in Activa-tion Analysis,” Proceedings of the 1965 International Conference at College Station,Texas, U.S.A., April 19-22, 1965, Texas A. & M. University, p. 175.lsQ C. Pasztor and D. E. Wood, TaZanla, 1966, 13, 389.F. E. Senftle and A. F. Hoyts, Nuclear Instr. and Methods, 1966, 42, 93.lS1 R. L. Caldwell, W. R. Mills, jun., L. S. Allen, P. R. Bell, and R. L. Heath, Science,lS2 S. Gorodetzky, A. Pape, A. Chevallier, J. C. Sens, and R. Armbruster, Nzccteup.lS3 E. Schweilcert and P. Albert, Compt. rend., 1966, 262, C, 87.le4 E. Scliweikert and P. Albert, Compt. rend., 1966, 262, C, 342.le6 B. C. Cook, J. E. E. Baglin, J. N. Bradford, and J. E. Griffin, Phye. Rev., 1966,DM B. C. Cook, J. E. E. Baglin, J.N. Bradford, and J. E. G r i f , Phys. Rev., 1966,lS7 D. C. Aumann, Atompraxit3, 1966,12, 77.1966,152, 457.Instr. and Methods, 1966, 42, 269.1A3, 712.143,724.668 ANALYTICAL CHEMISTRYexamination of surfaces, particularly for the measurement of thin films ona lighter backing,lss, ls9 and neutron time-of-flight spectroscopy has beenused to determine carbon, nitrogen, and 0xygen.1~0Prompt y-rays emitted as a result of the reaction 1*B(n,a)7Li have beenused to determine boron,171 and prompt y-rays 1 7 2 and or-particles 173emitted during scans of samples with collimated particle beams have beenused to investigate inhomogeneous distributions of light elements.6. Spectroscopic Analysis.--MisceZlaneous techniques. During the yearsome novel spectroscopic methods, from an analytical viewpoint, weredescribed.These included /%ray scattering,17* and magneto-optical rotationspectra.175 Neutron time-of-flight spectroscopy 176 offers a nondestructivemethod for determining carbon, nitrogen, and oxygen by deuteron irradiation,and the stable tracers carbon-13, nitrogen-15, oxygen-17, and oxygen-18 byproton irradiation.The analytical applications of microwave spectroscopy have beenreviewed,177 and a Zeeman-modulated microwave spectrometer 178 for thestudy of free radicals has been described.Emission spectroscopy. Margoshes and Scribner 179 have given a Review(351 references) covering the period 1964-1965, and Scribner l8O has con-sidered the recent advances in excitation sources. The helium-neon gaslaser gives 181 intense monochromatic radiation which is almost non-diver-gent, and has advantages where spark excitation is difficult because of un-desirable discharge modes and diffuse discharges.ls2 There have beenseveral theoretical Papers and calculations of the " limit of detection " inquantitative spectrographic analysis,l83 and the possibility of a truly absolutemethod of spectrographic analysis, in which the concentration of an elementcould be determined without the prior construction of a calibration curve,has been considered.184 Malissa lS5 has suggested that " stereometric "analysis should be introduced in metallographic procedures, since homo-geneity of spatial position must be established in complex materials as well ashomogeneity of chemical comppsition.Riemann 186 has described a pneumatic aerosol generator for spectro-168 M.Peisach and D. 0. Poole, Analyt. Chem., 1966, 38, 1345.160 0. U. Anders, Analyt. Chem., 1966, 38, 1442.170 M. Peisach, Chem. Comrn., 1966, 632.171 T. L. Isenhour and G. H. Morrison, Analyt. Chem., 1966,38, 167.1 7 2 T. B. Pierce, P. F. Peck, and D. R. A. Cuff, Natzcre, 1966, 211, 66.173 B. K. Mak, J. R. Bird, and T. M. Sabine, Nature, 1966, 211, 738.174 R. Jirkovsky, Mikrochim. Acta, 1966, 186.175 €3. Briat, M. Billardon, J. Badoz, and J. Loriers, Analyt. Chim. Acta, 1966,34,466.177 D. R. Lide, Advances Analyt. Chem. Instrumera., 1966, 5 , 235.178 J. M. Goodings and T. M. Sugden, J . Sci. Instr., 1966, 43, 692.1 7 9 M. Margoshes and B.F. Scribner, Analyt. Chem., 1966, 38(5), 297R.181 M. J. Houle and K. Grossaint, Artalyt. Chem., 1966, 88, 768.M. Peisach, Chem. Comm., 1966, 632.B. F. Scribner, Pure Appl. Chem., 1966, 10, 579.A. Felske, W. D. Hagenah, and K. Laqua, 2. unalyt. Chem., 1966, 216, 50.P. W. J. M. Boumans and F. J. M. J. Maessen, 2. anulyt. Chem., 1966, 220, 241;G. Ehrlich and R. Gerbatsch, ibid., p. 260; D. J. Hobbs and D. M. Smith, C a d .Spectroscopy, 1966, 11, 5 .lS4 L. De Galan, Analyt. Chim. Rcta, 1966, 34, 2 .185 H. Malissa, Mikrochim. Acta, 1966, Suppl. 1, 1.lB6 M. Riemann, 2. analyt. Chem., 1966, 215, 407ANDERSON, PIERCE, STODDART, AND WILSON 669chemical analyses of solutions. Methods for determining eighteen elements inassociation with beryllium by a d.c.arc method have been described,ls7and the plasma jet has been used 188 for the spectrometric determination ofsilicon.Fhme photometry. Ramirez-Muiioz 189 has distinguished between sensi-tivity, concentration limits, and dilution limits aB applied to qualitative andquantitative analysis by flame photometry. Kirsten and Bertilsson lgOhave described a continuous, quantitative, ultrasonic nebuliser for flamephotometry and flame absorption spectrophotometry. A high-speed opticalchopping and demodulation system has been developed;lgl a method for theintegration of signal and noise over many optical pulses of flame energy,and for the simultaneous integration of four signal channels has beendescribed.lQ1 Normal flame noise is significantly reduced by integration, andby using an internal standard (e.g., lithium) all signal levels can be referredto known levels regardless of flame variations.Winefordner and co-workers lQ2 have discussed the factors affecting atomic emission flame spec-trometry, including self-absorption, ionisation, compound formation, varia-tion in solution flow-rate and atomisation efficiency, entrance optics, and theeffect of measuring spectral line multiplets. The use of fuel-rich flamesreduced lg3 interference from molecular oxide band-spectra in the determina-tion of sodium in aluminium alloys.Mossbauer spectroscopy. Measurement of the nuclear resonant absorptionof y-rays was first described by Mossbauer in 1957; the fmt chemicalapplications were reported in 1962, and several hundred Papers have nowbeen published. A Review (160 references) covering the progress made in1965 has appeared.lg4 Amongst the advances in instrumentation in 1966may be mentioned a wide-range thermostat,lg5 a high-pressure apparatus,lg6a simple spectrometer,lg7 and the use of an " on-line '' computer.lg8Electron spin resonance.The growth of this technique has been such thatit must now be considered separately from nuclear magnetic resonance.Eargle lS9 has compiled a Review (372 references) covering the periodAugust 1963-4uly 1965, in which time 1000 Papers on this topic werepublished.The use of a digital computer to resolve multi-line spectra has beenlS7 L. Carpenter, R. W. Lewis, and K. A. Hazen, Appl. Spectroscopy, 1966, 20, 44.loo W.J. Kirsten and G. 0. B. Bertilsson, Anulyt. Chem., 1966, 38, 648.lol J. W. Haagen-Smit and J. Ramirez-Mufioz, Analyt. Chim. Acta, 1966, 36,lo2 T. J. Vickers, L. D. Remington, and J. D. Winefordner, Analyt. Chim Acta., 1966,103 R. A. Hine, R. Crawford, J. E. Deutschman, and P. J. Tipton, Analyst, 1966, 91,lo4 J. R. DeVoe and J. J. Spijkerman, Analyt. Chem., 1966, 38(5), 382R.loS B. Sharon and D. Treves, Rev. Sci. Instr., 1966, 37, 1252.lo6 P. Debrunner, R. W. Vaughan, A. R. Champion, J. Cohen, J. Moyzis, and H. G.lQ7 G. M. Bancroft, A. G. Maddock, and J. Ward, Chem. and Ind., 1966, 423.lUB R. H. Goodman and J. E . Richardson, Rev. Sci. Instr., 1966, 37, 283.lgS D. H. Eargle, Aizalyt. Chem., 1966, 38(5), 371R.K. Doerffel and Y .Koe-Hue, Tolunta, 1966, 13, 856.J. Ramirez-Muiioz, Talanta, 1966, 13, 87.469.36, 42.241.Drickamer, Rev. Sci. Instr., 1966, 37, 1310670 ANALYTICAL CHEMISTRYproposed,200 and a new reactor for studying gas reactions has been designed.201Japanese workers 202 have studied the distribution of minor elements inprecipitates, and quinhydrone has been recommended 2O3 as a satisfactorystandard for quantitative measurements of unpaired electron concentration.Nuckar magnetic and nzcclear quadrupole resonance. Lustig and Moniz 204have published a Review (739 references) covering analytical developments innuclear magnetic resonance (n.m.r.) techniques within the period July 1963-June 1965, and Drago 205 has assessed the scope for future analytical develop-ment of nuclear quadrupole resonance (n.q.r.) spectroscopy. A dual-purposen.rn.r.and n.q.r. spectrometer has been designed,206 and other investigatorshave developed a spin-echo spectrometer 207 to study chemical exchange.A variety of organic and inorganic determinations can be carried out rapidlyby n.m.r. by utilising kinetic processes and also line widths and positions;zO8ligand exchange kinetics with EDTA systems have been investigated. 209Martin 210 has reviewed high-resolution proton magnetic resonanceanalysis, and papers have described analyses of alkylene oxide polymers, 211unsaturated fatty acids, H Z diaminotoluene isomer mixt~es,2~3 and food-stuffs.214A coaxial cell 215 enables a reference standard to be examined simul-taneously with the sample under examination.Mass spectrometry.Mclafferty and Pinzelik 216 have published a Review(1171 references) which gives a selection of the 5000 mass spectrometryPapers published in 1965. Two computer-based methods have beendescribed 217 for the resolution of mass-spectroscopic data, and Brunnee 218has developed an inlet system which limits the decomposition of thermolabileorganic substances during the vaporisation process in the ion-source of themass spectrometer. Ionisation corrections applicable to determinations ofimpurities have been investigated 219 and the suitability of a mass spectro-meter for vacuum fusion analysis has been discussed.220Spark-source mass spectrometry has been used 221 to determine 27aoo J.R. Reeder, G. M. Odell, R. E. Sioda, and W. S. Koski, J . Mot. Spectroscopy,201 E. N. Sarkisyan and V. IT. Azatyan, Kinetika i Kataliz, 1966, 7, 362.208 S. Fujiware and I<. Nagashima, Japan Analyst, 1966, 15, 890.203 G. Narni, H. S. Mason, and I. Yamazaki, Analyt. Chem., 1986, 38, 367.a04 E. Lustig and W. B. Moniz, Analyt. Chetn., 1966, 38(5), 331R.206 R. S. Drago, Analyt. Chem., 1966, 38(4), 31A.907 K. H. Abramson, P. T. Inglefield, E. Krakower, and L. W. Reeves, Canad. J.308 R. J. Day and C . N. Reillep, Analyt. Chem., 1966,38, 1323.809 R. J. Kula and G. H. Reed, Analyt. Chem., 19G6, 3&, 697.M. Martin, Chim. analyt., 1966, 48, 119.211 A. Mathias and N. Rlellor, Analyt. Chem., 1966, 38, 472.31% J. M. PurceIl, S, 0. Norris, and H.Susi, Analyt. Chem., 1966, 38, 688.s1s A. Mathias, Analyt. Chem., 1966, 38, 1931.214 R. Koha, Pette ec. Seifen, 1966, 68, 795.215 6. F. Hinton and E. S. h i s , AnaZyt. Chirn. Acta, 1966, 36, 632.216 F. W. McLafferty and J. Pinzelik, Analyt. Chem., 1966, SS(5), 350R.217 D. G. Luenberger and U. E. Dennis, Analyt. Chern., 1966, 38, 715.218 C. Brunn6e, 2. analyt. Chem., 19G6, 217, 333.219 H. G. Short and 13. J. Keene, Talanta, 1966, 18, 297.m o M. L. Aspinal, Analyst, 1966, 91, 33.221 P. F. X. Jackson and J. Whitehead, Analyst, 1966, 91, 418.1966, 20, 141.B. L. Barton, Rev. Sci. Imtr., 1966, 37, 605.Chern., 1966,44,1685ANDERSON, PIERCE, STODDART, AND WILSON 671elements commonly present in titanium dioxide pigments ; the analysis iscompleted in 3 hr.The analysis of iron and low-alloy steel has beenand the application of mass spectrometry to structural analysis of carbo-hydrates has been reviewed.223Several papers described the use of mass spectrometry in conjunctionwith a chromatographic technique: small mass spectrometers have beenused 224 as detectors in gas chromatography systems, and mass spectrometryhas been combined 225 with thermal fragmentation and gas chromatographyin studies of amino-acids.Unsaponifiable fractions from fats were apparently homogeneous whenexamined 226 by thin-layer chromat'ography ; mass spectra revealed, how-ever, that the fractions were mixtures.X-Bay jluorescence spectroswpy and reluted technique?, including electron-probe and X-ray probe methods.In electron-probe microanalysis, a pencil ofhigh-energy electrons is used to bombard defined areas of a surface to obtainelemental analyses with a sensitivity of 100 p.p.m. : a recent Review has beenBeaman 228 has studied the effect of pulse amplitude shifts onelectron-probe intensity ratios ; it is possible to obtain accurate intensitymeasurements and high-peak-to- background ratios. A computer pro-gra1nme,22~ for calculating chemical composition from X-ray data obtainedby electron-probe microanalysis, corrects automatically for absorption,fluorescence, and atomic-number factors. Weinryb and Hourlier 230 havereviewed the applications of electron-probe microanalysis to light elements.Reviews of recent advances in X-ray absorption and emission techniques(637 references),227 and in X-ray diffraction techniques 231 (330 references),have been published. Quantitative aspects 232 of X-ray analysis have alsobeen reviewed.Springer 233 has investigated the loss of X-ray intensitythrough re-diffusion of electrons in microanalyser targets with the aid of acomputer, so that appropriate corrections can now be applied in quantitativeanalyses.The present state and future prospects for X-ray fluorescence deter-minations of trace elements have been reviewed 234 by Russian workers.Andermann 235 has determined inter-element correction factors by a method22a B. J. Keene, Talunta, 1966, 13, 1443.183 K. Heyns, €3. F. Griitzmacher, H. Scharmann, and D. lliiller, Fortschr. chem.2a4 C. Brunnee and L.Delpann, Chem.-Ing.-Tech., 1966, 38, 730; D. Hennenberg226 J. Vollmin, P. Kriemler, I. Omura, J. Seibl, and W. Simon, Microchem. J., 1966,M. A. Abdul-Alim, A. F. Aboulez, &5. B. E. Fayez, and A. R. Seedhrtm, 2. amlyt.227 W. J. Campbell, J. D. Brown, and J. W. Thatcher, Analyt. Chem., 1966, 38(5),a28 D. R. Beaman, Analyt. Chem., 1966, 38, 599.J . D. Brown, Analyt. Chem., 1966, 38, 890.E. Weinryb and P. Hourlier, Chim. analyt., 1966, 48, 219.a31 L. Merritt and W. E. Streib, Analyt. Chem., 1966, 38(5), 493R.a3q N. P. Ilk and L. E. Loseva, Zavodskaya Lab., 1966, 32,543.aaa G. Springer, Mikrochim. Acta, 1966, 887.B'orsch., 1966, 5 , 448.end G. Schomburg, 2. analyt. Chem., 1966,215,424.11, 73.Chem., 1966, 217, 268.416R.E.E. Vsinshtein and Yu. G. Lavrentiev, Zhzcr. analit. Khim., 1966,21,463.G. Andermann, Analyt. Chem., 1966, 38, 82672 ANALYTICAL CHEMISTRYbased on the ratios of differences in the mass absorption coefficients. Storkand Mahr 236 have applied the addition method, for the determination of onecomponent, to total analyses; two calibration samples (as borax melts) arecompared with the borax melt of the material under examination. Of themany applications of X-ray fluorescence analysis, mention is restricted toinvestigations of heavy elements in a light matrix,237 of noble elements insolution, 238 and of zinc in small biological spe~irnens.23~Raman and infrared spectroscopy. Raman spectroscopy has received anew stimulus 240 from the development of pulsed laser excitation, and aReview (368 references) covering the period January 196Uanuary 1966has been published.241An important Paper by Low and Coleman 242 has described the measure-ment at low temperature of infrared emission spectra using multiple-scaninterferometry.This technique is very sensitive; it should prove to beuseful for transmission, reflection, and emission measurements.The other comparatively recent development in infrared technique,attenuated total reflection (a.t.r.), has continued to attract in~estigators.2~3Gottlieb and Schrader 244 have discussed its advantages over other methodsof sample preparation, and have studied dichroism in single crystals andpolymers.The theoretical aspects of attenuated total reflection of partially polarisedand linearly polarised radiation from the surfaces of anisotropic absorbingElms have been considered,246 and this technique has been applied to a studyof the molecular orientation of stretched polypropene films.The use of infrared techniques in conjunction with gas chromatographyhas also received considerable attention.Commercial infrared gas-cells andcombined g.1.c. haps are now available for 0.5 p l . samples, and much smallersamples can yield reasonable spectra with the aid of scale expansion devices,or multireflection gas ~ells.2~7 Low 248 has used a multiple-scan interferencespectrometer 242 to obtain spectra of the effluent from a g.1.c. column; therange 4-40 p can be scanned in 1 sec. with a resolution of about 20 cm.-1.Behrendt and Richtering 249 have published an interesting Paper which mayextend the sensitivity of existing methods; the effect of infrared radiationon a sample is observed after its conversion into a molecular beam.Themethod has obvious applications to studies of the fractions from capillarycolumns and also of gas-phase free radicals.Johnson 245 has used silver membrane filters as supports.256 G. Stork and C. Mahr, 2. analyt. Chem., 1966, 223, 363.237 T. Groot, P. C. M. N. Bruijs, and J. H. T. C. Verbeek, Nature, 1966, 211, 1085.238 F. T. Wybenga and A. Strasheim, Appl. Xpectroecopy, 1966, 20, 247.239 L. Zeitz and R. Lee, Analyt. Biochern., 1966, 14, 191.*4O R. C. Hawes, K. P. George, D. C. Nelson, and R. Beckwith, AnaZyt. Chem., 1966,2 4 1 R.N. Jones and M. K. Jones, dnalyt. Chem., 1966, 38(5), 39312.242 M. J. D. Low and I. Coleman, Spectrochim. Acta, 1966, 22, 369.243 C. G. Ford, Nature, 1966,212, 72; T. Hirschfield, AppLXpectroscopy, 1966,20,336.244 K. Gottlieb and B. Schrader, 2. analyt. Chem., 1966, 216, 307.245 R. D. Johnson, AnaZyt. Chem., 1966, 38, 160:246 P. A. Flournoy and W. J. Schaffers,SpectTochzm. Acta, 1966,22,5; P. A. Flournoy,247 P. A. Hollingdale-Smith, Canad. Spectroscopy, 1966, 11, 107.248 M. J . D. Low, Chem. Comm., 1966, 371.249 S. Behrendt and H. Richtering, J . Chromatog., 1966, 24, 1.38, 1842; A. Lau and J. H. Hertz, Spectrochirn. Acta, 1966, 22, 1935.&bid., p. 15ANDERSON, PIERCE, STODDART, AND WILSON 673With regard to more traditional infrared spectroscopy, the CoblentzSociety has suggested 250 specifications for the evaluation of referencespectra, and a Review (284 references) covering the period December 1963-December 1965 has been p~blished.~~l Biernacka 252 has considered funda-mental aspects of quantitative analysis, and the errors arising when sufficientlypure standards are not available, or when overlapping peaks occur, have beendiscussed.253 Papers have reported determinations of unsaturated end-groups in polyhydroxypropylene glycols,254 of ep0xides,~5~ of hexanolactammonomer in Ny10n-6,~~~ of nitrogen in nitrocell~lose,~~~ of sulphate andnitrate in plutonium peroxide and tetraflu~ride,~~~ of silver carbonate insilver oxide,259 of mixtures of lanthanum and yttrium oxinates,260 and oforganophosphorus pesticides.261 Kiss and Hegedus 262 have studied thecomposition of the complexes formed when molybdenum, titanium, indium,and gallium are extracted with di- or tri-butyl phosphate.Simon 263 hasdiscussed the conjoint use of infrared, mass, n.m.r., and e.s.r. spectroscopyfor determinations of structure.Interest in theXpectrophotornetry.or far-infrared ranges continues to be slight.Boltz and Mellon 265 have given a Review (568references) covering the period October 1963-October 1965, and Svehla 266has discussed the principles, difficulties, and applications of differentialspectrophofometric methods. Kirkbright 267 reviewed the methods forstudying factors affecting the development of a spectrophotometric method,and made some reasonable recommendations relating to the publication ofdata from future studies.A feature of this section was the number of contributions from T.S.West and his co-workers. These included the determination of copper 26s asRose Bengal bisphenanthroliniumcopper(n) in concentrations down to0.002 p.p.m.; of antimony 269 with Bromopyrogallol Red in the range10-100 pg.; and of phosphorus 270 down to 0-2 pg. (0*008 p.p.m.) by anamplification procedure in which phosphomolybdic acid is formed then260 AnaZyt. Chern., 1966, 38(9), 27A.261 J. C. Evans, Analyt. Chem., 1966, 38(5), 311R.r5a T. Biernacka, Chem. Analit., 1965, 10, 1075.*63 I. KossIer and J. Ciiek, Z . analyt. Chem., 1966, 220, 272.264 V. V. Kharkov, Zavodskaya Lab., 1966, 32, 436.a66 J.SouEek and J. Va&tkovb, Coll. Czech. Chem. Comm., 1966, 81, 2860.257 A. Clarkson and C. M. Robertson, Analyt. Chem., 1966, 38, 522.168 A. J. Johnson and E. Vejvoda, Talanta, 1966, 13, 81.269 N. G. Keats and P. H. Scaife, Talanta, 1966, 13, 156.260 R. Neeb, Talanta, 1966, 18, 133.261 R. B. Delves and V. P. Williams, AnaZyst, 1966, 91, 779.26a A. B. Kiss and A. J. Hegediis, Mikrochim. Acta, 1966, 771.a64R. M. Bly, P. E. Kiener, and B. A. Fries, Analyt. Chem., 1966, 38, 217; B. D.266 D. F. Boltz and M. G. Mellon, Analyt. Chem., 1966, 38(5), 317R.a66 a. Svehla, Talanta, 1966, 13, 641.m 7 C. F. Kirkbright, Talanta, 1966, 13, 1.a68 B. W. Bailey, R. M. Dagnall, and T. S. West, Tcdanta, 1966,15, 763.a6@ D. H. Christopher and T.S. West, Talanta, 1966, 13, 507.G. C. Ongemach, V. A. Dorman-Smith, and W. E. Beier, Analyt. Chem., 1966,38, 123.W. Simon, 2. analyt. Chem., 1966, 221, 368.Pearson, Analyst, 1966, 91, 247.V. Djurkin, G. F. Kirkbright, and T. S. West, Analyst, 1966, 91, 89674 ANALYTICAL CHEMISTRYextracted away from excess of the molybdate reagent. The twelve molybdateions associated with the phosphate are then determined a t 710 mp as thegreen molybdenum( VI) complex with 2-amino-4-chlorobenzenethiol inchloroform. Large excesses of silicon, germanium, arsenic, or antimony donot interfere, and interference from up to 30-fold excess of tungsten(vI) canbe prevented by masking.A careful study 271 of the reaction of gold with Dithizone has shown theset o react in the ratio 1 : 1, forming a red-brown complex, and also in the ratio2 : 1, forming a yellow complex.Both complexes are extractable intochloroform, and the proportion of the two complexes formed depends onseveral critical factors. Solutions of chloranilic acid have been found 272 to beof limited stability. A new chelon, the thio-derivative of 2-thenoyltrifluoro-acetone,273 may be useful as a reagent for the colorimetric determination ofzinc, cadmium, mercury(@, and lead(@.Of the organic applications, diphenylpicrylhydrazyl has been found 274to give good results for the analysis of mixtures of phenols; a method fordetermining small amounts (5-60 pg.) of secondary amines has beendescribed which involves 275 nitrosation and solvent extraction into n-hexane; and Bell 276 has reported that p-aminobenzoic acid can be used forthe microdetermination of aldoses and glucosamine.Graphical methods for selecting the optimum range and determining themaximum accuracy of reflectance-spectrophotometric methods have beendiscussed.277Hirschfield 278 has studied applications of the attenuated total reflectancetechnique in the ultraviolet and visible regions.Luminescence spectroscopg. This section embraces spectrofluorimetry,atomic (flame) fluorescence, and phosphorescence measurements.GoodReviews have been published by White and W e i ~ s l e r , ~ ~ ~ and by Hercules.280The merits of photoluminescence methods as analytical techniques have beenadvanced by Parker 2*1 and by Fleury,2*2 and undoubtedly, increasedinterest has been shown in these methods, with outstanding contri-butions being made by the two research groups of T.S. West and J. D.Winefordner .Winefordner and his co-workers have considered the influence of instru-ment design on phosphorescence inten~ity,~*~ and have derived a mathe-matical expression for the integrated luminescence intensity obtained with271 D. A. Beardsley, G. B. Briscoe, J. RbliEka, and M. Williams, Talanta, 1966,27a H. Bode, W. Eggeling, and V. Steinbrecht, 2. analyt. Chem., 1966, 216, 30.273 E. W. Berg and K. P. Reed, Analyt. Chim. Acta, 1966, 36, 372.27p G. J. Papariello and M. A. M. Janish, Anulyt. Chem., 1966, 38, 211.276 T. Uno and M. Yamamoto, Japan Analyst, 1966, 15, 968.276 D. J. Bell, J .Chem. SOC. ( C ) , 1966, 1638.277 V. T. Lieu and M. M. Frodyrna, Talunta, 1966, 13, 1319.278 T. Hirschfeld, Canad. Spectroscopy, 1966, 11, 102; 115.27D C. E. White and A. Weisslcr, Analyt. Chem., 1966, 38(5), 165R.289 D. M. Hercules, Analyt. Chem., 1966, 38(12), 29A.2s1 C. A. Parker, Chem. in Britain, 1966, 2, 160.328.S. Fleury, Chim. onalyt., 1966, 48, 266.T. C. O’Haver and J. D. Winefordner, Aizalyt. Chem., 1966, 38,602.13ANDERSON, PIERCE, STODDART, AND WILSON 675pulsing techniques.284 They have also presented 285 equations which facili-tate optimisation of the following experimental and spectral parameters :the photo-detector signal, signal-to-noise ratio, minimum detectable con-centration, and monochromator slit-width. A further Paper 2S6 showed thata continuous 150w xenon arc source eliminates the necessity for developingindividual intense line sources for the following elements : copper, silver,gold, lead, bismuth, magnesium, zinc, cadmium, thallium, calcium, barium,gallium, and nickel.Finally, McCarthy and Winefordner 287 showed that thefluorescence emission of rare-earth ions in solution is selectively sensitised byaromatic carbonyl compounds, the system being excited by monochromaticlight a t the wavelength of maximum absorption for the phosphorescencetransition of the carbonyl compound.West 288 and his co-workers, like Winefordner,286 used a xenon arc lampto excite the atomic fluorescence of 10 elements, including, for the first time,iron, manganese, and cobalt. Carminic acid was used 289 as a reagent for thespectrofluorimetric determination of molybdenum and tungsten, and otherPapers gave spectrofluorimetric methods for submicrogram amounts ofaluminium 290 and copper.291 West and co-workers also modified z92 aspectrofluorimetric method for scandium, by incorporating a solvent-extraction stage, to extend its use to determinations of scandium in thepresence of the other ions (aluminium, yttrium) that give fluorescent species :the behaviour of other ions that interfere was studied.West 293 reviewedsome of the applications of fluorimetric methods.Goodfellow 294 studied some inter-element effects in atomic fluorescencespectrometry, and other Papers reported fluorometric determinations ofmicrogram amounts of ~ u l p h a t e , ~ ~ ~ and of calcium, magnesium, and iron.296Organic applications included the determination of nanogram quantities ofcarbohydrate^,^^^ and a highly specific and sensitive assay for reducedglutathione.298ChenZg9 has shown that the light scatter in fluorimetry can be reduced bythe use of horizontally polarised excitation.Weber and Bablouzian 800have designed a fluorescence polarisation spectrophotometer to studyproteins.284 T. C. O’Haver and J. D. Winefordner, Analyt. Chem., 1966, 38, 1268.P. A. St. John, W. J. McCarthy, and J. D. Winefordner, Analyt. Chem., 1966,38,286 C. Veillon, J. M. Mansfield, M. L. Parsons, and J. D. Winefordner, Analyt. Chem.,W. J. McCarthy and J. D. Winefordner, Analyt. Chem., 1966, 38, 848.R.31. Dagnall, K. C. Thompson, and T. S. West, Analyt. Chim. Acta, 1966, 36,a8a G. F. Kirkbright, T. S. West, and C. Woodward, Talarttu, 1966, 13, 1637; 1646.290 R. M. Dagnall, R. Smith, and T. S. West, Tala?atu, 1966, 13, 609.2Q1 B. W. Bailey? R. M. Dagnall, and T. S. West, Talantu, 1966, 13, 1661.lS2 G. F. Kirkbright, T. S. West, and C. Woodward, Analyst, 1966, 91, 23.293 T. S. ?Vest, Analyst, 1966, 91, 69.2Q4 G. I. Goodfellow, Analyt. Chim. Acta, 1966, 36, 132.J. C. Guyon and E. J. Lorah, AnaZyt. Chem., 1966,38, 155.296 A. M. Escarrilla, Talanta, 1966, 13, 363.297 C. J. Rodgers, C. W. Chambers, and N. A. Clarke, Analyt. Chem., 1966, 38, 1851.V. H. Cohn and J. Lyle, Analyt. Biochem., 1966, 14, 434.2Qs R. F. Chen, Analyt. Biochem., 1966, 14, 497.* O 0 G.Weber and B. Bablouzian, J . Biol. Chem., 1966, 241, 2558.1828.1966, 38, 204.269676 ANALYTICAL OHEMISTRYQuenchofluorimetry has been applied 301 to the determination of micro-gram amounts of phosphate by its quenching effect on the fluorescence of thealuminium-Morin chelate. The complementary technique, quenchophos-phorimetric analysis, has been reported 302 to be superior to colorimetry andfluorimetry in simplicity, sensitivity, and selectivity for many types ofcompound; many of the reagents used in colorimetry and fluorimetry aresuitable for the quenching technique.Atomic absorption spectroscopy. In this section also, there has beengreatly increased interest in the past year, with an unusually large numberof significant theoretical Papers.There have also been several goodReviews.303Galan and Winefordner 304 have considered theoretical aspects of theiduence of flame temperature on the absorption signal, and two groups ofinvestigators 305 have studied the use of the plasma jet (8000"~) in atomicabsorption work. Induction coupled plasmas have many advantages : e.g.,much higher temperature, longer residence times of the particles in theplasma, the depressant effect of chemical interferences (e.g., formation ofstable refractories) is minimised, and the background radiation of the tailflame of an argon plasma fed by an aqueous aerosol is much less than that ofhydrocarbon combustion flames. Koirtyohann and Pickett 306 also in-vestigated the effects of background absorption, and Yasuda 307 examined therelationship between resonance-line profile and absorbance in atomic absorp-tion spectrometry.Lang 308 investigated the errors due to fluctuations in theoperating conditions of the flame and the sample flow-rate, and described anarrangement whereby intermittent atomisation of sample solution into aturbulent hydrogen-air flame is achieved by periodic interruption of the airsupply. It has been suggested 309 that light-scattering effects in atomicabsorption must be small and cannot account for the loss of light that is ob-served. Other possible sources of loss are mentioned, and it is suggested thatabsorption by molecular species in the flame may be important. Ramirez-Muiioz and co-workers 310 have discussed the factors contributing toincreased slope of the working curve, decreased noise level, improved preci-sion, and elimination of curvature in the working curve a t high concentrationlevels : these factors are fundamental in attempts to increase sensitivity.The application of computer techniques to processing atomic absorption datahas also been studied.311The feasibility of using an iron hollow-cathode lamp rn an atomic301 D.€3. Land and S. M. Edmonds, Mikrochim. Acta, 1966, 1013.303 E. Sawicki and J. D. Pfaff, Mikrochim. Acta, 1966, 322.808 A. Walsh, J . New Zealand In&. Chem., 1966, 30, 7; R. Herrmann, Portschr.a04 L. D. Galan and J. Winefordner, Analyt. Chm., 1966, 38, 1412.305 R. H. Wendt and V. A. Fassel, Analyt. Chem., 1966, 38, 337; K.E. Friend and306 S. R. Koirtyohann and E. E. Pickett, Analyt. Chem., 1966, 38, 685.307 K. Yasuda, Analyt. Chem., 1966, 38, 592.308 W. Lang, 2. analyt. Chem., 1966,223,241; 1966,219, 321.800 S. R. Koirtyohann and E. E. Pickett, Analyt. Chem., 1966, 38, 1087.310 J. Ramirez-Muiioz, N. Shifrin, and A. Hell, Microchem. J., 1966, 11, 204.811 J. Ramirez-Muiioz, J. L. Malakoff, and C. P. Aime, Analyt. Chim. Acta, 1966, 36,chem. Forsch., 1966, 5, 516.A. J. Diefenderfer, ibid., p. 1763.328ANDERSON, PIERCE, STODDART, AND WlLSON 677absorption unit for manganese, magnesium, nickel, and copper has been dis-~ussed.3~~ The difficulties that arise in determinations of magnesium andcalcium, e.g., interference with calcium by vanadate and silicate, and withmagnesium by silicate and titanium 313 have been examined by severalin~estigators.3~~T.S. West and his co-workers have also made significant contributions inthis field, determining cadmium;315 copper in niobium and tantalum;31smolybdenum in niobium and tantalum,317 and in alloy steels,31s using anitrous oxide-acetylene flame. The determination of molybdenum was alsostudied by other workers ;319 the method involved complexing with ammon-ium pyrollidine dithiocarbamate followed by extraction into methyl n-pentylketone. Japanese workers 320 showed that solvent extraction from a ma,trix ofinterfering elements can be of great value in atomic absorption analyses;the solvent extraction need not be highly selective, and methods and reagentsuseless for pure solvent-extraction work may often be of value for thisapplication.Solvent extraction wits used by Dagnall, West, and Young 321 in deter-mining traces of lead in steels, brass, and bronze; the determination of leadwas also studied by other investigators,322 a sensitivity of 0.013 p.p.m.beingattained. Other Papers of note included the determination of tin,323 andand of sulph~r,32~ iron,326 and cadmium 327 in biologicalmaterials.The feasibility of atomic absorption as a detector or complementarytechnique for g.1.c. has been examined.328 Goleb 329 has studied the near-ultraviolet and visible atomic absorption spectra of the noble gases.7. Methods of Separation.-DistiEZation. Newman 330 has found that aborosilicate glass condenser will chemisorb small amounts of ammonia, dur-ing its distillation for isotopic analysis.Since trace residues of samplesof ammonia containing large amounts of 15N will seriously contaminate31a C. W. Frank, W. G. Schrenk, and C. E. Meloan, AnaZyt. Chem., 1966, 38,313 T. V. Ramakrishna, J. W. Robinson, and P. W. West, Analyt. Chim. Acta, 1966,314 R. E. Dickson and C. M. Johnson, Appl. Spectroscopy, 1966, 20, 214; D. J. Halls315 R. M. Dagnall, T. S. West, and P. Young, Talanta, 1966, 13, 803.316 G. F. Kirkbright, M. K. Peters, and T. S. West, Analyst, 1966, 91, 411.317 G. F. Kirkbright, M. K. Peters, and T. S. West, Analyst, 1966, 91, 705.318 G. F. Kirkbright, A. M. Smith, and T. S. West, Analyst, 1966, 91, 700.31s L. R. P. Butler and P.M. Mathews, Analyt. Chim. Acta, 1966, 36, 319.320 T. Takeuchi, M. Suzuki, and M. Yanagisawa, dnalyt. Chim. Acta, 1966, 36,321 R. M. Dagnall, T. S. West, and P. Young, Analyt. Chem., 1966, 38, 358.322 C. L. Chakrabarti, J. W. Robiason, and P. W. West, Analyt. C h h . Acta, 1966,34, 269; H. W. Wilson, Analyt. Chem., 1966, 38, 920.323 L. Capacho-Delgado end D. C. Manning, Spectrochim. Acta, 1966, 22, 1505.324 L. Barnes, Analyt. Chem., 1966, 38, 1083.325 D. A. Roe, P. S. Miller, and L. Lutwak, An.alyt. Biochem., 1966, 15, 313.s26 D. 0. Rodgerson and R. E. Helfer, Clin. Chem., 1966, 12, 339.327 P. Pulido, K. Fuwa, and B. L. Vallee, Analyt. Biochem., 1966, 14, 393.328 B. Kolb, 0. Kemmner, F. H. Schleser, and E. Wiedeking, 2. analyt. Chern., 1966,320 J.A. Goleb, Analyt. Chem., 1966, 38, 1059.s30 A. C. D. Newman, Chem. and Ind., 1966, 115.1005.36, 57.and A. Townshend, Analyt. Chim. Acta, 1966, 36, 278; R. W. Nesbitt, ibid., p. 413.258.221, 166678 ANALYTICAL CHEMISTRYsubsequent samples which contain relatively small amounts of 15N, the useof a silver condenser is recommended.Solvent extraction. Two new devices for solvent extraction have beendescribed by Grus~endorf.~~~ In the first, use is made of a technique involv-ing the counter-gravity movement of the solvent through the solid or liquidmaterial, followed by continuous removal of the solvent from the solution bydistillation. The second approach involves a centrifuging technique. Solventextractions have also been carried out 332 by sucking the solution to beextracted through a thin layer of an extracting agent supported on a fine-grained carrier.Reaction products from the oxidation or reduction of organic compoundsin acetic acid may be isolated 333 from the acetic acid by dilution with waterand extraction with carbon disulphide. Another contribution 334 describedthe use of iso-octyl thioglycolate, €€SCH,*CO,*C,H,,, as a selective reagentfor the solvent extraction of certain metal ions.Scott 335 has reported acolorimetric method for determining tantalum in the presence of niobium andtungsten, by selectively extracting a colourlsss tantalum-pyrogallol complex,in the presence of tetrabutyl- or tetrahexyl-ammonium iodide, into ethylacetate and back-titrating with acidified ammonium oxalate.Ion-exchnge.Walton 336 has published a Review article on ion-exchangechromatography. Ion-exchange resin-loaded paper discs were found 337 toprovide good filtration media for collecting microgram quantities of cationsand anions from solutions. The ions were determined by X-ray fluorescencespectroscopy. The method of paper solubilisation chromatography whichpermits separations of hydrophobic organic nonelectrolytes by developmentwith mixed solvents on ion-exchange papers has been extended 338 to studieson separations of a series of high-molecular-weight ketones. Pietrzyk 339 hasstudied the sorption rates of p-nitroaniline on to hydrogen-form ion-exchangeresins in both nonaqueous solvents and water-organic solvent mixtures.Chelate ion-exchange resins with 8-hydroxyquinoline residues as chelate-forming groups have been described;340 these afford separations of Ru, Zr,U, and Ce.Strickland 341 has published a Review covering theperiod from the second half of 1963 to the early part of 1965 (2484 references).During the past year efforts have been made to assess the properties ofbuffers commonly used €or protein electrophoresis. In one Paper,3*2 theeffects of temperature, concentration, and composition upon pH and con-ductivity values of veronal buffers have been examined.These data may beused to forecast optimum conditions for electrophoretic separations carriedElectrophoresis.331 0. W. Grussendorf, Chem. and Ind., 1966, 52.332 R. Denig, N. Trautmann, and G.Herrmann, 2. analyt. Chem., 1966, 216, 41.989 R. E. Aufuldish, K. 0. Stone, and H. C. Yu, Tulunta, 1966, 13, 318.934 J. S. Fritz, R. K. Gillette, and H. E. Mishmash, Analyt. Chem., 1966, 38, 1869.336 B. B. Scott, Analyst, 1966, 91, 606.as6 H. F. Walton, Analyt. Chem., 1966, 38(5), 79R.8s' W. J. Campbell, E. F. Spano, and T. E. Green, Analyt. Chem., 1966, 88, 987.888 J. Sherma and L. H. Pignolet, AnaZyt. Chim. Acta, 1966, 54, 186.saw D. J. Pietrzyk, Talanta, 1966, 13, 225.a4Q H. Bernhard and F. Grass, Mikrochim. Acta, 1966, 426.3 4 1 R. D. Strickland, AmZyt. Chem., 1966, 38(6), 99R.8 4 1 R. D. Strickland and M. M. Anderson, AnaZyt. Chem., 1966, S8, 980ANDERSON, PIEROE, STODDABT, AND WILSON 679out in veronal buffers. Another contribution has dealt with an investiga-tion of " tris "-acetic acid buEer systems with special reference to their appli-cation in preparative starch-gel electrophoresis.Advances have also been made in apparatus design, and new zone-electrophoretic techniques have been described. Criddle and Thomas 344have examined the application of a thermoelectric cooling device to the dissi-pation of heat produced during thin-layer electrophoresis on Kieselguhr G,silica gel G, and alumina 0 ushg O.OS~-borax solution as electrolyte at fieldstrengths between 25 and 50 v/cm.An apparatus which provides a lineartemperature-gradient on an aluminium block has been used 345 in conjunctionwith starch-gel electrophoresis. The technique has been applied to theanalysis of the collagen-gelatin transition.Finally, Freimuth and Kludas 346have applied a combination of high-voltage paper electrophoresis and centri-fugal paper chromatography to the analysis of amino-acids.Column chromatography. Heftmann 347 has published a Review article onchromatography covering the period December 1963-December 1965 (2329references). Nealey 348 has developed a chromatographic technique whichutilises a column modified to permit the eluting solvent to be used con-tinuously. The solvent is heated under reflux in a flask and allowed tocondense at the top of the chromatographic column. The eluant fromthe column is returned to the flask for recycling. Several Papers havebeen concerned with a reduction in the dimensions of chromatographiccolumns.Consequently the search for more sensitive means of detection osolutes from liquid chromatographic columns has continued. Glass capillarycolumns 3 4 9 s 350 and Teflon capillary columns 351, 352 have been used in con-junction with circulating chain detectors. This method of detection makesuse of a moving chain or band to convey solute from a column into a hydro-gen flame-ionisation detector, after the solvent has been removed by evapora-tion. Haahti and his co-workers have reported 349, 353 modifications of theircirculating platinum and gold chain detectors, aimed a t improving the sensi-tivity and linearity of response, and achieving better stability. A detector inwhich the column effluent is fed on to the rim of a heated brass disc has alsobeen described.354 Mohnke, Schmunk, and Schutze 355 have reported thepreparation and application of ion-exchange capillary columns €or separationsof cations on a micro-scale.The cations in the emuent from the column aredetected by means of an amperometric microcell.Molecular-sieve chromatography. A separate section has been allocated to343 W. Pilz and I. Johann, 2. analyt. Chem., 1966,215, 105.s44 W. J. Criddle and J. D. R. Thomas, J . Chromatog., 1966, 24, 112.T. Hollmkn and E. Kulonen, J . Chromatog., 1966, 21, 464.**13 U. Freimuth and K.-33. Kludas, J . Ch/romatog., 196G, 23, 333.s47 E. Heftmann, Amlyt. Chem., 1966, 38(S), 31R.348 R. H. Nealey, J . Chromatog., 1966, 21, 312.s48 J. E. ICtirkki-iinen, E. 0. Haahti, and A.A. Lehtonen, Analyt. Chem., 1966, 38,3 6 0 J. E. Stouffar, P. L. Oakes, and J. E. Schlatter, J. Gas Chromatog., 1966, 4, 89.a51 P. Vestergaard and J. F. Sayegh, J . Chromatog., 1966, 24, 422.352 E. Nystrom and J. Sjovall, J . Chromatog., 1966, 24, 212.35s E. Haahti, T. Nikkari, and J. Kiirkkiiinen, J . Uas Chromatog., 1966,4, 12.864 T. Cotgreave, Chem. and Ind., 1966, 689.866 M. Mohnke, R. Schmunk, and H. Schutze, 2. analyt. Chem., 1966, 219, 137.1316680 ANALYTICAL CHEMISTRYthis chromatographic technique in view of the interest it has been attractingamong both natural and synthetic polymer chemists. Although molecdar-sieve chromatography, often commonly referred to as ‘‘ gel filtration,” hasbeen widely used by biochemists since 1959, it is only during the last twoyears that the technique has been employed and developed to any extent bysynthetic polymer chemists.Unfortunately some of the latter have appearedto convey the impression that they have been developing a new technique,under the synonym of gel permeation chromatography. The vexed problemof nomenclature has been discussed by Anderson and Stoddart 356 in anarticle reviewing the application of the technique to molecular-weightestimations.Ogston 357 has discussed the mechanisms of interactions of solute mole-cules with porous materials and has suggested the need to distinguish betweena thermodynamic and a hydrodynamic aspect. Mathematical treatmentshave attempted 356, 358 to explain the linear correlations which exist betweenthe elution volumes and the logarithms of the molecular weights.Deter-mann and Michel 358 have extended their treatment to deduce a general equa-tion, for very loosely cross-linked dextran gels (Sephadex G75, G100, and G200),which allows molecular weights of globular proteins to be estimated if the wetdensity of the gel, the void volume of the column, and the elution volume ofone test protein are known. In contrast with the mathematical treatment ofAnderson and S t ~ d d a r t , ~ ~ ~ this Paper does not attempt to interpret mole-cular exclusion processes in terms of steric models.Zone-spreading is an important feature, especially in preparative mole-cular-sieve chromatography. Giddings and Mallik 3s9 have characterisedzone-spreading in terms of a general plate-height equation and have sug-gested how separations on molecular-sieve columns may be improved.Inparticular, they recommend a reduction in column diameter as an aid tomore efficient separations but recognise that this may involve a compromisewith a reduction in sample capacity.A Review article on the application of molecular-sieve chromatography tostudies on biological materials has been published by Andrews. 360 Stouffer,Oakes, and Schlatter 350 have used a glass capillary column packed with cross-linked dextran gels and it circulating chain detector for the analysis ofnaturally-occurring macromolecules. Vitamins K, have been separated s5*on Teflon capillary columns of cross-linked methylated dextran gels. Theeffect of temperature on molecular-weight estimations of proteins has beenfound 361 to be linearly dependent on the molecular weights of the proteins.Molecular-sieve chromatography on columns of polyacrylamide gel hasbeen used 362 to estimate molecular weights of polysaccharides.Further366 D. M. W. Anderson and J. F. Stoddart, Analyt. Chim. Acta, 1966, 34, 401.367 A. G. Ogston, Brit. Med. Bull., 1966, 22, 105.358 H. Determann and W. Michel, J. Chromatog., 1966, 25, 303.359 5. C. Giddings and K. L. Mellik, Analyt. Chem., 1966, 38, 997.360 P. Andrews, Brit. Med. Bull., 1966, 22, 109.361 0. Kirret, I. k r o , and H. Heinlo, Eesti NSV Teaduste Akad. Toimetised. Bilo.362 D. M. W. Anderson and J. F. Stoddart, Carbohydrate Res., 1966,2,104; D. M. W.Seer, 1966, 15, 414 (Chem.Abs., 1966, 65, 20398).Anderson, Sir Edmund Hirst, and J. F. Stoddart, J . Chm. SOC. (C), 1966, 1959ANDERSON, PIERCE, STODDART, AND WILSON 681applications of thin-layer molecular-sieve chromatography to studies on pro-teins 363, 364 and mucopolysaccharides have been reported.Cazes 3G5 has published it Review article on the application of molecular-sieve chromatography to studies of the behaviour of synthetic polymers onhydrophobic gels. The effect of the molecular shape of branched and linearhydrocarbon isomers on the elution volume has been examined,366 and thestructural elements were found to be additive. For broad distributionpolymers, an appreciable concentration effect , which may cause a significanterror in estimations of apparent molecular-weight averages, has been ob-served.367 It is suggested that it may be necessary to extrapolate results fordifferent concentrations to zero concentration to obtain quantitative valuesfor molecular-weight averages.Finally, an important new application ofmolecular-sieve chromatography to calculations of molecular-weight dis-tribution functions has been described.368Paper chromatography. Harding 369 has designed a circuit to assist in thepaper chromatography of unstable derivatives of vitamin B,, and folic acidwhich have to be run at low temperatures under an inert gas in the dark. Atransistorised detector triggers an alarm system when the end of a pre-determined solvent path-length has been reached. The use of a solvent re-development technique involving four or more successive 15- to 20-hr.solvent developments has permitted 370 the separation and isolation of amino-acids by preparative paper chromatography. French, Pulley, Abdullah,and Linden 371 have reported the application of two-dimensional paperchromatography interspersed with enzymic reaction on the paper t o theanalysis of starch oligosaccharides.A new fluorescence method has beendescribed 372 for the detection of some catecholamine and tryptamine deri-vatives on paper. The fluorescent derivatives were eluted from the paperwith 0.1 N-hydrochloric acid and their spectral characteristics measured in afluor o met er .In a general Review article on gradienttechniques in chromatography, Stahl 373 has described a procedure for t.1.c.inwhich a stationary phase of gradient composition across the plate is traversedby the mobile phase. Procedures for the mechanical transfer of compoundsfrom t.1.c. plates and for the determination of substances on t.1.c. plates byspectroscopic methods have also been discussed by Stahl.373 Mixed layersof cellulose and silica gel have resulted in improved separations ofThin-layer chromatography.363 L. A. Hanson, B. G. Johansson, and L. Rymo, Clinica Chim. Acta, 1966,14, 391.s66 J. Cazes, J . Chem. Educ., 1966, 43, A567.867 M. J. R. Canton, R. S. Porter, and J. F. Johnson, J . Polymer Sci., Part B,s6* S . Yamadam, S. Imai, end S. Kitahara, Chm. High PO~YY~+YS (Japan), 1966, 23,8 6 8 N. Harding, J . Chromatog., 1966, 24, 482.37e A.E. Pasieka and J. E. Logan, Canad. J . Biochem., 1966, 44, 149.s71 D. French, A. P. Pulley, M. Abdullah, and J. C. Linden, J . Chromatog., 1966, 24,s7a C. E. Bell and A. R. Sornerville, Biochem. J . , 1966, 98, 1C.37a E. Stahl, 8. analyt. Chem., 1966, 221, 3 . *" N. A. Turner and R. J. Redgwell, J . Chromatog., 1966, 21, 129.G. P. Roberts, J . Chromatog., 1966, 22, 90.J. G. Hendrickson and J. C. Moore, J . Polymer Sci., Part A , 1966, 4, 167.Polymer Letters, 1966, 4, 707.605; L. H. Tung, J . Appl. Polymer Sci., 1966, 10, 375; 1271.271682 ANALYTICAL CHEMISTRYamino-acids, as well as in enhanced sensitivity of the Nsnhydrin sprayreagent.New support phases have been introduced. Maddrell’s salt (a water-insoluble sodium polyphosphate) adheres very firmly to glass and may beused 375 for t.1.c.of amino-acids, carboxylic acids, and sugars when used withsuitable solvent systems. Plaster of Paris strips up to 5 mm. thick haveproved useful 37 for preparative chromatography. Several Papers havedescribed 377 automatic methods for applying samples to t.1.c. plates, andBlume 378 has introduced a vacuum distillation method for the recovery ofsamples following t.1.c. At the moment the method can only be used withcompounds which can be distilled at temperatures within the working rangeof the t.1.c. support material. Should t.1.c. support materials be made avail-able with a greater heat resistance, the method could be extended to sub-stances with lower volatilities.Quantitative evaluation of substances separated by t.1.c.has at-tracted 379-381 considerable attention. Methanolic extracts of silica gelusually give high and inconsistent blanks for absorbance in the U.V. The factthat this can be eliminated 37B by filtration through a 0.45 p synthetic mem-brane filter suggests that the “impurity” in methanolic extracts is Snelydispersed silica gel. Jork 3 8 l has described a method based on the measure-ment of ‘‘ directional reflectance ” of U.V. and visible radiation for the identi-fication of substances on t.1.c. plates.Several Papers published during 1966 have dealt with reversed-phaset.1.c. Separations of mixtures of inorganic ions have been carried out 382 byelution with aqueous acid on a stationary phase of an organic extractantretained on a thin-layer carrier.Di-(2-ethylhexyl) hydrogen phosphate,tri-iso-octylamine, and tri-n-butyl phosphate were used as extractants, andsilica gel and powdered poly(viny1 chloride) as supports. Bark andGraham 383 have attempted to correlate the reversed-phase t.1.c. behaviour ofsome alkylphenols with their chemical structures.Gas chromatography. A Review article on gas chromatography coveringthe period December 1963-November 1965 has been published by DalNogare and Juvet 384 (679 references). Reaction gas chromatography hasbeen reviewed by Beroza and Coad 385 and a comprehensive justificationfor the use of g.1.c. as a supplement and replacement for distillation inlarge-scale fractionations has been given.386Several Papers published during 1966 have described the use of reactor-875 G.Hesse, H. Engelhardt, and D. Klotz, 2. analyt. Chem., 1966, 215, 182.876 A. Affonso, J . ChTomatog., 1966, 21, 332.877 P. J. Curtis, Chem. and Id., 1966, 247; (3. P. Arsenualt, J . Chromatog., 1966,21, 156; F. A. Vandenheuvel, ibid., 1966, 25, 102; E. Von Arx and R. Neher, ibid.,378 P. Blume, Analyt. Biochem., 1966, 18, 372.879 R. D. Spencer and B. H. Beggs, J. Chromatog., 1966, 21, 62.380 D. A. Iceyworth and R. F. Swensen, Tahnta, 1966, 13, 829.381 K. Jork, 2. analyt. Chem., 1966, 221, 17.a82 T. B. Pierce and R. F. Flint, J . Chromatog., 1966, 24, 141.885 L. S. Bark and R. J. T. Graham, Talanta, 1966, 13, 1281.884 S. D d Nogare and R. S. Juvet, Analyt. Chem., 1966, 38(5), 61R.385 M.Beroza and R. A. Coad, J . Qas Chromatog., 1966, 4, 199.886 A. B. Carel and G. Perkins, Analyt. China. Acta, 1966, 34, 83.p. 109ANDERSON, PIERCE, STODDART, AND WILSON 683injection systems. It has been demonstrated 387 that certain pure metals,alloys, carbides, oxides, sulphides, and metal salts may be fluorinatedin situ in a reactor-injection system and quantitatively determined by g.1.c.Davison and Dutton 388 have described a similar procedure for the decom-position of ozonides and analysis of the resulting aldehydic fragments byg.1.c. Many organic compounds, especially those of biological interest,decompose at temperatures which are insufficient for their analysis by g.1.c.Sternberg and his co-workers 389 have described an electrical dischargepyrolyser for use in studies on such compounds.Characterisation ofcompounds is possible from the patterns given by their breakdown fragmentson g.1.c. Analysis of polymers by g.1.c. after oxidation in a short stainlesssteel pre-column has also been reported.3D0Column-packing materials for g.1.c. have also received considerableattention. Tho use of porous polyaromatic beads as column-packingmaterials has been introduced by Hollis 3B1 and subsequently employed byother investigators Sg2 to determine trace impurities in ethylene. Porouspolyaromatic beads have the partition properties of a highly extendedliquid surface and partition appears to involve the entire packing. This is tobe contrasted with conventional g.l.c., where partition is from the gas phaseinto a thin 61m of liquid supported on an impervious solid. Sephadex (LH20) has also been used 393 as a column-packing material for g.1.c. A noveltype of packing which permits fast analysis has been described by Halasz andG e r l a ~ h .~ ~ ~ A highly disperse stationary phase occupying only 2 to 4% of thetotal volume is produced by drawing out glass tubes looselypacked with silica,(particle size = 1 p) to internal diameters of 0.4 mm. The preparation of anew type of packing for g.1.c. where the stationary phase is most probablycovalently bonded to the Celite surface has been described by Abel, Pollard,Uden, and Nickless. 3B5 n-Hexadecyltrichlorosilane is allowed to react withCelits in light petroleum to produce a Celite surface covered with a '' skin ofcombined polymer." Resolution is claimed to be superior to that obtained ina silicone-oil column operated under similar conditions. Open tubularcolumns have continued 3g6 to be used for g.1.c.Finally, a technique hasbeen introduced 397 where the substance to be characterised is used as thestationary phase and the behaviour of volatile test-substances is used tofingerprint it.Two new detection systems are worthy of mention. Bechtold 398 hasla' R. S. Juvet and R. L. Fisher, Analyt. Chem., 1966, 38, 1860.V. L. Davison and H. J. Dutton, Analyt. Chem., 1966,38, 1302.J. C. Sternberg and R. L. Litle, Amlyt. Chem., 1966, 38, 321; J. C. Sternberg,R. G. Schoz, J. Bednarczk, and T. Yarnauchi, Analyt.Chem., 1966, 38, 33L.sD1 0. L. Hollis, AnaZyt. Chem., 1966, 38, 309; 0. L. Hollis and W. V. Hayes, J . Gas8D3 A. Zlatkis and H. R. Kaufman, J . Gas Chromatog., 1966, 4, 240.sQs N. Cockle and G. R. Fitch, Chem. and Ind., 1966, 1970.aD4 I. Halalz and H. 0. Gerlach, Analyt. Chem., 1966, 38, 281.S D 6 E. W. Abel, F. H. Pollard, P. C. Uden, and G. Nickless, J . Chromatog., 1966,22,*06 T. R. Mon, R. R. Forrey, and R. Teranishi, J . Urn Chromatog., 1966, 4, 176.897 T. C. Davis, J. C. Petersen, and W. E. Haines, Analyt. Chem., 1966, 38, 241.sDB E. Bechtold, 2. analyt. Chem., 1966, 221, 262.I. H. Krull, and G. D. Friedel, ibid., p. 1639.Chromatog., 1966, 4, 235.23684 ANALYTICAL CHEMISTRYdescribed detectors based on solid state electrochemical cells which showhigh sensitivities towards halogen- and sulphur-containing compounds.Flame-photometric detection of phosphorus- and sulphur-containing com-pounds in a hydrogen-air flame has also been described.399Mass-spectroscopic analysis of effluents from gas chromatographs hascontinued to attract considerable attention.Molecular sieve 5A has beenused 400 to trap fractions separated by g.1.c. Samples are then desorbed byheating and transferred to a mass spectrometer for analysis. A system usinga Teflon membrane has also been developed; 401 the carrier gas is selectivelyremoved from the column efluent prior to entry into the vacuum system ofthe mass spectrometer.Trimethylsilyl (t.m.s.) derivatives of hydroxy-compounds of biologicalimportance have continued to find applications in analyses carried out by g.1.c.e.g., neutral g l y c o ~ e s , ~ ~ ~ and bases and nucleo~ides.~03 In this connection, theintroduction 404 of bistrimethylsilylacetamide, MeC( OSiMe,):NSiMe,, as ahighly reactive trimethylsilyl donor, should make the preparation of t .m.s.derivatives even more straightforward than they are a t present.The pre-paration and g.1.c. of steroid chloromethyldimethylsilyl ethers have beendescribed.4o5 These ethers may have certain advantages over trimethylsilylethers in view of the special sensitivity of electron-capture detectors towardsorganic halides.8. Gravimetric Analmk-Review articles on gravimetric methods forthe determination of organic compo~nds,4~~ inorganic compounds,4o7 and thenoble metals 40* have been published.have shown that formaldehyde is precipitatedquantitatively with tetrahydrophthalazine in weak acetic acid solution.Concentrations of formaldehyde down to a limit of 3.4 ,ug./ml.may be deter-mined.A theoretical treatment of precipitation equilibrium in the presence of achelating agent has been expanded 410 to include the common ion effect onprecipitation reactions. Mealor and Townshend 411 have confirmed that theprecipitation of barium sulphate a t low concentrations involves a hetero-nucleation process. The same authors have also studied 412 the homogeneousnucleation of barium, strontium, and lead sulphates, and lead carbonate, byparticle counting. In another contribution Bashar and Townshend *13 haveOhme and SchmitzOther aldehydes do not interfere with the method.a90 S.S. Brody and J. E. Chaney, J . CTaS Chromntog., 1966, 4, 42.400 M. Cartwright and A. Heywood, Analyst, 1966, 91, 337.401 8. R. Lipsky, G. G. Horvath, and W. J. McMurray, Analyt. Chem., 1966, 38,402 I. M. Morrison and M. B. Perry, Canad. J . Biochem., 1966, 44, 1115.403 Y. Sasaki and T. Hashizume, Analyt. Biochem., 1966, 16, 1.404 J. F. Klebe, H. Finkbeiner, and D. M. White, J . Amer. Chem. Soc., 1966,88,3390.406 B. S. Thomas, C. Eaborn, and D. R. M. Walton, Chem. Comm., 1966, 408.4013 W. T. Smith, W. F. Wagner, and J. M. Patterson, Analyt. Chem., 1966, 38(5),407 W. H. McCurdy and D. H. Wilkins, Analyt. Chem., 1966, 38(5), 469R.408 F . E . Beamish, Talanta, 1966,13, 773.409 R.Ohme and E. Schmitz, 2. amlyt. Chem., 1966, 220, 105.410 J. J. Kelly and D. C. Sutton, Talanta, 1966, 13, 1573.411 D. Mealor and A. Townshend, Chem. Comm., 1966, 9.412 D. Mealor and A. Townshend, Talanta, 1966, 13, 1069.413 A. Bashar and A. Tow-mhend, Tahnta, 1966, 13, 1123.1585.479RANDERSON, PIEBCE, STODDART, AND WILSON 685compared the precipitation from homogeneous solution procedures, includingthose using urea with the conventional and acetic acid methods for the gravi-metric determination of calcium as the oxalate in the presence and absence ofmagnesium. Morales and West 414 have reported a procedure for the quanti-tative determination of calcium as the fluoride. The method involvesprecipitation from homogeneous solution by hydrolysis of the tetrafluoro-borate ion from buf€er media.Sodium tetrakis-(p-fluoropheny1)borate hasbeen used 415 as a gravimetric reagent for the determination of caesium, andsilver has been determined 416 gravimetrically using 2-methylthiobenzimi-dazole. Precipitations of the metal-Cupferron complexes from homogeneoussolutions have been used 417 for determinations of copper and titanium.A series of N-substituted l-naphthylmethylamines has been investi-gated 418 as a possible source of new organic precipitants for the nitrate ion inaqueous solution. N- (4-Chlorobenzy1)- l-naphthylmethylamine was found tooffer considerable advantages over the conventional reagent, Nitron.9. Titrimetric Analysis.-Review articles on titrimetric procedures forthe determination of organic406 and inorganic compounds407 have beenpublished. Titrations in nonaqueous solutions,419 potentiometric titrations, 420and amperometric titrations p21 have also been reviewed.Beamish 422 haspublished a summary of titrimetric methods for palladium, platinum,rhodium, iridium, ruthenium, and gold, and modern methods €or electricalindication in titrations have also been discussed.423Several Papers during 1966 have been concerned with acid-base titrationsin nonaqueous solvents. One such Paper has examined 494 the absorptionof carbon dioxide by a 5% (v/v) solution of ethanolamine in dimethylforma-mide prior to titration with standard tetrabutylammonium hydroxide inbenzene-methanol solution to a visual end-point with thymolphthalein indi-cator.Pietrzyk and Belisle 425 have evaluated a number of substitutedaromatic sulphonic acids for their use as titrants in nonaqueous solvents. Anonaqueous titrimetric procedure has been developed 426 for the determina-tion of dimethyl sulphate.A study of acid-base indicators in fused potassium thiocyanate and inlithium-potassium nitrate eutectic has shown 427 that many are soluble andproduce similar colour changes, in the presence of certain acidic and basicsubstances, as in aqueous solutions.411 R. Morales and P. W. West, Analyt. Chim. Acta, 1966, 35, 526.415 C. E. Moore, F. P. Cassaretto, H. Posvic, and J. J. McLafferty, Analyt. China.410 B. C. Bera and M. M. Chakrabartty, 2. analyt. Chem., 1966, 223, 169.417 A.H. A. Heyn and N. 0. Dave, Talanta, 1966, 13, 27, 33.418 R. C. Hutton, S. A. Salam, and W. I. Stephen, J . Chem. SOC. ( A ) , 1966, 1573.410 G. A. Harlow and D. H. Morman, Analyt. Chem., 1966, 38(5), 485R.420 D. K. Roe, Analyt. Chem., 1966, 38(5), 461R.4aa F. E. Beamish, Tahnta, 1966, 13, 1053.4a3 G. Kraft, Angew. Chem., 1966, 78, 551.424 P. Braid, J. A. Hunter, IV. H. S. Massie, J. D. Nicholson, and B. E. Pearce,425 D. J. Pietrzyk and J. Belisle, Analyt. Chem., 1966, 38, 969.426 W. M. Banick, jun., and E. C. Francis, Talanta, 1966, 13, 979.427 B. J. Brough, D. H. Kerridge, and M. Mosley, J . Chem. SOC. ( A ) , 1966,Acta, 1966, 35, 1.J. T. Stock, Analyt. Chem., 1966, 38(5), 452R.Analyst, 1966, 91, 439.1556686 ANALYTICAL CHEMISTRYChalmers, Edmond, and Moser 428 have studied the peroxide effect in thedetermination of iron (m) after reduction to iron (II), and have found thathydrogen peroxide is produced if a two-phase reduction system is used in thepresence of atmospheric oxygen. For accurate work, the authors recommendthat the reduction be carried out in an inert atmosphere.Aqueous xenontrioxide in acidic or neutral solutions has been used 429 to oxidise carboxylicacids quantitatively. Thus, carboxylic acids may be determined by iodo-metric titration of the excess xenon trioxide.Betteridge 430 has described the use of conditional constants to predictthe optimum conditions for titration in several complexometric titratiom.Ashton 431 has described the use of tetracycline as a highly sensitive fluor-escent indicator in U.V.radiation for complexometric titrations of calcium,strontium, and magnesium in ammoniacal buffer a t pH 10. The indicator isless sensitive for titrations of cadmium and zinc, and barium could be esti-mated by a back-titration procedure. Methods for the complexometricdeterminations of calcium, magnesium, and nickel (in the presence of cobalt)have been described.432 Pfibil 433 has also reviewed the complexometricdetermination of bivalent metals. Chalmers and Sinclair 434 have given anexplanation of the apparently paradoxical behaviour of heteropoly-acids inthe presence of organic complexing agents, such as tartaric acid, and havedescribed procedures for the determination of silicate and phosphate in thepresence of each other. The depolarisation end-point technique has beenapplied 435 to precipitation titrations.10.Reaction-rate Methods.-Rechnitz 436 has reviewed the kinetic aspectsof analytical chemistry. Greinke and Mark have contributed two interestingPapers. They suggested 437 that the analysis of binary &mine mixtures bydifferential reaction rates with methyl iodide gives a more general reaction,including reaction with tertiary amines, than the phenyl isothiocyanatemethod; they also used 438 proportional equations, where the concentrationof reagents is much greater than that of the reactants, for the conductometricdetermination of closely related mixtures of carbonyl compounds.Benson and Fletcher 439 have outlined a kinetic method for analysingtwo-component mixtures of ethanediol, propane-l,2-diol, and butane-2,3-diol. Willeboorse and Meeker 440 described a rapid method (10 min.) fordetermining the primary hydroxyl content of poly (oxyalkylene) glycols andpoly(oxyalky1ene) sorbitols by pseudo-first-order differential reaction kinet-ics. Other Papers considered an automatic reaction-rate method 441 for the428 R. A. Chalmers, D. A. Edmond, and W. Moser, AnaZyt. Chim. Acta, 1966, 35,404.439 B. Jaselskis and R. H. Krueger, TaZanta, 1966, 13, 945.430 D. Betteridge, Talanta, 1966, 13, 1497.431 A. A. Ashton, Analyt. Chirn. Acta, 1966, 35, 543.432 R. Pgibil and V. Vesely, FaZunta, 1966, 18, 233, 616.433 R. Pfibil, Talunta, 1966, 13, 1223.434 R. A. Chalmem and A. G. Sinclair, Analyt. C h h . Acta, 1966, 34, 412.435 M. S. Jovanovic, F. D. Sigulinsky, and M. Dragojevic, Tala-, 1966, 18, 1276.4313 G. A. Rechnitz, Analyt. Chem., 1966, 38(5), 513R.487 R. A. Greinke and H. B. Mark, Analyt. Chem., 1966, 38, 1001.438 R. A. Greinke and H. B. Mark, AnaZyt. Chem., 1966,88, 340.439 D. Benson and N. Fletcher, Talanta, 1966,13, 1207.440 F. Willeboordse and R. L. Meeker, Analyt. Chem., 1966, 38, 854.441 T. P. Hsdjiioamnou, AnaZyt. C h h . Acta, 1966, 35, 360ANDERSON, PIERCE, STODDART, AND WILSON 687microdetermination of molybdenum, and tho possibility of using differentialkinetics in analytical applications of dialysis. 44211. ThermaJ Methods.-A Review by Murphyu3 has been published.Simmons and Wendlandt 444 used magnetic susceptibility measurements tostudy the thermal dissociation of transition-metal ammine complexes with aview to elucidating reaction mechanism ; they described apparatus forrecording automatically the thermogravimetric analysis curve, the masssusceptibility, and the magnetic moment of the central metal ion, from - 196"to 500" for a single sample.Pa&, Paulik, and Erdey 445 contributed three Papers, in which theyconsidered the standardisation of experimental conditions in thermalanalysis, and reviewed the theoretical considerations and development ofcomplex thermoanalytical methods, Wiedemann 446 discussed some appli-cations of a thermobalance, and the hydrolysis of pyromellitic acid disn-hydride was followed 447 by differential thermal analysis.Sajo and Sipos described 448 an interesting method for the rapid analysisof silicates, in which each component is determined by the temperaturevariation of the solution resulting from the addition, to the test solution, ofselectively reacting reagent. It is claimed that determinations take 4-8min. per component ; the apparatus can ba constructed to give direct readingsof the percentages present.12. lbcellaneous.-The American National Bureau of Standards hasreported 449 that an extensive increase in the range of reference and cali-bration standards is t o become available. New zone-refining techniqueshave been described.450 Two Papers 451 considered concentration pro-cesses; the use of reverse osmosis avoids phase changes, high temperatures,and transfer losses.A useful Review-type Paper 452 has discussed the theory and instru-mentation involved in studies of circular dichroism.The effect on organic substances of electrons from tritium in water hasbeen Carboxylic acids are decarboxylated ; the fragments formedare labelled with tritium and hence traces are detectable. The term " elec-tronic pyrolysis " has been proposed for this process, and its possible analyt-ical uses have been surveyed.442 R, 3'. Broman and R. C. Bowers, Analyt. Chem., 1966, 38, 1512.4,63 C. B. Murphy, Analyt. Chem., 1966, 38(5), 443R.444 E. L. Simmons and W. W. Wendlandt, Analyt. Chim. Acta, I9G6, 35,461.445 J. Paulik, F. Paulik, and L. Erdey, Analyt. Chim. Acta, 1966,34,419; Mikrochim.446 H. G. Wiedemann, 2. analyt. Chem., 1966, 220, 81.447 J. M. Rosenfeld, D. F. Loncrini, and C. B. Murphy, Talanta, 1966, 13, 1139.448 I. Sajb and B. Sipos, 2. analyt. Chem., 1966, 222, 23.44g Analyt. Chem., 19GG, 38(8), 27A.450 W. G. Pfann, C. E. Miller, and J. D. Hunt, Rev. Sci. Instr., 1966, 37, 649.461 Z. Marczenko, Chem. Analit., 1966, 11, 347; J. B. Andelman and M. J. Suess,46a A. Abu-Shumays and J. J. Duffield, Anulyt. Chem., 1966, 38(7), 29A.463 H. Schildhecht and 0. Volkert, 2. analyt. Chena., 1966, 216, 97.Acfa, 1966, 894; Talanta, 1966, 13, 1405.Analyt. Chem., 1966, 38, 351