摘要:

650 Analyst, October, 1967, Vol. 92, $9. 650-652 Determination of Combined Nitrogen in Tungsten Metal Powder BY s. P. AWASTHI, s. SAHASRANAMAN AND M. SUNDARESAN (Analytical Division, Rhabha Atomic Research Centre Trombay, Bombay 74, India) A method for the determination of combined nitrogen in tungsten metal powder, based on the dissolution of the sample in 30 per cent. w/v hydrogen peroxide, the hydrolysis of the nitrides and the fixation of nitrogen as am- monium salts in concentrated hydrochloric acid, has been developed. The coeffkient of variation has been determined to be f5.3 per cent. a t the 75 p.p.m. and 1 8 per cent. at the 30 p.p.m. level. TUNGSTEN forms several nitrides including complex nitrides such as WN, and W,N,,l and, as the presence of nitrogen affects the properties of the metal significantly, a method for the deter- mination of combined nitrogen in tungsten metal powder becomes essential.The only chemical method2 for this determination involves the use of sulphuric acid and potassium sulphate with selenium metal powder as the catalyst. In this paper a method is described for the determination of combined nitrogen by using a more convenient solvent for the dissolution of the sample. The method is based on the dissolution of the sample in 30 per cent. w/v hydrogen peroxide with the usual subsequent procedures of micro-Kjeldahl distillation and spectrophotometric determination of ammonia with Nessler's reagent. The usual method of dissolution of tungsten with alkali is obviously not applicable as the ammonia produced is liable to escape.Tungsten is known to be soluble both in a basic solution of potassium cyanoferrate(II1) and a saturated solution of sodium ~ h l o r a t e . ~ The former could not be used because of resultant loss of ammonia and the latter because the dissolution was too slow. Tungsten metal powder is attacked by 30 per cent. w/v hydrogen peroxide with the formation of two pertungstic acids4 and this reagent has been used in this work for dissolution of the sample. EXPERIMENTAL REAGEXTS- Ammonia- free distilled water. Sodiwz hydroxide, 60 per cent. w/v-Analytical-reagent grade. Hydrochloric acid, 1 + 1-Prepare from analytical-reagent grade hydrochloric acid. Hydrogen peyoxide, 30 per cent. w/v-Analytical-reagent grade. Stautdard anzmonium chloride solution-Dissolve 3.1410 g of ammonium chloride (analytical-reagent grade), dried at 100" C, in ammonia-free water and make up to 1 litre.A 10-ml sample of this newly prepared solution when diluted to 1 litre contains 0.01 mg of nitrogen per ml. Nessler's reagent-Prepare as described in the l i t e r a t ~ r e . ~ APPARATUS- The steam-distillation apparatus used was as described in a previous report.6 PROCEDURE- 10 ml of 30 per cent. hydrogen peroxide. ice - water until the vigorous reaction subsides. 60" C to accelerate the dissolution. excess of hydrogen peroxide from the solution by heating slowly on a hot-plate. carried out under similar experimental conditions. Accurately weigh a 0.5-g sample into a beaker, add 2 ml of 1 + 1 hydrochloric acid and Cover the beaker with a watch-glass and cool it in Transfer to a water-bath at not more than When the sample has completely dissolved, expel the A blank isAWASTHI, SAHASRANAMAN AND SUNDARESAN 651 The solution is then quantitatively transferred to the distillation flask and the ammonium salts present in the solution hydrolysed with 5 ml of 60 per cent.sodium hydroxide. The liberated ammonia is collected in a receiver containing a little distilled water. The distillate should be collected at the rate of 1 ml per minute. After carrying out the distillation for 15 to 30 minutes, the distillate is quantitatively transferred to a 50-ml standard flask and made up to volume. Aliquots made up to the mark in 50-ml standard flasks are then taken, 1 ml of Nessler's reagent is added to each and the colour developed measured on a Beckman DU spectrophotometer at 400mp with 10-mm corex cells against the blank.The amount of nitrogen present is then calculated from a standard calibration graph. RESULTS AND DISCUSSION Table I shows a series of results of the recovery of combined nitrogen on four tungsten powder samples. The coefficient of variation, as calculated from a series of determinations, gave values of f5-3, k7.5, k9.2 and kf.3-0 per cent. at 75, 63, 37 and 30 p,p.m. levels, respectively. TABLE I RECOVERIES OF COMBINED NITROGEN FROM TUNGSTEN SAMPLES (Sample weight about 0.5 g) Sample nitrogen obtained, Mean, deviation, of variation, Combined Standard Coefficient number 1 1" 2 2" 3 3* 4 p.p.m. 81, 76, 71, 72 78, 71, 75 69, 70, 79 79, 77 64, 67, 63, 63 70, 61, 55 63, 69, 73 61, 60 33, 42, 37 36, 35 39, 37, 32 39, 40 31, 32, 32 28, 27 p.p.m.75 75 63 65 37 37 30 p.p.m. f 4.0 f 4.9 & 4.7 & 5.5 * 3.4 f 3-3 f 2.4 per cent. & 5.3 f 6.5 & 7.5 & 8.5 f 9.2 9.0 & 8.0 * Results obtained by dissolution with sulphuric acid - potassium sulphate - selenium mixture.2 As no samples of tungsten metal with known nitrogen contents were available, the accuracy of the method was checked by standard addition. To one of the above samples, standard additions of 10, 25 and 50 pg of nitrogen as ammonium chloride were made and it was analysed as before. The results are given in Table I1 and show good agreement between the expected and the experimental values. The method of standard addition used above may be subject to criticism in this case as the added nitrogen was in the form of a soluble ammonium salt.Therefore the analysis of samples 1, 2 and 3 given in Table I was further checked by the known method in which sulphuric acid - potassium sulphate mixture with selenium metal powder is used. The good agreement between the values obtained by the two methods is a further indication that all of the nitrogen is recovered. TABLE 11 (Sample weight about 0.55 g) ANALYSIS OF SAMPLE NUMBER 4 TUNGSTEN POWDER WITH ADDED NITROGEN Amount of nitrogen In 'tungsten, In additive, Total, Found, Deviation, Number Pg CLg CLg CLg PQ 1 16.5 10.0 26-5 26.0 - 0.5 2 18.0 25.0 43.0 40.0 - 3.0 3 16.5 50.0 66.5 64.0 - 2.5652 AWASTHI, SAHASRANAMAN AND SIJNDARESAPJ Another significant point is whether hydrogen peroxide, although it is a good dissolution agent for tungsten metal, will quantitatively decompose the nitrides present, some of which are reported to be extremely refractory. This is partly answered by the reproducibility of results obtained for all the four samples and partly by the agreement between the results obtained by the two different methods.In the sulphuric acid method dissolution entailed extensive heating to fumes and under these conditions it is reasonable to assume that the nitrides are completely decomposed. In this connection it is also worthwhile mentioning that the solvent hydrofluoric acid - hydrogen peroxide has been used satisfactorily for the determination of nitrogen in n i ~ b i u m . ~ The possibility of the loss of nitrogen by oxidation with hydrogen peroxide is also ruled out by the agreement between the results obtained by the two methods.Experiments were performed to determine the effect of temperature, concentration of hydrogen peroxide and the addition of mineral acids. The rate of dissolution was increased significantly up to 60” C ; thereafter the spontaneous decomposition of hydrogen peroxide tended to slow the reaction. Hence it was decided to use 60” C as the optimum temperature of dissolution. The concentration of hydrogen peroxide used was 30 per cent. as the reaction was most effective at this concentration and dilution tended to decrease the velocity of the reaction. Although it was found that the addition of hydrofluoric acid, hydrochloric acid, sulphuric acid or perchloric acid, did not increase the rate of dissolution, experiments without mineral acids gave low recoveries because the fixation of nitrogen could not be effected during the reaction. The presence of 1 to 2 ml of 1 + 1 hydrochloric acid solution prevented this occurring. The authors thank Dr. V. T. Athavale, Head of the Analytical Division, for his helpful suggestions and keen interest during the progress of the work. REFERENCES 1. 2. 3, 4. 5. 6. 7. Li, K. C., and Chung Yu Wang, “Tungsten,” Third Edition, Reinhold Publishing Corporation, “Handbuch fur das Eisenhuttenlabovatorium,” Second Edition, Volume 2, Verlag Stahleisen M.B.H., Li, K. C., and Chung Yu Wang, op. cit., p. 273. Richardson, E. J., Less Common Metals, 1960, 2, 360. Vogel, A. I., “A Textbook of Quantitative Inorganic Analysis,” Second Edition, Longmans, Green “Determination of Combined Nitrogen in Zirconium Metal,” U.K. Atomic Energy Authovity Report Jaworowski, R. J., AnaZyt. Chem., 1966, 38, 1605. Received October loth, 1966 New York, 1955, p. 304. Dusseldorf, 1966, p. 275. and Co., London, 1951, p. 643. IGO-AM/S-17, H.M. Stationery Office, London, 1959.

ISSN:0003-2654    

DOI:10.1039/AN9679200650

出版商:RSC    

年代:1967

数据来源: RSC

摘要:

AmaZyst, October, 1967, Vol. 62, $$. 653-656 653 The Accurate Metering of Gas Flow for Pyrolysis Experiments in a Controlled Atmosphere BY J. BASSETT AND J. W. BETTS (Cheunistvy Depavtunent, Woohich Polytechnic, London, S.E. 18) The modification of a thermogravimetric balance for pyrolysis studies in a controlled atmosphere is described, together with the way in which the apparatus enables gas flow to be measured accurately. The effect of variable flow-rate of the gas on the pyrolysis of calcium oxalate monohydrate under both air and nitrogen atmospheres is presented and discussed. WE have recently had occasion to modify a Stanton HT-SM thermogravimetric balance for pyrolysis studies at up to 1000” C in an inert atmosphere. An upward flow of gas through the furnace was chosen since, as pointed out by Smith,l this has the advantage of carrying pyrolysis products away from the balance and avoids possible condensation of volatiles on the lower, and relatively cool part of the rise rod (weight transfer rod).The accurate measurement of the gas flow leaving the furnace requires the removal of volatile products of pyrolysis before passing the gas through a flow-meter; this is effected by passing the gas through a series of cold traps inserted between the furnace and the flow- neter. It seemed to us that the ability to check, at any time during a pyrolysis run, the ctual flow of gas leaving the furnace would be helpful. The apparatus described here enables this flow to be accurately measured. DESCRIPTION OF APPARATUS A sectional view of the modified thermobalance is shown in Fig.1. The baffle plate originally fixed to the bottom of the furnace housing was removed and a standard silica inner sheath was fitted to the bore of the furnace by using the annular asbestos ring shown. The dome of the sheath was well lagged with asbestos to minimise heat loss and consequent upward movement of the furnace hot zone. The fitting of the silica sheath isolates the furnace thermocouple, T,, from the im- mediate environment of the sample and it becomes necessary to use a new thermocouple, T,, for the measurement of the temperature at the base of the sample (this thermocouple assembly is supplied by Stanton Instruments Limited). The millivolt output from T, is fed first to the balance cold junction, via a compensated cable, and then to a potentiometric recorder (modified Leeds and Northrup Speedomax W) .A gas-inlet base plug was centrally fixed to one end of a mild-steel support tube with flanged ends, and the other end of this tube was bolted to the top baffle plate on the roof of the balance casing. When operating the thermobalance the furnace is lowered so that the base of the sheath fits round the base plug; the dimensions of the support tube are such that the crucible is correctly positioned in the hot zone of the furnace. The gas flow through the apparatus is shown in Fig. 2 . Inflowing gas is dried by using potassium hydroxide pellets before passing it through the 0 to 500 ml per minute “In” flow- meter, M,; the flow being adjusted by means of valve V,. The drying bottles, D, and D,, are fitted with B7 Quickfit joints to facilitate ease of removal for re-filling. The gas sub- sequently enters the furnace sheath through the base-plug gas inlet; in order to prevent the intake of air through the aperture around the rise rod, it is essential that an excess of gas should flow into the base of the furnace sheath, e.g., to achieve a flow-rate of 100ml per minute from the top of the sheath, gas is passed into the base plug at a flow-rate of 200 ml per minute.The hot gas is drawn from the top of the furnace by a vacuum pump (housed in a sound- proofed casing fixed to anti-vibration mountings) and initially passes through silicone rubber tubing. The gas may then be directed either along the main flow line, or through the branch654 BASSETT AND BETTS: ACCURATE METERING OF GAS FLOW FOR [A%a&St, VOl.92 R = Annular asbestos ring C = Sample crucible T, = Furnace thermocouple T, = Sample thermocouple S = Silica inner sheath P = Asbestos base-plug gas inlet T = Support tube = Asbestos packing Fig. 1. Sectional view of the modified thermobalance Gas DI D2 .I I Furnace D, and D, = Drying bottles V, = Flow-control diaphragm valve MI = “In” flow-meter, 0 to 500 ml per minute M, = “Out” flow-meter, 0 t o 150 ml per minute Vz ,V, and V, = Diaphragm valves A I CI c2 F To + Pump M3 1 C, and C, = Cold traps F = Filter bottle V, = Vacuum needle valve M, = “Control” flow-meter, 0 to 500 m l per minute Fig. 2 Gas-flow line diagramOctober, 19671 PYROLYSIS EXPERIMENTS IN A CONTROLLED ATMOSPHERE 655 containing the 0 to 150 ml per minute “Out” flow-meter, M,.Volatile pyrolysis products are removed in the cold-trap section and any solid particles carried in the gas stream are removed by a glass-wool filter; wide-bore inlet tubing is used in the first cold trap to prevent blockage by condensing materials. Heavy-walled rubber pressure tubing is used throughout the apparatus (apart from the short length of silicone rubber) and all joints are clipped and sealed with collodion. In setting up a pyrolysis run, the gas leaving the furnace sheath is directed through the “Out” flow-meter by opening valves V, and V, and closing valve V,. The needle valve, V,, is adjusted to give the desired flow-rate, as indicated by flow-meter M,, and the reading on the “Control” flow-meter, M,, is also noted.Valve V, is now opened, valves V, and V, closed, and the flow maintained at the value previously noted on flow-meter M,. Flow-meter M, must not be left “in circuit” during the experiment as condensation of volatile pyrolysis products may occur with resulting blockage of this flow-meter; it may, however, be momen- tarily brought “into circuit” in order to check the flow of gas leaving the furnace. We have found that a partial blockage of the gas flow may not be shown by the reading on the “Control” flow-meter, M,. The incorporation of flow-meter M, enables a check to be made of the actual gas flow leaving the furnace. PYROLYSIS OF CALCIUM OXALATE MONOHYDRATE Simons and Newkirk, in their detailed study of the pyrolysis of calcium oxalate mono- hydrate concluded that this substance was ideally suited for illustrating many of the factors that govern the form of thermogram obtained.We have studied the effect of variable flow-rate on the pyrolysis of this compound under both air and nitrogen atmospheres. The samples used for all experiments were obtained by sieving (85 mesh) B.D.H. labora- tory-reagent grade calcium oxalate monohydrate and drying it at 70” C. The same platinum crucible was used for each pyrolysis run and care was taken to pack the 200-mg sample in the crucible in a consistent manner. The heating rate was 250” C per hour, so that the only variable factors were the nature of the atmosphere and the flow-rate of the gas. Three pyrolysis experiments were carried out under each type of atmosphere, with flow-rates of 50, 100 and 150 ml of gas per minute; for comparison purposes a pyrolysis run under a static air atmosphere was also performed.The procedural and final temperatures for each decomposition stage in the pyrolysis, as indicated in Fig. 3, are given in Table I. THE EFFECT OF GAS FLOW-RATE Atmospheric air Procedural temperature, TI . . Final temperature, T, . . . . Reaction interval . . . . Procedural temperature, T, . . Final temperature, T4 . . . . Reaction interval . . .. Procedural temperature, T, . . Final temperature, T, . . . . Reaction interval . . . . Oxygen-free nitrogen Procedural temperature, TI . . Reaction interval . . . . Procedural temperature, T, . . Reaction interval . . . . Procedural temperature, T5 . . Reaction interval .. .. Final temperature, T, . . . . Final temperature, T4 . . . . Final temperature, T, . . . . ON . . . . . . . . . . . . . . . . . . . . . . .. . . . . .. .. .. . . TABLE I THE PYROLYSIS OF CALCIUM OXALATE MONOHYDRATE 50 ml per minute, “C 161 23 1 70 401 471 70 666 830 164 50 ml per minute, “C 124 218 94 408 501 93 632 842 210 100 ml per minute, “C 152 229 77 410 468 58 653 827 174 100 ml per minute, “C 126 220 94 406 516 110 648 835 187 150 ml per minute, “C 149 222 73 413 465 52 640 823 183 150 ml per minute, “C 118 218 100 40 7 515 108 65 1 830 179 Static, “C 161 229 68 40 1 483 82 670 853 183656 BASSETT AND BETTS DISCUSSION OF RESULTS It is seen that the procedural and final temperatures, T, and T,, corresponding to the dehydration of calcium oxalate monohydrate are significantly lowered when using a higher flow-rate (100 and 150 ml per minute) of air.This is probably because of the more rapid removal of water vapour from the immediate vicinity of the sample. The changes in T, and T, observed with an increased rate of flow of nitrogen are hardly significant; this feature may be related to the fact that the dehydration proceeds at an appreciably lower temperature under a nitrogen atmosphere than under air. The exothermic nature of the decomposition of anhydrous calcium oxalate under air3 9, probably accounts for the observed reduction of the reaction interval, T, minus T,, with an increasing rate of flow of air. The rate of decomposition is clearly increased by an enhanced supply of air, although the lowering of T, at higher flow-rates may also be partly caused by the more effective removal of carbon monoxide and dioxide from the environment of the sample.Under an inert nitrogen atmosphere the decomposition is endothermic and it is seen that the reaction interval is substantially larger than under air. A feature of the endothermic decomposition of calcium carbonate is that the final tem- perature, T,, decreases with increasing flow-rate under both air and nitrogen atmospheres. The substantial lowering of T,, on passing from a static to a dynamic air atmosphere, confirms that the chief effect of an increased flow-rate is to promote the more rapid removal of carbon dioxide. Simons and Newkirk, reported that the pyrolytic behaviour of calcium carbonate pro- duced by the decomposition of a given sample of calcium oxalate was determined by the atmosphere in which it had been formed rather than the atmosphere in which it was decom- posed. The different variation of the procedural temperature, T,, with increased rate of flow of air and nitrogen may well be a consequence of differences of particle size, surface area or other characteristics of the calcium carbonate sample. The results obtained in this work clearly indicate the significance of gas flow-rate for pyrolysis studies under a controlled atmosphere and emphasise the need for accurate metering of the gas flow. We thank Mr. C. Rowden for his work on the modification of the thermobalance. REFERENCES 1. Smith, D. A., Analyt. Chem., 1963, 35, 1306. 2. 3. 4. Simons, E. L., and Newkirk, A. E., Talaxta, 1964, 11, 549. Erdey, L., and Paulik, F., Acta Chim. Hung., 1955, 7, 27. Wendlandt, W. W., J . Chem. Educ., 1961, 38, 571. Received A p ~ i l 27fh, 1967

ISSN:0003-2654    

DOI:10.1039/AN9679200653

出版商:RSC    

年代:1967

数据来源: RSC

摘要:

ArtaZyst, October, 1967, Vol. 92,p. 657 657 Book Reviews HANDBUCH DER MIKROCHEMISCHEN METHODEN. Edited by FRIEDRICH HECHT and MICHAEL K. ZACHERL. Volume IV. ELEKTRONENSTRAHL-MIKROANALYSE. By HANNS MALISSA. Pp. viii + 164. Vienna and New York: Springer-Verlag. 1966. Price (cloth) $12.25; subscription price $9.90. Electron-probe microanalysis is a technique that is becoming increasingly popular in analysis, not only for metallurgical samples, but also for other inorganic materials and for biological systems. Professor Malissa has therefore produced a timely account of the present state of development of the technique, which will be of value both to those who use the method and to those who merely wish to be informed of recent developments and potentialities. The monograph gives a comprehensive description of the theory behind the method, followed by an account of the instrumentation required.This includes a detailed comparison of several commercially available instruments, especially the J .E.O.I.L. “ JXA-3” (Japan), Cameca “MS 46” (France), ARL “Mark 11” (U.S.A.), Cambridge “Geoscan” and A.E.I. “SEM-2” (U.K.). A dis- cussion of the manner and scope of analyses with the electron probe occupies the remainder of the text. Each chapter concludes with numerous literature references. And even although it is written in German, the inefficient linguist (like The book is well produced and liberally illustrated.658 BOOK REVIEWS [Analyst, Vol. 92 myself) will find it surprisingly readable. The only criticisms that can be raised are minor ones.The subject index is rather brief, and the price is rather high for a book of this size. A. TOWNSHEND KIRK-OTHMER ENCYCLOPEDIA OF CHEMICAL TECHNOLOGY. Second Edition. Volume 10. FOOD ADDITIVES TO HETEROCYCLIC COMPOUNDS. Edited by HERMAN F. MARK, JOHN J. MCKETTA, JUN., DONALD F. OTHMER and ANTHONY STANDEN. Pp. xiv + 938. New York, London and Sydney: Interscience Publishers, a division of John Wiley & Sons Inc. 1966. Price LlS 15s. ; price per volume for subscribers to the complete set of 18 volumes L15. As the tenth volume in this series, the publication now under review starts on the second half of the ground to be covered by the 18 volumes which comprise the complete work (see Analyst, 1963, 88, 899, et seq.). This portion of the alphabetical spectrum of chemical technology happens to cover subjects of particular interest to chemists concerned with a wide range of important industries.It happens, moreover, that many of these activities have important analytical implica- tions, and in consequence the monographs concerned are likely to be of especial interest to members of the Society for Analytical Chemistry. It should, however, be made clear that in no case is the analytical side of the subject treated a t any great depth; nevertheless, the background information on a particular subject essential to the proper understanding of its analytical problems is presented in a comprehensive and authoritative form, and it is on these grounds that the present volume is especially recommended to members. Some examples of the type of subject to which this applies are as follows : Additives and Food Standards, Fruit Juices, Fuels, Fungicides, Gelatin, Glue, Glycerol, Gums and Hair Preparations. On the other hand, there is the usual sprinkling of alphabetically surprising fringe subjects, such as the monographs on Friction Material (concerned chiefly with brake linings and clutch facings) ; Gems (Synthetic), which covers not only diamonds, well known in this capacity, but also emeralds, sapphires, rubies and less romantic “gems” as spinel and titania ; and Gravity Concentra- tion, a broad term used to describe upgrading processes in which the force of gravity or centrifugal force is used to separate particles of a selected specific gravity (treated largely as an engineering subject).Heat Transfer comprises two monographs, the first dealing with the theory of the subject and its relevance to water as a medium, and in particular to steam raising and water heating; the second is concerned with media other than water used for high level heat transfer, as petroleum products, proprietary mixtures such as those containing diphenyls or glycols, mercury and even molten salt mixtures and fused metals. So-called low level heat transfer involves media such as organic salts, brines and (for snow melting) a petroleum oil or a glycol. It will be seen that this is a very informative monograph despite its limited chemical significance. Of the monographs mentioned above as being of special interest to members of the Society, reference should be made to the four articles dealing with food, namely additives, processing, diet and standards.The background of three a t any rate of these is, understandably, the American food laws and the joint FAO/WHO/Codex Alimentarius Commission, which is concerned with both additives and with food standards, and is preparing a collection of internationally adopted standards to protect consumer health and to ensure fair practice in the food trade. It is a measure of the wide range of modern organic chemistry that separate monographs comprising 43, 32 and 14 pages, respectively, are given to Heterocyclic Compounds, the Friedel- Crafts Reactions and the Grignard Reaction ; however, Guanidine and its Salts receives only 7 pages. The first of these monographs gives rise to some problems of nomenclature, the “oxa - aza” system developed in 1925 and recognised in 1930 by the then International Union of Chemistry, being adopted in the present instance.The monograph on Fruit Juices (11 pages) is also largely American in approach, but it contains a comprehensive table of properties which includes some products not commonly known in this country. Methods of manufacture are dealt with, but superficially. The two short monographs on Fungicides discuss agricultural and industrial applica- tions, and the title is interpreted in its narrow sense, i.e., as chemicals capable of killing or inhibiting fungi. Industrial applications include oil-borne and water-borne wood preservatives, and applica- tions to textiles, paints, leather, pharmaceuticals and paper.The monograph on Furs and Fur Processing is also fairly short (17 pages), but very informative, especially to the reader having general interests. It covers briefly most of the operations of dressing, tanning, preparation for bleaching and dyeing with oxidation or vegetable dyes, followed by finishing, cleaning and storage. Mention might well have been made of the risks of dermatitis arising from the use of oxidation dyes without efficient washing. In the same category may be considered Hair PreparationsOctober, 19671 BOOK REVIEWS 659 (36 pages), which covers the usual cosmetics ranging from shampoos to hair straighteners. The relative merits of detergents, anionic, non-ionic and others, and soap, in shampoos, is well dis- cussed; and there are knowledgeable sections on hair sprays and sets and waving lotions. As with fur dyeing, stress might well have been laid on the disastrous effects that can arise from the unskilled use of oxidation-dye type colourings and bleaching agents.There is a section quoting the laws and regulations of the Federal Food Drug and Cosmetic Act, and these are discussed. Gas, manufactured and natural, and gas cleaning (three monographs, comprising 134 pages) has certain topical interests, and it is interesting to note that natural gas was first observed and used (in Japan) as early as 615 B.C. According to the statistics given, the United Kingdom marketed 35 million cubic feet of such gas in 1959. The section on chemical uses of natural gas is of special interest in view of the fact that, throughout the world, the natural gas industry is a major supplier of fuel and hydrocarbon feed-stocks for the chemical industry; it gives point to the controversy between the use of natural gas in England for domestic purposes as distinct from chemical industry.The “stop press” news of the monograph is the discovery of natural gas on a large scale in the Netherlands, so that the North Sea activities are not mentioned. Events move so rapidly these days that the forecast that the share of natural gas in the total European energy market may increase to 6 per cent. by 1970 (as compared with 2.5 per cent. a t the date cf the monograph) may well be an underestimate. However, the generalisation that the rate of growth of the industry will be regulated by governments to avoid a sudden disruption of an economy directly dependent on other types of fuel, is probably indisputable.Gasoline and other motor fuels understandably earn a monograph some 34 pages long. This also includes a section on natural gas, and it is interesting to note that large numbers of stationary diesel engines are operated on the dual fuel principle with natural gas as a primary fuel and a small charge of diesel fuel for compression ignition. The monograph on Hardness has nothing to do with water, but is concerned solely with solid materials such as metals, wood, etc., and is therefore largely engineering in character. Gold and Gold Compounds, surprisingly, comprise only 15 pages (as compared with Gallium and Gallium Compounds, 19 pages). There is a good deal of physical data on Galliuni Alloys but the uses are confined to the preparation of semi-conductor compounds, such as gallium arsenide, which has the interesting electrical property of high electron stability ; this application promises to become one of the principal outlets for gallium if certain difficulties can be overcome.Present production is about 1 ton per annum. It will be seen that this volume is a fund of useful knowledge to the chemist having general interests, quite apart from its analytical implications. JULIUS GRANT INTRODUCTORY DESCRIPTIVE CHEMISTRY. SELECTED NONMETALS, THEIR PROPERTIES AND BEHAVIOUR. By RONALD C. JOHNSON. Pp. x + 144. New York and Amsterdam: W. A. Benjamin Inc. 1966. Price (cloth) $5.45; (paperback) $2.45. This book is a brief introductory account of the chemistry of hydrogen, nitrogen and the halogens, and their compounds.Intended for the first-year college student in the U.S.A. it overlaps preliminary stages of university work in the U.K. and certain aspects of inorganic chemistry covered by the better advanced-level student. It is one of about fifteen monographs on general chemistry prepared under the editorship of Russell H. Johnsen. Each is intended to be complete in itself: “far more comprehensive in coverage than is permitted by the limitations of the standard one- volume text.” This is an extravagant claim. There are seven chapters. The first is a general introduction and the last, Other Nonmetals, no more than a reading-list with advice on reading in the subject. The intervening chapters are on Hydrogen (including water and other hydrides) , Boron Hydrides, Nitrogen, Fluorine and Halogens.Each chapter has a supplementary reading-list and problems, although numerical answers are not included. Bond diagrams are clear and enhanced by judicious use of colour. The Stock Notation is adopted. Misprints and similar errors are few: I, (instead of I) in figure 1-2 (p. 5 ) ; equations 3-8 (p. 56), 6-2 (p. 114) and 6-11 (p. 117) do not balance; [OH-] must be squared in the equilibrium constant expression 6-12 (p. 117) and ratioactive has crept in on p. 65. The book must be assessed against a background of Introductory “Principles of Chemistry” texts from the U.S.A. and it is undoubtedly interesting and worthwhile. Electronic theory, elementary bonding theory (mainly s, p orbitals and n-bonding) and the ability to use half-cell electrode potentials are assumed a t elementary level, Compression in style has led to some oddities : The volume is attractively produced and easy to read.660 BOOK REVIEWS [Analyst, Vol.92 formulae are occasionally used instead of names ; “bismuths” (etc.) instead of “atoms of bismuth”; “neon, a non-hydrogen-bonded substance . . .”; “As a gaseous molecule, water exists in individual units having structure (I) .” The term unique is overworked. The account of Crystalline Structure, although adequate, would be improved with more detailed explanation, and a footnote explaining the system used in depicting bond diagrams would be welcome. There is much to commend. Reactions of water are well classified. Discussion of the structures (and related properties) of oxides and oxyacids of nitrogen is notable.Fluorine chemistry develops into a study of noble gas fluorides and the proposition that determination of the as yet unknown structure of xenon hexafluoride, XeF,, will provide a test of the rival merits of molecular orbital and valence bond theories. Oxy-ions of bromine are prominent in the Halogens chapter. The index is comprehensive. B. J . MOODY INSTRUMENTAL METHODS IN ANALYTICAL CHEMISTRY, THEIR PRINCIPLES AND PRACTICE. Volume 1. Electrochemical Methods. By M. DONBROW, PH.D. Pp. xii + 291. London: Sir Isaac Pitman and Sons Limited. 1966. Price 50s. Modern trends in analytical chemistry are, unquestionably, in the direction of innovations in instrumentation, together with improvements and extensions in those instrumental fields that are now part of our everyday life.It is, therefore, essential that the undergraduate and the uninitiated should, a t least, have a basic understanding and an appreciation of the uses and limitations of the methods involved. To what extent the subject matter of any new book is already covered by existing publications is often a debatable point. Some books are too brief in parts, others too detailed for the non- specialist or the analyst who wants a “refresher,” and all, inevitably, reflect on the professional status of the author. In the field of electrochemical methods, this book has commendable features covering all these aspects, and the diagrams are excellent.The main emphasis of this volume (volume I1 deals with optical methods) is on potentiometry, polarography, coulometry and conductimetry, and a sensible balance has been established within the various subject headings, on such aspects as theory, apparatus, applications, errors, accuracy and precision. Summarising, this reasonably priced book is highly recommended to anyone for whom a readable account of the theory and practice of electrochemical methods is essential, or desirable. W. T. ELWELL MODERN ASPECTS OF ELECTROCHEMISTRY. Number 4. Edited by J. O’M. BOCKRIS. Pp. viii At a time of rapidly growing interest in electrochemistry, the fourth volume of this series focuses attention on electrodics, the study of charged interfaces, because of its ubiquity and the current importance of energy conversion and storage.The value of the application of the thermo- dynamics of irreversible processes to electrochemistry is controversial, and Van Rysselberghe argues strongly and plausibly in favour, in the first chapter (46 pages), of pressing thermodynamics as far as it will penetrate into the intricacies of electrochemical phenomena. He reviews the essentials of the thermodynamic treatment of galvanic cells and electrodes out of equilibrium, and gives a detailed account of the thermodynamic approach to electrode kinetics on the basis of the Marcelin - De Donder method. Piersma and Gileadi deal with the mechanism of electrochemical oxidation of organic fuels in the second chapter (129 pages). They conclude from a survey of the literature that “much of the work is filled with errors, partly due to misconceptions and partly due to incorrect observations, since most of the research, even a t the present time, has been carried out in a very superficial manner,” and they “attempt to clarify the type of information which is required for mechanistic interpretation, the experimental methods by which this information is most profitably obtained, and the treatment of this information once i t has been obtained.” They discuss experimental methods, adsorption, mechanisms, and the influence of molecular structure on reaction rates.The sophisticated topic of ionic and electric currents at high fields in anodic oxide films is discussed by Young, Goruk and Zobel in chapter 3 (75 pages). Current views on the structure of anodically formed oxide films are summarised, and the transport of ions in high fields in oxide layers on metals and semiconductors in contact with electrolyte solutions is treated, followed by a detailed account of electronic currents through sandwich structures of the metal - oxide - metal counter electrode type.Finally, Wenglowski, an economics research student, con- + 316. London: Butterworths. 1967. Price 86s.October, 19671 BOOK REVIEWS 661 tributes an economic study of the electrochemical industry in the United States (56 pages). Although this study appears rather strangely and uneasily in a series of papers of academic intent, it is of interest to note that classical electrochemistry accounts for over 10 per cent. of the chemical industry, including the petroleum industry, and that it is relatively very badly served with graduates and particularly doctorals.The flavour of this volume is distinctly different from that of its predecessors in that each chapter, while making its review contribution, also presents a challenge that might excite some to fury, but will, it is hoped, incite others to furious endeavour. E. BISHOP ADVANCES IN ELECTROCHEMISTRY AND ELECTROCHEMICAL ENGINEERING. Volume 4. Electro- chemistry. Edited by PAUL DELAHAV and CHARLES W. TOBIAS. Pp. xii + 389. New York, London and Sydney: Interscience Publishers, a division of John Wiley & Sons Inc. 1966. Price 120s. The fourth volume of this series amply maintains the standard of the earlier volumes. It contains five reviews by leading authorities on topics well chosen for current interest and im- portance.Wagner analyses the classical problem of the electromotive force of galvanic cells involving phases of locally variable composition (46 pages). The fundamentals and applications of the useful rotating-disc electrode under conditions of non-turbulent flow are reviewed by Riddiford (70 pages). Graves, Hills and Inman contribute a present-state survey of electrode processes in molten salts (68 pages), and Hills and Ovenden discuss electrochemistry a t high pressure (64 pages), mostly in respect to applied pressure methods. Finally, Levich writes of the present state of the theory of oxidation - reduction in solution (bulk and electrode process) (124 pages), giving primary attention to the work of Dogonadze.All the chapters are well written, and the authors manage to handle their material in such a fashion as to appeal to both the newcomer to the field and the specialist. This is a valuable and welcome addition to the literature of electrochemistry. E. BISHOP MECHANISMS OF ELECTRON TRANSFER. By WARREN L. REYNOLDS and RUFUS W. LUMRYS Pp. viii + 175. New York: The Ronald Press Company. 1966. Price $7.00. In this valuable little monograph, the authors give an introduction to the principal mechanisms of electron transfer reactions, and discuss in detail and critically the experimental work on a limited number of systems, rather than attempting a more general and superficial coverage. This is a field of endeavour into which order and pattern have only recently been introduced, and this book offers a focus for future theoretical and experimental work.In this context electron transfer refers to the movement of an electron from iron(I1) to iron(II1) species and other similar processes, and not to the reaction mechanisms of permanganate oxidations and so on. The reactions considered are all of considerable analytical importance in several respects, and the study in depth offered here will be welcomed by those seeking to understand the processes they are using. E. BISHOP REINSTSTOFFPROBLEME. TAGUNGSBERICHT INTERNATIONALES SYMPOSIUM “REINSTSTOFFE IN vcTISSENSCHAFT UND TECHNIK” DRESDEN, 28 SEPTEMBER-2 OKTOBER 1965. Volumes I and 11. By E. REXER. Pp. xiv + 599 (Volume I) and xii + 707 (Volume 11). Berlin: Akademie-Verlag. 1966.Price DM 55; DM 55. Together with a third volume, “Realstruktur und Eigenschaften von Reinstoffen,” which is not yet to hand, these volumes contain the papers presented a t the second symposium on pure materials in research and technology, held in Dresden in September, 1965. The titles of the papers will be listed in Analytical Abstvacts. Volume I contains 46 papers on preparative and purification methods, both chemical and physical, including semi-scale, electrolytic, crystallisation, extraction, ion-exchange, chlorination, sublimation, distillation and zone-melting processes. Volume I1 contains 52 papers dealing with the determination of impurities in high purity materials grouped under the divisions of statistics, spectroscopy, mass spectrometry, activation, spectrophotometry, kinetics, electrochemistry and determination of gases in metals.Production is by offset litho from reduced typescript, which accounts for the size of the volumes, and is very well done. There is one Chinese contribution, and a large number of papers in Russian that are repeated in German translation, which adds to the size of the publication,662 BOOK REVIEWS [Analyst, Vol. 92 but will be found convenient by many readers. Purification of materials, the properties of really pure materials and the determination of trace impurities in such materials form an exacting branch of our science of rapidly increasing scope and importance. Potentially, therefore, these volumes could constitute a valuable and significant contribution to the literature.There are, indeed, several good and useful papers, but many papers are no more than brief and superficial reviews of particular fields lacking detail necessary to the implementation of the process discussed. Alongside the better papers, there are many, perhaps inevitably, that would never have been accepted by reputable journals. Reported discussion is sparse and seldom of much value. There is a publication delay of 18 months plus the period in advance of the meeting required for submission of papers. Can anything therefore be said in favour of this tardy, expensive, non-abstractable, closed form of publication as opposed to normal refereed publication in the open learned journals, whereby the better papers are strengthened and the remainder are filtered out ? Perhaps two minor factors lend some small justification in the present case: collection in one place of material that is not too well catered for as yet in reviews, and the heavy preponderance of Russian and Eastern European contributions that might otherwise appear in less readily accessible sources.One paper dealing with newer methods is 5 years behind the times. E. BISHOP ZWEITES KOLLOQUIUM UBER METALLKUNDLICHE ANALYSE MIT BESONUERER BERUCKSICHTIGUNG DER ELEKTRONENSTRAHL-MIKROANALYSE, WIEN, 20-22 OKTOBER 1965. Pp. iv + 248. 1966. Mikvochimica ActalSupplementum I. Price $6 12.00 ; to subscribers to Mikvochimica Ada, $10.00. This supplement to Mihvochimica A cta contains the papers originally presented at the 2nd Colloquium on Metallurgical Analysis, with special reference to the electron-probe microanalyser, held in Vienna in October, 1965.Twenty-four papers, all in German but each with a short summary in English and French, are published of which four, dealing with analysis of minerals, a correction procedure for X-ray fluorescence analysis and potentiostatic analysis seem to be outside the scope of the colloquium. Seven other papers deal with the application of the electron-probe micro- analyser to specific problems in which the analytical techniques and results form only a small, but nonetheless essential, part of the papers. The remaining papers cover specimen preparation techniques, instrumental modifications, measurement of instrumental parameters, “light” element detection and details of a correction procedure.From a mixed bag of papers such as is contained in this volume, anyone interested in electron- probe microanalysis is certain to learn something of value, if only that it is still possible to present papers a t conferences in which the application of results of relatively routine techniques are discussed in great detail. MAGNETIC SUSCEPTIBILITY. By L. N. MULAY. Pp. iv + 1751-1883. New York, London and 1967. Price 23s. This is a reprint, with additions and corrections, of Professor Mulay’s “Treatise on Analytical Chemistry,” Part 1, Volume 4. It is reproduced in its original pagination and is split into four sections. The second section deals with the theory of magnetic susceptibility in considerable detail. The third section on experimental work discusses all forms of measurement of magnetic susceptibility. The fourth section deals with analytical applications of magnetic susceptibility, and I am glad to see that Professor Mulay’s wife has persuaded him to add a very interesting section on biochemical applications. This is an excellent little book and is written by a known specialist in the field, who is also a man with a readable and easy style of writing. The book is packed with useful information and formulae and would appear to be a complete treatise on all aspects of magnetic susceptibility. Magnetic resonance is discussed as an offshoot of the main subject. There is good coverage of the subject both as a static (d.c.) and also as a complex (r.f.) effect. To conclude, I would say that this is an extremely clear discussion of the subject, possibly one of the best I have seen. There is a comprehensive list of references. The only adverse comment that one could make about this book is that there is no index, and that the soft cover tends to bend easily when in continual use. However, for its modest price I would have no hesitation in recommending it as it will be invaluable to any worker concerned with any aspect of magnetism. J. A. F. GIDLEY Sydney: Interscience Publishers, a division of John Wiley & Sons Inc. The first section, an Introduction, is extremely short, but precise and informative. H. M. ASSENHEIM

ISSN:0003-2654    

DOI:10.1039/AN967920657b

出版商:RSC    

年代:1967

数据来源: RSC