摘要:

SEPTEMBER, 1906. Vol. XXXI., NO. 366. THE ANALYST. PROCEEDINGS OF THE SOCIETY OF PUBLIC ANALYSTS. ON THE EXAMINATION OF OLIVE, LINSEED, AND OTHER OILS. BY R. T. THOMSON AND H. DUNLOP. ( R e a d at the Ilrieetirtg, J u n e 14, 1906.) HAVING seen reason, after careful investigation, to adopt Wijs' method of determining the iodine value of oils in place of the Hiibl method, we have made an examination of various oils of undoubted genuineness, and propose in the present paper to describe the results. As we have stated before, there is an element of uncertainty and unreliability in the Hub1 method, and in any event the Wijs and Hiibl results cannot be depended on as being interchangeable. It is therefore of importance that a fresh series of iodine values by the Wijs method should be constructed, and this we have done for several oils in the present paper, and' embodied the results, along with those of other constants, in Tables I.and II., p. 282. In the case of the olive oils prepared from the olives by ourselves, those extracted by carbon bisulphide were from the residue left after pressing out the bulk of the oil, and it will be observed that there is little difference between the two varieties. It is evident from these results that a genuine olive oil may vary in iodine value from 81 to 89, and may be regarded as such if the other constants are normal. There is a peculiarity with regard to the Mogador oil, which has an extremely high iodine value, while the refractorneter reading is lower than would be expected. We have found with regard to linseed and fish-liver oils that the iodine value and refractometer reading practically rise and fall simultaneously, but olive oil appears t o be quite erratic in this respect, as will be seen by an inspection of the tables.This difference is no doubt partly due to the influence of the free fatty acids, which, it has been stated, lower the refractive power; and this is undoubtedly the case, as will be seen from Table III., p. 283.282 THE ANALYST. TABLE I . Oils extracted by ourselves from the Seed o r Fruit, so that their Genuineness can be absolutely depended upon. Olive oil (Spanish, green, Olive oil (Spanish, green, Olive oil (Spanish, ripe, Olive oil (Spanish, ripe, Olive oil (Turkish, very Linseed oil (Rigi'FJeed) ' * Linseed oil (St. Peters- Linseed oil ( N o r t h Linseed oil (Calcutta) ...Linseed oil (River Plate) Ravison oil . . . ... Jsmba, oil ..- Rape oil (East India) ... Almond oil ... ... Gas tor oil ... ... by pressure) ... ... by CS,) ... ... by pressure) . . . ... by CS,) ... ... ripe) ... burg) ... American) . . . ... Iodine Value (Wijs). 83.20 83-20 88.95 88.15 89.1 205.4 200.0 194.6 188.6 185.5 118.1 98.3 104.5 98-1 85.6 Zeiss Refracto- nieter a t 25" C. 61-2 61.2 61.3 62.2 61.2 85.5 84.2 83.2 81.7 81.0 71.0 67.2 68.0 64-3 78.3 Saponifi- cation Value. Per Cent. 19.56 19.21 19.28 19.14 19.21 19.21 19.28 19.21 19.28 19.14 18.13 17.53 17.53 18-16 - Unsa- ponifiaktle Matter. Per Cent. 1.25 1.62 1.34 1.52 1.24 1.25 1.23 1.10 0.88 1-25 1.65 1.02 1.02 0.60 - TABLE 11. Oils obtained from Reliable Sources.Olive oil (Crete) . . . ... ,, (Italian) ... ,, (Sicilian) ... ,, (Levant) ... ,, (Algerian) ... ,, (Spanish) ... ,, (Mogador) ... Sunflower oil (Russian) (by Hubl's method) , . . Arachis oil ... 3 ) (Syrian) ... Poppy-seed oil ... ... ... Iodine Value (Wijs). 81-2 83.5 84.1 84.4 85-1 85.3 86.6 94.3 140.0 131.3 87.5 Zeiss Refracto- meter a t 25" C. 60.2 59.7 60.0 61.0 60.7 60.1 61.2 60.5 71.0 70.0 62.6 Saponifi- cation Value. Per Cent. 19.14 19.21 19.07 19.21 19.14 19.14 19.21 19.07 19-28 18.93 19.14 Specific Gravity, 60" F. Free Acid. Per Cent. Unsa- ponifiable Matter. Per Cent. Specific Gravity, 60" F. 0.9155 0.9157 0-9144 0.9159 0.9150 0.9145 0.9161 0.9150 0.9243 0.9220 0.9164 Free Acid. Per Cent. 9.40 16.61 11.50 9.32 5.62 11.76 7.27 24.72 1-62 1.21 -THE ANALYST. 283 TABLE 111.Showing the E f e c t of Free F a t t y Acids on the Refractive Power of Olive Oil. ___ ._ _ _ ~ _ _ Iodine value before removal of free acid ... ... Iodine value after removal of free acid Zeiss refractometer, 25" C. before removal of free acid Zeiss refractometer, 25" C. after removal of free acid Free oleic acid, per cent. before removal of free acid Free oleic acid, per cent. after removal of free acid ... Olive Oil (Mogador). 94.30 93.45 60.50 63.40 24.72 0.32 Olive Oil (I talian). 83.50 80-45 59.70 61-00 16-61 0-27 TABLE IV. Comparison of Iodine Value and Refractive Power of Linseed and certniiz Fish- liver Oils. Linseed oil I ) S kat e-liver (Riga) ... ... ... ... ... (St. Petersburg) ... ... ... ... (North America) , .. ... ... ... Linseed oil (Calcutta) ... ... ... ... ... Linseed oil (River Plate). .. ... ... ... ... Whiting-liver oil ... ... ... ... ... ... oil ... ... ... ... ... ... Haddock-liver oil ... ... ..- ... ,.. .., Iodine Value. 205.4 200.0 194.6 191.1 188.6 186.4 185.5 184.2 Zeiss Refraciometer a t 25" C. 85.5 84.2 83.2 82.5 81.7 81.0 81.0 81.0 The differences referred to cannot, however, be entirely explained by the influence .of the free acid, as will be apparent from an examination of the results in Tables I. and II., and especially of those of the two oils extracted from the same Spanish ripe olives, where the oil with the lower iodine value shows the higher refractive power, the free acids being practically the same. The different samples of linseed from which we prepared the oils were carefully ,examined, and any foreign seeds removed, so that only the genuine linseed wa6 employed.I t will be observed that the iodine value for the oil extracted from the Riga seed is, we believe, the highest on record, while that from the River Plate has an iodine value much higher than what was recorded by one of us some years since. There can be no doubt, however, that these high figures are due partly to the use of the Wijs in place of the Hub1 method, and where the former is employed any iodine value below 180 should lead to a more searching examination of the oil. ,4s regards the other oils of which the constants are included in the tables, it is scarcely necessary to make any remarks, except that the jamba oil cannot be .distinguished from rape oil by ordinary means, and that in some few cases the284 THE ANALYST, employment of the refractometer along with the iodine value may be useful, although the former is of no independent importance. In conclusion, we would draw particular attention to the peculiar similarity between various linseed oils and certain fish-liver oils as regards iodine value and refractive power, as shown in Table IV., p. 283. Of course, linseed oils have a, distinctly higher specific gravity than the fish-liver oils, but the saponification value and unsaponifiable matter are much the same in each.

ISSN:0003-2654    

DOI:10.1039/AN9063100281

出版商:RSC    

年代:1906

数据来源: RSC

摘要:

284 THE ANALYST, ON THE COMPOSITION AND VALUATION OF OILS USED FOR GAS-MAKING PURPOSES. BY RAYMOND Ross F.I.C. AND J. P. LEATHER. (Read at the Meeting June 14 1906.) A LARGE number of investigations have been made by numerous workers into the composition of the various petroleum oils found in certain parts of the world. These investigations have been largely confined to the fractions of low boiling-point and their principal aim has been the separation and isolation of definite compounds. The aim of our work has been primarily directed to the valuation of those oils which are used for gas-making purposes. Such oils consist generally of those portions of the crude oil which boil between 200' C. and 400" C. In certain states of the oil market even the refined petroleum burning oils are also used.From the results obtained by previous investigators-to which we shall refer later-we know that the various classes of hydrocarbons are found in varying pro-portions according to the origin of the oil. This being the case it is evident that to obtain a satisfactory knowledge of the gas-making properties of any oil it is necessary to ascertain the proportion of the different classes of hydrocarbons present in the oil and the gas-making properties of each class. The presence of the following classes of compounds in given petroleum oils has been proved by various workers-notably Markownikoff Zelinsky Aschan, Schorlemmer Engler Schutzenberger Maybery and others : Paraffins. Olefines. Aromatic hydrocarbons. Naphthenes. In this last term are included saturated and unsaturated hydrogenated deriva-tives of both benzene and naphthalene and their homologues.Some preliniinarg work which we undertook-the result of which was communicated to the Society of Chemical Industry (May 1902)-1ed US to think that the determination of certain chemical and physical properties of an oil might enable a correct judgment to b THE ANALYST. 285 formed of the nature and composition of any gas-oil. For this purpose it was necessary that the physical properties and the value for gas-making properties of each class of hydrocarbons should be separately determined. The present communication sets forth the progress that we have so far made in this direction and also the results obtained from the examination of a large number of gas oils.Although owing to the difficulties inherent to such a research our progress is more limited than we had hoped we trust that our results will be found to be both of theoretical interest and practical utility. Before proceeding further it will perhaps be best to recapitulate the methods which we use for the valuation of an oil and which are substantially those men-tioned in our previous paper. For the purpose of gasifying the oil we make use of a retort about 9 inches long by 52 inches wide and 42- inches in height. The retort carries an electrical pyrometer and two tubes-one for introducing the oil, going only a short distance into the retort and the other for the exit of the gas, being carried the whole length of the retort. The oil is fed in from a burette and the gas after passing through a tar-bottle, is collected in a holder measured and analysed.After the retort has been brought So the required temperature the gas-supply is turned off and 15 C.C. of oil run in during a period of about three minutes. Experience has shown us that if these directions are followed there is practically no variation in the temperature of the retort during the period of gasification. The size of the retort as well as the rate of flow of the oil are important factors as if the time of contact is altered the quantity and quality of the resultant gas are affected. The resultant gas is measured and then the amount of hydrocarbons absorbed by fuming sulphuric acid is ascertained in a Hempel burette and this figure is given in all our results as (' hydrocarbons." The number of C.C.of gas at N.P.T. per C.C. of oil (at 15" C.) multiplied by the percentage of hydrocarbons ascertained as above gives a number which we have called the '' valuation figure." The temperatures which we have selected for cracking the oils are those at or between which we have after many experiments, invariably obtained the highest valuation figure. In addition to the foregoing cracking test we make a distillation test on the following lines 250 C.C. of the oil are distilled and the fractions are separated at intervals of 20" C. in such a way as to have an even number for the second digit. The quantity of each fraction is measured and its specific gravity and refractive index determined. The specific refraction is then calculated.Before proceeding further it will perhaps be best to give a rksumh of the results which we have obtained by the examination of a number of different oils from various parts of the world. This is heated in a mufie furnace 240" C. t o 260" C. ____ .___ 280" C. to 300" C. 300" C. to 320" C. 1 200" c. t o 220" c. -~ N - I I ND. yj--I ~ 1.4570 0-556 0 00141 0.001 1.46551 0.555 i I 1.4711 0'552 I I 1 ND. I -1- I I 1'4449 0'558 - 1 -I 1.4697 0.555 I ' 1.4659 0'552 1.4679 0-549 1.4775 0'548 0'0028 0'004 1'4709 0.553 1'4796 0'656 0'0064 0,002 - i -SP. Or. N - 1 ND. 7 -1.4734 0.555 0.0007 0*001 L=18161 0'555 - 1 - I L'4S29 0'549 1'5042 0.551 1.0025 0.002 1.5040 0 555 I 1'4959 0'557 1.0099 0.002 1'4S95 0559 i 1'4947 0'5i4 1'0015 0'003 1 I - I -'4651 0561 1.00231 0 001 I SP.Gr. __ 0.797 -0.829 0'844 0'852 0.873 0'014 0'861 0.861 0'011 -i l PENNSYLVANIAN : KANSAS : 0'804 I1'4475J 0.556 RUSSIAN REFINED : 0'825 11.46471 0.551 RUSSIAN : - 1 - 1 -TEXAS : 0'844 1'4607 0'546 . - ~0*0005j 0'001 CALIFORNIAN : 0'822 I 1.4554 I 0'554 ROUMANIAN : 0'829 1*4616/ 0556 . 0'015 10.0080 0.004 GALICIAN : - 1 - 1 -GROSNY : , BORNEO : ' O'S61 I1'4827l 0.560 SCOTCH : - _ _ r . - l - / -0.841 ~ 1.4681' 0-55E - I 0.00031 0*001 0'860 ,I-4780 0.556 , I I I - - I - ' I 0371 11.47941 0'550 0.851 0 001 0967 -0379 0'9t.5 0'003 0'908 O'S90 0'018 O'S76 0.894 0-007 I-O'S64 3 '003 0'821 0.002 0.838 0.853 0.833 1'4635 0'55f - 0'0004 0'001 j I 0 S50 11.47231 0'55 ' 1 ! - ! - I -0 862 ! 1.4749 0'551 I 1 - I - ! _ 0'855 1-4705 0551 1 ; 0-895 11.49181 0'529 0'0022 0,003 0'906 11'4974 0'549 0'895 1.4989 0'557 l 1 0'883 1'4920 0'557 0'584 1'4849 0.348 0.003 0'0019 0'004 0.003 0'880 0.882 3'012 3'856 3.876 1-007 3'936 1.844 1'004 0.836 I1.4628' 0.553 I 1 1'4873 0'554 1'4914 0.557 0.0057 0.009 1.4722 0.557 1'4S47 0'553 0'0013 0'003 1.5242 0.560 1.4732 0'560 0'00231 0'001 I ( 1 1 ' 0'847 1.4709' 0'556 0,009 0'0061 0'002 0 017 0.865 0.886 0'007 -0.553 0.004 -0 0097 0'002 1'4S30 0'558 I 1-4886 0'552 0'0028 0'001 i - I -I 1*47iB 0'560 0'0027 0-001 ~ ""-I - ""-- I -1 -0'860 0'018 0.920 I I 0'857 1.4ilCh 0'550 0*006 0'0014 0.002 1~ 0'900 1'5043 0'560 1 -I -- 1 -I 0'833 1.4673 0.330 0.007 0.0035; 0'001 N - 1 Nn=Refmctive index for Sodiiini light.=specific refractioa Lincs i~nrlred 1. give tlic cxtrem Name of Oil _ ~ _ _ _ -Pennsylvanian Kansas . Russian . Russian refined Texas . Californian Roumanian Galician . Grosny . Borneo . Scotch . .-.{ .{ . . *{ .{ .I .{ 1 *-I . .{ .I .{ THE ANALYST. AVERAGES OF GASIFICATION RESULTS. Tnipcrature of Cracking. 1260" F. 1400' F. 1510' F. 1260' F. 1400' F. 1260' F. 1510" F. 1260" F. 1510' F. 1700" F. 1130" F. 1260' F. 1400' F. 1450" F. 1510' F.1130" F. 1260' F. 1400" F. 1130' F. 1260" F. 1400" F. 1450" F. 1260" F. 1130' F. 1260" F. 1400" F. 1260" F. 1510' F. 1640" F. 1130' F. 1260" F, 1450" F. - __ C.C. of Gas N.T.P. per c. of Oil. 44.5 529-9 563 438.9 483.6 465.7 556 429 518 550 325 388.3 461.8 547*7 508.8 3'70.8 5299 573.9 301.3 388.8 459.7 557.3 452.8 341.8 421-9 501.6 301 472 . 495 286-5 426.4 491.5 Hydrocarbons per Cent. -35.8 30.1 26.6 33.6 28.4 34.2 22.8 31.8 28.4 21.5 30.1 29.8 25.3 18.6 21.1 29.8 26.6 25-4 40.5 33.3 28.6 20.2 35.5 34.9 34.6 25.8 26-8 17 15 40.3 34 -2 26.1 287 Valuation Figure. 15,944 15,950 14,967 14,747 13,706 15,927 12,677 13,642 14,711 11,825 9,769 11,490 11,697 10,187 10,741 11,050 14,095 14,577 12,302 12,895 13,147 11,257 16,074 11,925 14,489 12,860 8,067 8,024 7,425 11,548 14,620 12,790 As the worst results which we have obtained were got from Borneo oil we determined to make a special examination of this oil.We commenced work on the lower boiling fractions with an attempt to obtain some definite compound by means of repeated fractional distillations but without success. We therefore had recourse to chemical means and to this end treated that fraction of the oil which boiled in the neighbourhood of 200' C. with an excess of fuming nitric acid for a period of some days with constant mechanical stirring, adding the nitric acid gradually and warming when the violence of the reaction had abated.At the end of the time the mixture separated into three layers-viz. unacted on oil a wax-like substance and nitric acid. The residual oil was treated with sulphuric acid and then heated with fuming sulphuric acid (50 per cent. SO,) sever 288 THE ANALYST. times. I t has been shown that fuming nitric acid acts in the following manner (Francis and James Chzem. Xoc. Jown. 1898)-viz. it readily attacks aromatic compounds methyl derivatives of polymethylene compounds and the iso-paraffins. All these compounds are characterized by the presence of a CH group. Consequently in the fraction experimented upon only normal paraffins and decahydronaphthalene could be present in any quantity after the double treatment.An analysis of the remaining oil gave the following figures : Per Cent. ::::; 1 Specific gravity of oil 0-821 15"/15" This analysis shows less hydrogen than corresponds to CnHen and it therefore approximates more nearly to decahydronaphthalene than to a paraffin, The oil was next boiled with excess of bromine in carbon tetrachloride with a reflux condenser for many hours in the hope that some substitution might take place in the paraffins. Hydrobromic acid was given off and after distilling off the carbon tetrachloride the residue was boiled with caustic soda to decompose the bromine compounds and thus leave unsaturated products. After washing the oil was again treated with fuming sulphuric acid and warmed. After separation washing and drying the oil gave on analysis : Theory for CI,Hl8.C 86.77 . . 86.96 H 13.24 . . 13.04 Its specific gravity was 0,843 at 15" C. The N 1.4507. Boiling-point 169.5" C. Molecular weight determination by Beckmann's boiling - point method 1.33.4 (theory 138). According to Beilstein the gravity is 0.847 at 15" C. and the boiling-point 173" to 180" C. The substance obtained which was probably fairly pure deca-hydronaphthalene was then cracked in a similar manner to the gas oils at 1260" F., and gave results as below : 434.1 c,c. of gas at N.T.P. per'c.c. of oil containing 26.2 per cent. of hydrocarbons soluble in fuming sulphuric acid giving a valuation figure of 11,373. The yellow wax-like substance obtained by nitrification was washed separated, and dissolved in absolute alcohol.After many attempts two batches of crystals were obtained in which the carbon was estimated by moist combustion with chromic acid. Several ordinary combustions were spoilt by explosions even when air was used and great care exercised. The gas from the moist combustion mas led through a combustion-tube containing copper oxide and reduced copper. The first batch of crystals gave as a result of three closely agreeing analyses carbon 54.28 per cent., and the nitrogen as determined by the modified Kjeldahl method was 12.7 per cent. These figures point to a dinitrotetrahydronaphthalene for which the theory is C=54.04 per cent. and N=12-61 per cent. To verify this suggestion we treated about 70 grams of the nitro compound with 300 grams of tin and 1 litre of hydro-chloric acid heated under a reflux condenser until the tin was dissolved; we then added an excess of strong caustic soda.This was washed with water and finally distilled i7z wacuo. A thick pitchy mass rose to the top THE ANALYST+ 289 To the distillate hydrochloric acid was added and after standing crystals were obtained which on being recrystallized from alcohol were nearly colourless and gave on analysis-Theory for C,,H,, Per Cent. (NH,HCI),. C 50-7 . . . . C 51.1 H 7.4 . . . . H 6-8 N 11.8 . . . N 11.9 C1 29.9 (calculated from nitrogen) C1 30.2 99.8 100*0 . -The agreement with theory is sufficiently close to identify this compound as diamidotetrahydronaphthalene hydrochloride. From some uncrystallized nitro com-pound we obtained by the above methods an amido compound which went rapidly black and was probably an isomer of the first but was not analysed.The foregoing investigations having dtrnonstrated the presence of decahydronaphthalene and tetrahydronaphthalene in the fractions experimented upon we next attempted to prepare these substances synthetically. Tetrahydronaphthalene was prepared by the action of sodium on a solution of naphthalene in amyl alcohol (according to the method of Bamberger and Kitschelt), the sodium being added gradually to the boiling solution. The oil obtained was separated dried and distilled. After many repetitions we finally obtained about 200 C.C. of distillate boiling between 203" C. and 206" C. This was cooled to freeze out any naphthalene and redistilled.The distillate between 203" C. and 206°C. gave the following constants Specific gravity 0.977 at 15" ND= 1.5712 I-__ = 0.584. 205" C. with the following results : ND-1 d Bamberger and Kitschelt give the gravity as 0.978 and the boiling-point at The tetrahydronaphthalene obtained as above was next gasified at 1,260" F. C.C. of gas per C.C. of oil _ . . . 134.5 Hydrocarbons . . . . . 13.6 Valuation figure . . 1,829 . . . The significance of these results will be referred to later. From the tetrahydro-naphthalene we attempted to prepare decahydronaphthalene by passing its vapour together with hydrogen over reduced nickel but without success although by this method we had previously obtained a good yield of hexamethylene from benzene without difficulty.We finally prepared some decahydronaphthalene by treating tetrahydronaphthalene with hydriodic acid and phosphorus in sealed tubes. Eleven tubes each containing 10 C.C. of tetrahydronaphthalene 0.5 gram of phosphorus, and 25 C.C. of hydriodic acid saturated at 0" C. were sealed off and heated in a bomb furnace. As they gave a very poor yield the remaining seven tubes were heated only to 210° C. and the time was extended to four days. From these tubes we obtained 14 C.C. of a liquid boiling between 170" C. and 178' C. This was redistilled the greater portion coming over between 170' C. and 173' C. This fraction had the following constants The first four were heated to 260" C. for thirty-six hours 290 THE ANALYST. Specific gravity = 0.8426 at 15" C. . N . . = 1.4486 at 20" C.C . 86.91 H . 12-90 99.81 The gravity and boiling-point are thus = 0.532 Theory-for C,,H,, 86-96 13.04 100~00 very slightly lower than those given by Wreden and are in close agreement with the decahydronaphthalene obtained by US from Borneo oil. According to Engler when petroleum oils are dissolved in a mixture of alcohol and ether (equal parts) and cooled the paraffins solidify out and may thus be separated and estimated. Five representative oils were fractionated so as to obtain those portions which boiled between 300" C. and 350" C. with the exception of Borneo of which the portion boiling between 280" C. and 340" C. was retained. Each of these fractions was then mixed with about four times its bulk of alcohol and ether and cooled to - 18" C.by means of liquid ammonia. I n the case of the American and Roumanian oils solids were obtained which were separated off and pressed between blotting-paper. The Russian Texas and Borneo oils separated into two portions and in each case the portion insoluble in the alcohol-ether mixture was separated off. It was naturally thought that these portions would principally consist of paraffins and olefines and they were cracked in the usual manner. The solid from the Roumanian oil had a gravity of 0.839 at 42" C. and an iodine absorption (Hubl) at '7.09 per cent. As this evidently contained some olefine it was treated with Nordhausen and after treatment the gravity was 0.857 at 15" C. and the iodine absorption was nil. The refractive index at 27' C.was 1.4709 therefore = 0.549. These figures corrected to gravity at 15" C. and N at 20" C. give N - 1 d N - 1 d =0-553. The American solid portion had a gravity of 0.849 at 15' C. and N at 20" C. was therefore 1.4734 = 0.557. d The iodine absorption was 17.2 per cent. The following table gives the results obtained on gasification of the above : C.C. of Gas Per Cent. Valuation per C.C. of Oil. Hydrocarbons. Figure. Roumanian . 465.4 35.4 16,475 American . 431.2 40 -0 17,248 Texas . . 430.2 27.2 11,701 Borneo . . 342.7 26.4 9,047 Russian . 425.3 38-9 16,544 The insoluble portion of the Borneo oil had a gravity of 0.9286 at 15" C THE ANALYST. 291 According to Kraft the gravity of the higher paraffins at their melting-points approximates to 0.777.We prepared undecane by Krafft's method from oil of rue. The oil was obtained from the London Essence Company and our best thanks are due to Mr. Burgess, their chief chemist for the trouble he took to procure us oil rich in ketones and for information as to the best method to prepare them. His method with very slight variations was used and was carried out as follows 240 C.C. of the oil of rue was mixed with 1 litre of a 40 per cent. solution of sodium metabisulphite. The mixture was kept at 70" C. on a water-bath for five hours with vigorous mechanical stirring all the time. Eight lots of 4 grams each of sodium carbonate were added at intervals of fifteen minutes. At the end of the five hours the mass was allowed to stand overnight and the liquid portion poured off.The crystalline residue was washed three times with ether cooled to 0" C. and then drained and pressed between blotting-paper. To the residue an equal weight of sodium carbonate and enough water to cover the mass were added. The mixture was heated on a water-bath under a reflux condenser for some hours. The liberated ketone was separated off and the mass extracted with ether and the ethereal extract added to the ketone. The ether was distilled off and the ketone fractionated. The portion boiling between 223" C. and 225" C. had a specific gravity of 0.8266 at 20" C. and N 1.4271. Theory for ND=1*4231 and according to Beilstein the gravity is 0.8268 at 20-5" C. Several lots of methylnonylketone were prepared in the above manner and the yield was in some cases as high as 50 per cent.of the oil of rue taken. Some of the ketone thus obtained was mixed with an equal bulk of chloro-form and one-third more than the calculated weight of phosphorus pentachloride added gradually to the liquid through a reflux condenser. When all the phosphorus pentachloride had been added the contents of the flask were heated on a water-bath for a short time and then cooled and poured into water. The chloride and chloroform were separated off and the chloroform dissipated on the water-bath; 12 C.C. of the undecylene chloride were then treated with 25 C.C. of hydriodic acid (2.0 specific gravity) and a little phosphorus in sealed tubes at 210" C. for forty-eight hours. The contents of the tubes were poured into sodium thiosulphate solution and the oil separated and distilled, It was redistilled and the portion boiling between 193" C.and 195O C. (except 754 mm.) gave the following constants : The greater part came over between 190" C. and 200" C. Specific gravity - 0-7466 at 15'/15'-N 1.41817 N 1.41620 According to Krafft the density is 0.7448 15'/4" and the boiling-point 194.5" at The calculated refractive index according to Bruhl's formula is Na - 1-41254. 760 mm 292 THE ANALYST. The above substance is therefore fairly pure undecane. The undecane was next cracked in the usual manner with the following results : At 1260" I?. At 1400" F. C.C. of gas at N.T.P. per C.C. of oil . 492.4 544.4 Hydrocarbons . . . . 36.4% 33 ~80/~ Valuation figure . . . 17,923 18,400 As we were unable to separate olefines from the petroleum oil we give the preparation and the results obtained from an olefine prepared from oil of rue.Methylnonylketone prepared in the manner already described was converted into the carbinol by mixing it with amyl-alcohol and adding a considerable excess of sodium to the boiling mixture using a reflux condenser. This operation occupied about three days. When the reaction was completed water was added and the methylnonylcarbinol and amyl-alcohol separated. The amyl-alcohol was distilled off and the carbinol remaining was then very gradually run on to an excess of phosphorus pentoxide in a flask provided with a reflux condenser and heated on a water-bath. The resultant mass was next extracted several times with ether and after distilling off the ether the oil.obtained was fractionated in a four-bulb Young's dephlegmator ; the fraction boiling 191' C. to 193" C. gave the following constants : . Specific gravity 0.7735 at 15'/15" N D 1 -43 3 25 __ 0.560 N a 1.43148 8 0.558 N - 1 d NP 1 -44198 7 9 0.571 N -1 d The -?-.- calculated according to Bruhl's figures is 0,558. According to different authorities the boiling-point of undecylene varies from 192" C. to 196' C. and the gravities from 0-790 to 0.8398 at 0" C. The density calculated from the formula proposed by Isidor Traube (Bey. 1895, xxviii. 2924) is 0-765 k 0.02 which is in close agreement with our results. A Hiibl iodine absorption of the olefine gave 164.4 per cent iodine absorbed the theory for undecylene being 164.2 per cent.This oil was therefore fairly pure undecylene. The undecylene obtained was next gasified in the usual manner with the following results, 15 C.C. being used for each experiment : At 1260" F. A t 1400" 3'. C.C. of gas at N.T.P. per C.C. of oil . 493.6 550.4 Hydrocarbons . . . . 30*80/6 29.0% Valuation figure . 15,202 15,961 Benzene vapours . . , . 2.4 Heavy hydrocarbons . . . . 28.4 Methane . . . . \ 45.2 Hydrogen . . . . . 23-9 . . The analysis of the gas obtained at 1260" F. was as under: Per Cent. 99. THE ANALYST. 293 I n our first attempt to prepare undecylene we used amyl-alcohol and sodium amalgam for the preparation of the carbinol passing in a stream of carbon dioxide all the time. The resultant oil was treated with phosphorus pentoxide in the manner before described but the temperature was kept much higher (about 200' Cl.) by means of an oil-bath.Very little undecylene was obtained but a series of fractions of the following composition : B. P. Carbon. Hydrogen. 240" C. to 280" C. . . 86.0 13.6 280" C. to 350" C. . . 86.85 13.03 350" C. to 370" C. . . 86.55 13.17 370" C. to 375" C. . . 83.05 13.57 Although these fractions were further examined no very definite conclusions could be drawn as to their constitution. The last compound is possibly a ketone of approximately the formula C32H640 or C32H,,0. In order to institute a comparison between our method of valuation by means of cracking on the small scale and the results obtainable in practical working on the large scale we append a series of tests carried out on the large scale with certain oils.These oils were used in a carburetted water-gas plant erected by the Economical Gas Apparatus Construction Company. I n every case all possible precautions were taken to obtain the best results, which were as follows : Pennsylvanian Oil. Laboratory valuation figure 16,000. Quantity of gas made 391,000 cubic feet. Amount of oil used 969 gallons = 247 gallons per 1,000 cubic feet. Average candle-power 22.12 = 8.9 candles per gallon per 1,000 cubic feet. Quantity of coke used in generator 13,260 pounds=33-9 pounds per 1,000 cubic feet. Russian. Oil. Laboratory valuation figure 15,927. Quantity of gas made 1,186,000 cubic feet. Quantity of oil used 3,078 gallons = 2.59 gallons per 1,000 cubic feet.Average candle-power 22.61 = 8-73 candles per gallon per 1,000 cubic feet. Quantity of coke used in generator 38,556 pounds = 32-5 pounds per 1,000 cubic feet. Texas Oil. Laboratory valuation figure 11,697. Quantity of gas made 349,000 cubic feet. Amount of oil used 1,144 gdlons=3*277 gallons per 1,000 cubic feet. Average candle-power 20.51 = 6.2 candles per gallon per 1,000 cubic feet. Quantity of coke used in generator 12,240 pounds = 35.0'7 pounds per 1,000 cubic feet 294 THE ANALYST. Borneo Oil. Laboratory valuation figure 8,024. Quantity of gas made 5,410,000 cubic feet. Amount of oil used 19,645 gallons = 3.63 gallons per 1,000 cubic feet. Average candle-power 17-03 = 4.69 candles per gallon per 1,000 cubic feet. Amount of coke used in generator 178,500 pounds = 33 pounds per 1,000 cubic Taking American oil as a standard the following comparisons may be instituted : feet.Laboratory Test. Works Test. . 100.0 American oil . 100.0 Russian oil . . . 99.5 98.1 Texas oil . . . 73.1 70.3 Borneo oil . . . 50.1 52- 7 From the above it is evident that our method of valuation yields approximately correct results. Having now completed the experimental portion of our paper we will proceed to discuss the conclusions which we think may fairly be drawn from the foregoing result a. A consideration of the figures in the distillation test tables makes it evident that, comparing fractions of the same boiling-point the lower the gravity and refractive index, the better the oil for gas-making purposes. The following table gives a summary of the constants obtained for the different ' Boiling- Name.i point, I Undecane . . . ' 194" Undecylene . . 193' . Decahydronaphthalene . i 172" Hexahydrocymene (accord- , ~ Tetrahydronaphthalene . 1 205" to Markownikoff) ._. 1 161" Specific Gravity. 0.746 0-773 0.843 0.977 0.783 ND 1.4182 1.4332 1.4507 1.5712 1.4323 0.560 0-5 60 0,534 0-584 0.552 __ __--Valuation Pigure. 18,400 15,961 11,373 1,829 -From this table it will be seen that although the boiling-points are not far apart the paraffin has the lowest gravity the olefine decahydronaphthalene and tetrahydronaphthalene increase in gravity in the order named. The same also holds good for the refractive index while on the contrary the value for gas-making pur-poses decreases in the same order.A further class of bodies which we have not yet succeeded in preparing synthetically consist of such compounds as hexahydro-cymene. Such cycloparaffins partake of the nature of both open chain and ring compounds and their value for gas-making purposes will no doubt depend on the relative number of carbon atoms contained in the chain and ring respectively. The presence of such compounds is indicated by the high gravity of the soli THE ANALYST* 295 paraffins separated from American and Roumanian oils whilst the specific refraction is only slightly lower than that of normal paraffins; Generally we think we are justified in concluding from our results that-1. The open chain compounds have the best value for gas-making purposes.2. The presence of double bonds in the chain slightly decreases the value. 3. The presence of one or more rings diminishes the value considerably. 4. The more fully hydrogenated the ring the better its value as compared with 5. Benzene rings have practically no value for cracking purposes. Next considering the relation of the gravity to the refractive index as expressed by the specific refraction there are some important and interesting deductions to be other ring compounds. made. The open chain compounds both paraffin and olefine have a specific refraction of about 0.555 to 0.560. The presence of a hexamethylene ring lowers the specific refraction and a saturated double ring reduces it still further. On the other hand, the specific refraction is raised considerably by the presence of an unsaturated ring, as in the case of tetrahydronaphthalene.Having deduced these conclusions from an examination of the pure hydrocarbons, it will be well to consider their bearing on the constants given by some of the various gas oils examined. For this purpose it will be well to consider the oils from the different regions separately and in most cases for simplicity to compare the fractions boiling between 280' C. and 300" C. as these are contained in all the oils examined. I n Pennsylvanian oil the gravity and refractive index of this fraction are lower than those of any of the other oils examined. The specific refraction (0.556) approaches that of a paraffin. This would indicate that the fraction contained a large proportion of paraffins and olefines.This opinion is modifid by the fact that its gravity (0*833) and that of the solid portion obtained on freezing out from ether-alcohol solution (0.849) are too high in relation to the melting-point and boiling-point to consist entirely of these substances. They would however quite agree with a mixture of paraffins olefines and what we may term paraffinoid bodies-Le. com-pounds containing one or more long open chains together with a hexamethylene ring. Applying the same process of reasoning to the case of Russian oil we should conclude that this oil consists principally of paraffinoid substances as though the gravity (0.862) is somewhat higher than in the case of American the specific refrac-tion (0.551) is rather lower.This conclusion is supported by the fact that it is difficult to freeze out any solid substance from the ether-alcohol solution and that the figures obtained could not agree with any other conclusion or with the high valuation figure obtained. I n the case of Texas oil the gravity is 0.895 and is higher than that of either Pennsylvanian or Russian and the specific refraction is still further lowered to 0-549. This oil therefore probably contains considerable quantities of complex ring com-pounds fully hydrogenated but not tending to be paraffinoid in their nature. This is distinctly confirmed by the valuation figure. The Roumanian oils vary considerably but considering the average gravity (Om882) and the specific refraction (0-557) of the fraction previously indicated we think tha 296 THE ANALYST.they must contain a considerable quantity of unsaturated ring compounds as the gravity precludes any great amount of compounds with long open chains and the high specific refraction is inconsistent with a preponderance of fully saturated ring compounds. Some Roumanian oils however have a composition differing from the average given and fall between Pennsylvanian and Russian oils in their properties. The Borneo oil examined by us differs from any of the preceding oils in that it contains a larger amount of unsaturated and partially hydrogenated ring compounds. This is shown by its very high gravity (0.936) in the specified fraction together with ts high specific refraction (0.560). This conclusion is also entirely in accordance with the valuation figure.Of the other oils examined the Kansas with a gravity of 0.850 and a specific refraction of 0.555 is somewhat inferior to Pennsylvanian for gas-making purposes, and in composition it is between Pennsylvanian and Texas but more nearly approaches the former. Californian probably contains a fair proportion of paraffins and paraffinoid bodies, but in addition to these its constants indicate a certain amount of incompletely saturated compounds particularly in the higher fractions. The only Galician oil we have examined was very similar in gravity to Russian oil but had a higher specific refraction thus indicating a somewhat higher proportion of open chain compounds but less than in the case of Pennsylvanian. The Grosny oils approach the Russian in character but are somewhat inferior, probably due to the presence of more paraffinoid bodies and fewer true paraffins.The Scotch gas oils are of course not true petroleum oils. From their low gravity together with the specific refraction of 0.560 one would almost expect a better valuation figure than that obtained. By the method of formation destructive distillation one would naturally expect a considerable proportion of olefines and also some substances containing benzene rings. These latter are probably paraffinoid in their nature as otherwise the gravity would be much higher. We have not however, had time to devote the same attention to Scotch oils M to the others and hope at some future time to investigate them further. We recognise that none of our deductions as to the composition of the various oils can be taken too dogmatically as the number of possible hydrocarbons is so great while the constants from which the deductions have been drawn are few in number.Considering the present state of our knowledge of the higher hydro-carbons we think that the method of reasoning adopted will be found to give a useful index as to the relative value of oils used for gas-making purposes. DISCUSSION. Mr. L. nIYDDELToN NASEI asked whether in addition to the valuation of the oils from the volumes of gas and the proportions of hydrocarbons yielded any photo-metric tests of the oil-gas had been made. He had at one time had a good deal to do with the manufacture of oils of this kind and had always regarded Borneo oil as the lowest in value for gas-making purposes his experience thus agreeing with that of the authors in this respect THE ANALYST.297 Mr. Ross said that the carburetted water-gas in the works tests had been examined photometrically but not the oil-gas made in the laboratory. Some other kinds of Borneo oil and the higher fractions of certain Borneo wax oils gave con-siderably higher valuation results. Some of them contained solid paraffins and so were of low specific gravity. Mr. W. J. ATKINSON BUTTERFIELD thought that the laboratory figures were not quite on all-fours with the works results because the former were arrived at without any knowledge of the nature of the hydrocarbons in the gas. Very often the gas containing 20 per cent. of hydrocarbons from one oil would have a very much higher illuminating value than the gas containing 20 per cent.of hydrocarbons estimated in the same way from another oil owing to the different nature of the hydrocarbons in the two cases. The method proposed by the authors therefore could not be expected to afford an absolute criterion of the gas-making value of an oil. Never-theless it was a very useful auxiliary test and he had himself used it for some time in a very similar €orm to that now described. He thought it would be an improve-ment to make the carbonizing apparatus rather larger and to use a somewhat larger gas-holder so that a portion of the gas might be available for photometric and even for calorific tests. These tests should preferably be made on a mixture of the oil-gas with coal-gas because all kinds of oil-gas had not the same power of enriching coal-gas owing to the differences which occurred in the hydrocarbons according to the temperature at which the gas was made and the kind of oil used.The authors had remarked that benzene rings were of no value and perhaps in one sense that was the case; but as a matter of fact carburetted water-gas owed its illuminating power to hydrocarbons which were roughly speaking those contained in 90 per cent. commercial benzol. It was true that benzol and hydrocarbons containing benzene rings were useless for cracking but it was not altogether useless to make benzene and use the coal-gas as a carrier of it for in that way a greater illuminating duty was obtained from the oil than by converting it wholly into a permanent gas, while the mixture of coal-gas and benzene vapour was sufficiently permanent for transmission to the consumer so far as all ordinary degrees of enrichment of coal-gas were concerned.Mr. LEATHER said that theoretically Mr. Butterfield was no doubt quite right in saying that the hydrocarbons absorbed by fuming sulphuric acid had somewhat different illuminating values but from the practical standpoint of the working of the oils in carburetted water-gas it was found that the proportion of hydrocarbons absorbed corresponded very fairly with the photometrically determined illuminating power of the gas,'while the working tests showed that-in the case at any rate of the four oils they had tried-the laboratory results corresponded closely enough with practical values for the ordinary valuation of an oil.When they said that the benzene ring was of no value they did not refer to benzene itself there being no actual benzene in the oils they used. What they had found was that in the case of a hydrocarbon like tetrahydronaphthalene containing one saturated or practically saturated benzene ring a low valuation figure was obtained. Mr; W; Irwin on cracking some portions of ordinary coal-tar oil (which was practically speaking, creosote oil consisting chiefly of hydrocarbons containing benzene rings) had foun 298 THE ANALYST. these to show such poor values as to be really useless for gas-making. As to the illuminating value of benzene they agreed but if there were more than a certain quantity of benzene in the oil the greater part of it would go into the tar instead of into the gas.As long as the gas had to come into contact with tar the quantity of benzene it would carry was strictly limited; With regard to Mr. Butterfield's sug-gestion that they should use a larger laboratory apparatus and so obtain enough gas for a photometric test they would need for this 10 cubic feet of gas as an tbsolute minimum and it was questionable whether on such a scale the cracking temperature could be exactly maintained. I n the apparatus they used at present the cracking temperature was absolute-Le. the whole of the oil was exposed and cracked at an exact temperature within 10 degrees. The retort was heated in the muffle up to the temperature at which cracking was commenced (say about 1260" F.) the gaL a was turned off and the oil run in.The experiment took from three to three and a half minutes and during that time the temperature never varied more than 10 degrees, because the fireclay casing of the retort being slightly hotter than the retort itself, gave up heat to the latter at about the same rate at which the heat was taken up in cracking. This was a rather important point and anyone repeating their experiments would have to use a retort of the same size and apparatus of a similar description, and to see that the time taken for running the oil in was the same or at any rate, to see that the relationship between the various factors was such that the cracking temperature was constant. On a larger scale it would not be possible to insure this.Mr. W. J. ATKINSON BUTTERFIELD agreed that it was advantageous to work at 8 uniform temperature but thought that photometric tests might be made as he had sug-gested by mixing the oil-gas with coal-gas. Tests made in that way too would more nearly represent practical conditions. As to the comparison between the laboratory and works tests the works values for two of the petroleum oils seemed to him extremely low. He had generally found it to be quite as high as or even slightly higher than that of Russian or Pennsyl-vanian oil. He quite agreed with Mr. Leather's remarks with reference to tar having only a low value for gas-making. Mr. J. H. B. JENKINS said that a good deal of oil-gas was made by railway companies and used for illuminating purposes after compression. The value of an oil wbs usually judged by multiplying the candle-power into the number of cubic feet of gas made from a given quantity of oil and if such a figure could either now or at some future time be included in the authors' results it would be very useful inas-much as it would enable a direct comparison to be made between their laboratory valuations and the methods of valuation ordinarily adopted in practice. Mr. Ross said that they could not do exactly as Mr. Jenkins suggested but the factor he had mentioned was given in their works tests for the carburetted water-gas. He might mention that the exact composition of the oil-gas was not at present known but that they had reason to believe that certain bodies occurred in it the presence of which perhaps had not been anticipated. Amongst these was un-doubtedly a considerable quantity of cyclo-pentadiene. This they had succeeded in separating. The value given for the Scotch oil aleo seemed low

ISSN:0003-2654    

DOI:10.1039/AN9063100284

出版商:RSC    

年代:1906

数据来源: RSC

摘要:

THE ANALYST. ABSTRACTS OF PAPERS PUBLISHED IN OTHER 299 JOURNALS. FOODS AND DRUGS ANALYSIS. Methylene Blue as a Test for the Freshness of Milk. P. T. Muller. {Archiv Hygiene, lvi., 108; through Pharm. Journ., 1906, vol. 77, p. 31.)-The conversion of methylene blue, by lactose and allied bodies, into a colourless compound may be utilized as a test for the freshness of milk. Two C.C. of milk are placed in a test-tube, 0.2 C.C. of a very dilute methylene blue solution is added, and a layer of liquid paraffin poured over the mixture. The test-tube is then placed in an incubator at a temperature of 37" C., and the discharge of the colour takes place after a varying period of time. Fresh milk usually shows the change after eight or ten hours, whilst milk that has been kept for some time reduces the methylene blue after a period varying from a few minutes to half an hour.w. P. s. Determination of Fat in Cheese. M. Weibull. (Zeit. Unterswh. Nahr. Gelzussm., 1906, xi., 736-738.) - The following method of applying the Gottlieb process to the determination of fat in cheese is described : From 2 to 3 grams of the cheese are placed in a graduated tube and heated with 10 C.C. of ammonia to a temperature of 75" C., with occasional shaking. I n most cases the cheese dissolves readily, in which case the contents of the tube are cooled and 10 C.C. of alcohol are added. If the cheese does not go into solution, the heating is continued after the addition of the alcohol. To the cold solution are then added 25 C.C. of ether; the tube is closed with a cork and the mixture well shaken; 25 C.C.of petroleum spirit are now introduced, and, after again shaking, the tube and its contents are placed aside for one hour. An aliquot portion of the ethereal layer is then withdrawn, evaporated in a weighed flask, the residue of fat is dried for two hours at 100" C. and weighed. Instead of taking a portion of the ethereal solution, the whole of the fat8 may be extracted by shaking out the mixture several times with the ether-petroleum spirit mixture. w. P. s. The Determination of Sodium Chloride in Egg-Yolk. L. and J. Gadas. Ann. de Chim. anal., 1906, vol. 11, p. 249.)-The ordinary methods are stated to give too low results, and the following method is therefore recommended : 1 gram oE the sample is covered with 12 grams of pure potassium nitrate, 2 drops of Tc sodium hydroxide solution added, and the crucible gently heated, with precautions to prevent loss in the deflagration.The saline residue is dissolved in water, the solution exactly neutralized with nitric acid, and the chlorides determined by titration with & silver nitrate solution. C. A. M. Influence of the Oxidation of Ethyl Alcohol on the Maturing of Brandy and Wine. A. Trillat. (Chem. Centr., 1906, i., 580; through Pharm. JozLrn., 1906, vol. 77, p. 733.)-It is shown that ethyl, propyl, butyl, and amyl alcohols are readily oxidized to acetals, especially in the presence of ferric chloride or hydrochloric acid.300 THE ANALYST. The author suggests that the maturing of spirits and wines is due partly to the formation of these acetals, which are highly aromatic substances, and partly to the formation of esters. A mixture of dimethylaniline and dilute sulphuric acid may be employed for detecting these acetals, a blue or green coloration being produced in their presence.w. P. s. A Test for Bleached Flour. J. T. Willard. (BzcZl. Kansas State Board of HeaZthz: 1906, ii., 160.)-Flours which have been bleached by the action of oxides of nitrogen ( c j . ANALYST, 1906, 227) may be detected in the following manner: The reagent employed is prepared by heating 0.1 gram of a-naphthalamine with 20 C.C. of concentrated acetic acid, decanting the clear liquid and mixing it with 130 C.C. of dilute acetic acid. To this solution is added 0.5 gram of sulphanilic acid dissolved in 150 C.C.of dilute acetic acid. A small quantityof the flour is nov shaken with a few C.C. of water, about 2 C.C. of the reagent are added, and the mixture allowed to stand for a short time. The delicacy of the reaction may be increased by subjecting the flour-and-water mixture fo centrifugal action, and then testing the clear aqueous liquid. It is possible that after a sufficient lapse of time the nitrites in the flour may become completely oxidized, but a sample exposed in a thin layer under a large bell-jar for nearly three If nitrites be present, a distinctly pink coloration develops. months still reacted strongly. w. P. s. The Detection of Rice-Flour in Wheat-Flour. G. Gastine. (Comptes Rendus, 1906, cxlii., 1207-1210.)-Two drops of a solution of a suitable dye-stuff are mixed on a cover-glass with a small quantity of the flour, the solvent evaporated at aso C.to 30" C., and the residue dried at 50' C., then heated for some minutes at 110" C. to 130" C., and examined in Canada balsam under the microscope. After this treatment the hilum of the rice-starch granules is clearly shown, whilst in the case of wheat it is rarely very distinct. Isolated starch granules of rice are exceptional, but masses of the starch cells, with their characteristic symmetrical markings, are to be seen. The method is stated to be capable of detecting as little as 1 to 2 per cent. Qf rice-flour. Suitable dye-stuffs mentioned are aniline blue, certain cotton blues, blue C4B, Meldola blue, aniline green, methyl green, auramine, and aniline violets, the most suitable strength of the solution being 0-05 gram in 100 C.C.of 33 per cent. alcohol. The dye-stuffs are not essential, they only render the markings more distinct. Good results can also be obtained by heating the flour without dye-stuff, and then treating it with osmic acid, silver nitrate (with exposure to sunlight), or gold chloride. The method is also satisfactory with maize and buckwheat flour, the starch granules of which behave like rice. The hilum in the cells of potato or arrowroot starch is also made clearly visible in the same way. Unlike most starches, these last are dyed by contact with the solutions of the dye-stuffs. C. A. M. The Determination of Malic and certain other Fixed Acids in Fruit- Juice. W. Mestrezat. (Comptes Rendus, 1906, cxliii., 185, 186.)-This method, which is stated to be specially applicable to musts and wines, is based upon the fact that the malate, tartrate, and succinate of barium are insoluble in alcohol of 75 perTHE ANALYST.301 cent. strength, whilst the barium salts of the other acids (lactic, glycollic, etc.) that may be present remain in solution. A known volume of the juice is neutralized with barium hydroxide, and then rendered slightly acid by the addition of 3 or 4 drops of 3 per cent. acetic acid, and concentrated to 15 C.C. by boiling for a few minutes in vacuo. It is next treated with 2 C.C. of a 30 per cent. solution of barium acetate, and sufficient alcohol added to bring the alcoholic strength to about 80 per cent. The Insoluble substances are collected, washed with 80 per cent.alcohol, and then taken up with water (about 12 to 15 c.c.) containing sufficient sulphuric acid to liberate the acids from the barium salts. The magma is diluted to a definite volume, say 100 c.c., with concentrated alcohol, the gums, pectin derivatives, and proteids being pre- cipitated, whilst the acids and tannins remain in solution. The tartaric acid is precipitated by adding potassium chloride and potassium acetate to 80 C.C. of the filtrate, then diluting the liquid to 100 c.c., and allowing it to stand for forty-eight hours at 15" C. The precipitated hydrogen potassium tartrate is filtered off and washed with alcohol of 65 per cent. strength, whilst the filtrate will only contain traces (0.01 gram per 100 c.c.) of tartaric acid, for which an allowance can sub- sequently be made.The filtrate is next neutralized with a saturated solution of barium hydroxide, rendered faintly acid as before with acetic acid, and brought up to 80 per cent. alcoholic strength by the addition of strong alcohol. The precipitate is dissolved in water slightly acidified with hydrochloric acid, and yields a solution containing only malic and succinic acids, plus tannins, which can be completely separated by Laborde's aceto-mercuric reagent. The malic acid is determined by titration with potassium permanganate, in the presence of sulphuric acid, after removal of all traces of alcohol. After oxidation of the malic acid the liquid is evaporated to dryness with sand, and the succinic acid extracted with ether from the dry residue.This method is stated GO give absolutely concordant results, and in test experiments in which the three acids were added to organic liquids, the theoretical quantities were recovered. Sugar and glycerin have no influence on the determination. C. A. M. The Determination of Tartaric Acid in Wine Lees and Tartrates. P. Carles. (Bull. Xoc. Chim., 1906, xxxv., 571 -575.)-Various precautions required to obtain accurate results in the method of Goldemberg and Gbromon are embodied in the following modification, devised by the author. I t is also shown that the presence of calcium phosphate has no appreciable influence, but that iron phosphate causes a loss of about 1 per cent. of tartrate, and that the presence of aluminium may increase this loss to 2 per cent.I n the new method 6 grams of wine lees or 3 grams of crude tartrate are finely powdered and digested for an hour with 9 C.C. of dilute hydrochloric acid (specific gravity 1-10>, the flask being shaken from time to time. An equal amount of water is then added and the digestion continued for another hour, after which the contents of the flask are made up to 100 c.c., thoroughly shaken, and filtered. Fifty C.C. of the filtrate are poured into a beaker already containing 18 C.C. of a 20 per cent. solution of potassium carbonate, and the mixture gradually heated, and finally boiled for fifteen to twenty minutes, the vessel being meanwhile kept covered. The liquidis now filtered off with302 THE ANALYST. the aid of suction, the filter washed with boiling water, and the filtrate and washings evaporated on the water-bath until not less than 13 C.C.or more than 15 C.C. are left. It is next left to cool for fifteen minutes, after which 3 to 4 C.C. of glacial acetic acid (specific gravity 1.064) are added and the mixture shaken for ten minutes, and then mixed with 100 C.C. of alcohol of not less than 94 per cent. strength. The precipitate becomes granular and crystalline after being stirred for five minutes, and the super- natant alcohol can be decanted on to a filter. The residue is washed by decantation about a dozen times with fresh portions of 10 C.C. of alcohol, the washing being then completed on the filter with the aid of suction until the washings are neutral. Finally the filter and precipitate are boiled with 100 C.C. of water for a, minute, and the solution immediately titrated with standard sodium hydroxide solution with phenolphthalein as indicator.For wine lees the ordinary correction is made-viz., for a yield of 20 per cent. a deduction of 0.70, and for a yield of 20+n per cent. a deduction of 0.70 + (n x 0.2). This correction is not required in the case of tartar and crude tartrates. C. A. M. Starch in Powdered Capsicum. J. Hoekauf. (Zeits. Oesterr. Apoth. Ver., 44, 303; through Pharrn. Journ., 1906, vol. 77, p. 106.)-Powdered capsicum is frequently mixed with about 1 per cent. of fixed oil to improve its appearance, and such oiled powders often contain more or less maize starch, etc. The starch. in these samples may be detected, without previous removal of the oil, by mixing a little of the powder on a slide with an alcoholic solution of iodine, and then adding a solution of chloral hydrate.When examined under the microscope, many of the oil globules will appear dark blue, and remain so for half an hour. After the preparation has become quite clear, a little more chloral hydrate is added. I n this way the various tissues are shown clearly, and the starch now appears pale blue. w. P. s. The Differentiation of Pharmaceutical Benzoic Aeids. Cormimbmf and L. Grosman. (Ann. de Chinz. a d . , 1906, vol. 11, pp. 243, 244.)-Benzoic acid prepared from gum benzoin has a greater commercial value than benzoic acid prepared synthetically from benzyl chloride, and the former is therefore frequently substituted for the latter.A simple method of differentiating the two products is to dissolve a few grams in hot water containing sodium carbonate, when the benzoin acid emits a characteristic pleasant odour, whilst the synthetic acid gives off a quite different odour, recalling that of parsley. The latter odour can be masked, however, by perfuming the benzoic acid with, e.y, vanillin, or by subliming it with a little gum benzoin. Another test is based on the fact that the synthetic acid always retains a certain proportion of organic chlorine, which can be detected by igniting 5 grams of the sample with an equal quantity of sodium carbonate, extracting the residue with hot water, acidifying the filtrate with nitric acid, and adding silver nitrate. Benzoic acid from benzoin gives only an insignificant reaction, whilst the synthetical product shows unmistakably the presence of chlorine.C. A. M. An Adulteration of Oil of Cade. C. Pepin. (Jourrrz. Phamz. Clainz., 1906, xxiv., 49-58.)-Oil of cade is stated to be frequently adulterated with a variable pro-THE ANALYST 303 portion of pine-tar oil. The addition may be detected by shaking 1 C.C. of the sample with 15 C.C. of petroleum spirit, filtering the extract, and shaking 10 C.C. of the filtrate with 10 C.C. of a 5 per cent. solution of neutral copper acetate. The mixture is allowed to stand, and 5 C.C. of the petroleum spirit layer decanted? mixed with 10 C.C. of ether, and filtered. Should the cade oil have contained pine-tar oil, the liquid will have an intense green colour, whereas a pure product will give only a light brownish-yellow tint.This reaction is probably due to the formation of green copper resinates soluble in petroleum spirit from the resin acids in the pine-tar oil. Hirschsohn asserted that a similar reaction was given by pure oil of cade, but the authors have never found this to be the case with samples of known purity obtained by distillation from Juniperus oxycedrus alone. In their opinion every oil giving the reaction ought to be rejected, though the absence of a green coloration does not necessarily mean that the oil is genuine. The test is capable of detecting 10 per cent. of pine-tar oil, and a smaller addition would not pay. C. A. M. Characteristics of Essential Oil of Rue. H. Carette. (Journ. Pharm. Chiin., 1906, xxiv., 58-62.)-1t is commonly accepted that commercial oil of rue is the product of Ruta graveoZens, and that it contains about 90 per cent.of methylnonyl- ketone. I t was shown, however, by Soden and HenlB, and subsequently by Leesand Power, that oil of rue from Algiers contained a large proportion of methylheptyl- ketone. The author was unable to detect this compound in French oil from R. graveoZens, and has therefore examined the Algerian products. An oil known in Algiers as essence de rue d'dtL, is obtained from R. montana. This consists, in the main, of methylnonylketone, and therefore solidifies readily in the winter. I t s solidification point ( + 5" to + 8" C.) approximates closely to that of the oil from R. graveoleizs (+So to +lo" C.). Another product, termed essence de rue d'hiver, is distilled from R.bracteosa, and its properties differ greatly from those of the oils from €2. montana and R. graveolens. I t does not solidify in winter, its solidification- point being about - 18" C., and it does not become liquid again until warmed to about -10" C. I t combines almost entirely with sodium bisulphite, the combining sub- stances consisting chiefly of methylheptylketone, whilst methylnonylketone is only present in small quantity. All these diflerent essential oils of rue are soluble in 2 to 3 parts of 70 per cent. alcohol, whilst the presence of oil of turpentine or petroleum spirit prevents the formation of a clear solution. The isolation of the ketones and determination of their melting-points will give valuable indications as to the origin and quality of a given oil of rue.C. A. &I. Separation of Brucine and Strychnine by Treatment with Nitric Acid. W. C. Reynolds and R. Suteliffe. (J0217*?2. SOC. Chenz. Ifid., 1906, XXV., 512-515. -An examination of the various modifications of this process proves that the conditions proposed by both Stoeder and Gordin give slightly more accurate results than Keller's original process. The conclusions arrived at are-(1) that for an amount of total alkaloid up to 0 4 gram the reacting solution should contain at least '7 per cent. of HNO,; (2) that the oxidation of the brucine is complete after ten minutes, when the reaction should be stopped ; (3) that the temperature should notTHE ANALYST. exceed 25" C. ; (4) that excess of caustic soda or potash should be used to liberate the strychnine, not sodium carbonate or ammonia; and (5) that nitric acid of specific gravity not less than 1.42 should be used ; otherwise the addition of a trace of nitrite may be necessary to start the reaction (cd.ANALYST, xxx., 261). W. H. S. Determination of Cantharidin in Cantharides. K. Siegfried. (Schtoeiz. Wochenschr., xliv., 342 ; through Pharm. Jown., 1906, vol. 77, p. 9.)-The following method is proposed and is a modification of that devised by Panchaud for the Swiss Pharmacopceia : Fifteen grams of the finely-powdered cantharides are placed in i;lt 250 C.C. Erlenmeyer flask, to which are added 150 grams of chloroform and 1 C.C. of hydrochloric acid of a specific gravity of 1.124. The mixture is shaken for several minutes, and then allowed to stand for twenty-four hours, with occasional shaking. After filtration through a covered filter, 100 grams of the filtrate are evaporated at as low a temperature as possible on the water-bath, and the residue treated with 10 C.C. of petroleum spirit. The crystals are collected on a weighed filter, washed with EL little petroleum spirit, and dried at a temperature of 50" C. w. P. s. Examination of a Sample of Eucalyptus Oil, an Overdose of which caused Death. F. A. U. Smith. (Pharm. JOZLT~., 1906, vol. 77, p. 662.)-Whilst the relative therapeutic values of the two classes of eucalyptus oil, known respectively as the cineol oils and the phellandrene oils, is not at present precisely known, the Pharmacopceia gives preference to the former class of oil, the oil of Eucalgpt;7cs globzdus; but the latter class, as typified by the oil of E. amygdnlinn, was oficial until the year 1898. A case of poisoning by an overdose of the oil having occurred at Derby, the author examined the oil with a view of ascertaining whether it was composed chiefly of cineol or phellandrene. The results obtained were : Specific gravity, 0.919 at 15" C. ; rotation in 100 mm. tube, + 4.47O ; cineol, 52.65 per cent.; phellandrene, absent. The deceased took about half a wineglassful with a similar quantity of warm water. w. P. s.

ISSN:0003-2654    

DOI:10.1039/AN9063100299

出版商:RSC    

年代:1906

数据来源: RSC

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304 THE ANALYST. ORGANIC ANALYSIS. Influence of Dilution and the Presenee of other Reducing Sugars on the Osazone Test for Glucose and Fructose. H. C. Sherman and R. H. Williams. (Journ. Amer. Chern. ,Toe., 1906, xxviii., 629-632.)-1n pure glucose solutions, tested at constant volume with fixed amounts of phenylhydrazine hydro- chloride and sodium acetate, the time required for the precipitation of the osazone varies with the amount of glucose present, and is nearly constant for any given dilution. I n solutions containing only about 0-1 per cent. the time required for precipitation is much reduced by the presence of 1 per cent. or more of sucrose, but only slightly by the presence of 5 per cent. of raffinose. Solutions of fructose and invert sugar show similar variations with concentration, those of fructose always yielding a pre- cipitate of osazone in about one-third the time required for the same amount of glucose, and those of invert sugar in slightly more than one-third the time.Sucrose also slightly accelerates the osaeone precipitation in dilute solutions of fructose.THE ANALYST. 305 Maltose retards the precipitation of glucosazone, interfering much more seriously in the case of glucose than with fructose, and lactose interferes similarly, but to a greater degree. W. H. S. Esterification as a Cause of Error in the Determination of Sugar. Talon. (Ann. de Chim. anal., 1906, vol. 11, pp. 244, 245.)-If alcohol is present in a mixture in which cane-sugar is to be determined by inversion, it is necessary to remove the alcohol to prevent the formation of esters.In the case of dextrose, ethyl- dextrose, a non-reducing body, is formed. The esterification increases with the time and temperature, and in the presence of concentrated alcohol the yield may amount to nearly 100 per cent. The esterification of dextrose and levulose ceases when the proportion of alcohol is less than 40 per cent., but an error is still produced in polarimetric determinations. In the absence of an acid no esterification takes place. Methyl-alcohol acts in a similar manner, and glycerin also forms esters with dextrose and levulose; but the small amount of glycerin in fermented alcoholic liquids has no influence on the determination of sugar. C. A. M. Optical Rotation and Density of Alcoholic Solutions of Gliadin.W. E. Mathewson. (Journ. Anzer. Chem. SOC., 1906, xxviii., 624-628.)-The specific rotation of gliadin in 70 to 75 per cent. alcohol is practically independent of the gliadin con- centration, but in 70 to 80 per cent. alcohol decreases with increase in the alcoholic concentration. It increases slightly with increase of temperature between the limits 20' C. to 45" C. The variation in density of gliadin solutions for such concentrations as would be met with in flour analysis is so small as to render even an approximate determination of gliadin in alcoholic solution by means of the density extremely difficult. W. H. S. On the Determination of Petroleum, Petroleum Distillates, and Benzene in Oil of Turpentine and its Substitutes, Richard Bohme. (Chem. Ztg., 1906, xxx., 631.)-In a long paper the author compares and criticises a number of methods for the detection of adulterants in oil of turpentine, and also communicates a table containing the results obtained by him in the examination of a number of samples. He has modified Herzfeld's sulphuric acid method in order to save time, and works as follows : Twenty C.C.of a mixture of 1 volume of fuming and 3 volumes of concen- trated (1.84) sulphuric acid are placed in a specially constructed flask which holds about 40 C.C. up to its neck, the latter holding an additional 10 C.C. and being graduated in 6 C.C. To the acid 10 C.C. of the oil to be examined are slowly added ; after cooling, the whole is well mixed and allowed to stand ir, the stoppered flask for one hour; concentrated sulphuric acid is then cautiously added until all the unattacked oil has been brought into the neck of the flask, which is then allowed to stand for another two to three hours, after which time the volume of the residual oil is read off.Occasionally the flask must be allowed to stand for six hours before the volume is read. The author finds that pure oil of turpentine treated in this way will give a residue of about 0.9 c.c., but sometimes even 1.6 e.c. are found; the refractive index of this, however, is higher than that of the original oil. In mixtures306 THE ANALYST. of oil of turpentine with petroleum products, a residue of 1.25 C.C. corresponds to an addition of about 5 per cent. of petroleum, 1.70 to 10, 2-00 to 15, 2.50 to 20, 2.80 to 25, 3-35 to 30, 3.75 to 35, 4.15 to 40, and 4-50 C.C.to 45 per cent. If a, residue of 4.5 to 5.5 C.C. is obtained, the test should be repeated, using 20 C.C. of ordinary concentrated acid; if more than 5-5 C.C. is found, the test is again carried out with only 10 C.C. of ordinary acid. The percentage of petroleum is obtained by multiplying the volume of residue found by 10. If benzene is the adulterant present, it must be remembered that a considerable proportion of a commercial benzene is attacked by sulphuric acid, especially if the temperature be allowed to rise; hence the results obtained are not so reliable. Commenting on the above paper, Herzfeld (Chem. Ztg., 1906, xxx., 697) mentions that he now carries out his method in a separating funnel graduated in ?n C.C.instead of in a burette. For the detection of small quantities of benzene, the oil should be fractionated, and the different fractions obtained examined. I n doubtful cases the residual oil left after treatment with sulphuric acid is tested by Burton's nitric acid method, as well as by the refractometer. A. G. L. The Reduction of Cinnamic Acid to Cinnamene by Mould Fungi. Oliviero. (Jourm. Pharm. Chirn., 1906, xxiv., 62-64.)-The enzymes secreted by Aspergdlus niger, PenicilZium glaz~cuw~, and possibly by other mould fungi, are capable of effecting a rapid reduction of cinnamic acid to cinnamene. Thus a cultivation of A. niger, grown on Raulin's fluid until complete development of the mycelium, and then thoroughly shaken and filtered through a Chamberland filter, yielded a clear liquid, which, when shaken with a weak solution of sodium cinnamate, immediately gave the characteristic odour of cinnamene.The reaction is sufficiently sensitive for cinnamic acid to be used zts a reagent for the detection of these mould fungi in medicinal preparations and food products. I t affords the explanation of the occa- sionally rapid deterioration of pharmaceutical products, such as balsam of Tolu, which are rich in compounds of cinnamic acid. Muskone, the Aromatic Constituent of Musk. H. Walbaum. (Jik. Prak. Chern.; through Chem. Zeit., xxx., 194, and Pharm. Journ., 1906, vol. 77, p. 31.)-The odoriferous constituent of musk, muskone, is present in musk in only very small proportion. It is a viscid, colourless oil, very slightly soluble in water, but readily soluble in alcohol.It has a powerful and agreeable odour of musk, and, like ionone, rapidly exhausts the nerves. By steam distilling 500 grams of musk for several days, the authbr obtained 1.4 per cent. of a brown oil, and on redistilling this under a pressure of 9 mm., about one-half came over between 200" C. and 210" C. as a yellowish-brown viscid oil. After warming the latter with an alcoholic solution of potassium hydroxide, it distilled under 7 mm. pressure at 160" C. to 164" C.; the distillate gave with semicarbazide a crystalline carbazone, from which the oil was C. A. M. regenerated by sulphuric acid. Muskone is, therefore, a ketone. w. P. s. Determination of Total Soluble Bitumen in Paving Materials. S. Avery and R. Corr. (Joum.Anzer. Chem. SOC., 1906, xxviii., 648-654.)-The method proposed by the authors consists in extracting with carbon bisulphide in a Soxhlet extractor a,THE ANALYST. 307 weighed quantity of the material contained in a capsule of hardened filter-paper. The extraction is continued until the solvent has siphoned over colourless some ten times, the solvent with the extracted bitumen ignited in a platinum dish, and the percentage of residue determined. The filter-paper and its contents are dried at 110" C., cooled in a weighing-bottle, and weighed, the loss in weight less the material recovered from the solvent representing the amount of dissolved bitumen. The results thus obtained for Bermudez and Malthas asphalts agree closely with those given by the methods of Dow and Richardson, in which the solution is filtered through asbestos or by Richardson's centrifugal method.The practice sometimes adopted of igniting the filter-paper apart from its contents, after extracting the bitumen, and adding the ash to the residue before weighing, is shown to give distinctly too high results. W. H. S. A Method of Testing the Hardness and Elasticity of Varnishes. A. P. Laurie and F. G. Baily. (Jozmz. Roy. Scot. SOC. Arts, 1906, xvii., lOl-lll.)-The authors have devised a simple ap- paratus to determine the degree of pressure required to make a scratch upon a film of the given varnish on a glass plate, thus obtaining a numerical value for the hardness and toughness. The apparatus consists of a central rod moving easily in a vertical direction through openings in two supporting brackets.On the upper part of the rod is a screw thread on which is a running nut, prevented from turning by guides which project into the wings of the nut, whilst by turning a milled head at the top the rod is made to revolve and the nut to travel up or down. A helical spring is fixed at one end to the lower part of the nut and at the other to the lower bracket, whilst the lower end of the rod carries a blunt steel point. Thus by turning the milled head at the top the point can be raised or pressed down on to the plate. A scale is attached to one of the guides of the running nut, and the position at which the point is just at the height of the film is taken as zero. Fig. 1 on the scale represents 0.1 Q Q I- kilo, No. 2, 0.2 kilo, and so on.The point is rounded to a spherical surface and has a radius of 1 mm. The method of using the instrument is to draw308 THE ANALYST. the varnished plate slowly under the point, the pressure being meanwhile steadily increased until a white scratch becomes visible. No notice is taken of grooving, which may even be regarded as a sign of toughness in a varnish. The spring used by the authors gave a maximum pressure of 1,200 grams, but few of the best varnishes required this pressure. Duplicate determinations by different observers differed from one another by not more than 5 per cent. The films of varnish were prepared by cleaning the glass plate, polishing it with leather, and placing it in the water-oven with the sample of varnish. The varnish was then poured on the centre of the plate and distributed with the finger, after which the plate was warmed on the top of the oven so that the film became level and uniform, and was finally placed in a cupboard with levelled shelves.Experiments were made with varnishes prepared from common rosin and oil and from gum animi, and kauri and white Manilla copals, and with representative commercial varnishes. The following table gives typical results obtained in determinations of the rate of drying : Varnish. Rosin and oil . . . ... Picture copal ... ... Ra;i chdich oak.** ... ... Y ¶ 9 9 ... ... Carriage ... ... ... Finest oak ... ... Maple ... ... ... Amber . . . ... ... Floor . . . ... ... 9 , ... ... ... Carriage ... ... . . I One and a Half Months. Two and a Half' Months.4.5 6.5 10.0 Four Months. 1 *2 6.5 3.5 4.8 1-5 5.5 5.5 6.5 1.0 Eight Months. Twelve Months. 1.9 9.5 6.0 12.5 9-0 12.0 10.0 1.0 - Experiments were also made to determine the effect of exposure to air and frost upon diEerent vanishes. It was found that an inferior copal varnish and the amber varnish showed signs of deterioration after a fortnight, and had disappeared in three months. The hard church oak varnishes had cracked in three months, whilst the other trade varnishes, though apparently sound and transparent, had decreased in hardness to one or two, and gave a crumbling scratch. Hence the test is capable of detecting decay of a varnish before the appearance of outward signs, C. A. M. Electrical Method for the Simultaneous Determination of Hydrogen, Carbon, and Sulphur in Organic Compounds.H. N. Morse and C. W. Gray. (Amer. Chern. Joumz., 1906, vol. 35, pp. 451-458.)--An extension of Morse and Taylor's method (ANALYST, xxx., 321) to include the determination of sulphur, the apparatus employed being, with slight modification, similar to that previously described, The coils in the vicinity of G are wound tightly about the porcelain tube to make room for a long platinum boat (F), in which is placed a weighed quantity of pure PbO, forTHE ANALYST. 309 the absorption of the SO, produced, the rear of the boat being open to facilitate contact between the products of combustion and the oxide. Asbestos plugs (J J) replace the rolls of oxidized copper wire gauze which formerly preceded and followed L./ F I G .1. the boat K. For the complete absorption of nitrogen oxides, a glass tube (A), filled with asbestos covered with PbO,, is inserted between the combustion-tube and the usual absorption apparatus for water and carbon dioxide, and maintained at 175" C. by surrounding it with an electrically-heated graphited porcelain tube (B) about 300 mm. long, and provided with an asbestos covering (C). Fig. 2 shows the FIG. 2. complete apparatus set up for use. I n making an analysis the boat containing the weighed quantity of peroxide is inserted at F, and that containing the substance to be analysed at K, the two circuits, one through the combustion apparatus, the other through ABC, closed, and dry air passed through the apparatus. After drying out completely, the absorption train is joined to A, the current of dry air continued, oxygen admitted at D, and the substance in K and the plug of asbestos in front of the boat heated by a lamp.The contents of the boat F after a combustion consist of a mixture of PbQ,, PbSO,, and, if the substance con- tained nitrogen, a small quantity of Pb(NQ,),. The quantity of PbO yielded by unit weight of the peroxide is estimated before commencing the combustion, so that the amount of PbO in the boat after the combustion is known, and the excess over this, after reducing the peroxide and nitrate to oxide by heating in a current of air or nitrogen, gives the amount of sulphur as SO,. The method has given satisfactory results with sulphonal and other organic compounds. W. H. S.310 THE ANALYST.Determination of Total Sulphur in Coal Gas. E. P. Harding. (Joum Amer. Chem. Xoc., 1906, xxviii. , 537-541.)-A modification of Drehschmidt's method is proposed, in which the gas is burnt in the presence of bromine vapour, the sulphur dioxide being thereby immediately oxidized, in the presence of water of combustion, to sulphuric acid, which is then aspirated through a solution of K,CO,, and the sulphur precipitated and weighed as BaSO,. The apparatus employed is shown in the figure, in which G is a purifying tower, 45 cm. high and 6.3 cm. in diameter, filled with pumice - stone saturated with a 338 per cent. solution of KOH and contained between glass- wool layers (WW) ; H is a dropping funnel for deliver- ing continuously the potash solution ; and K a retort, 24 cm.deep, 16 cm. in cross- section, with a delivery tube 46 cm. long, fitted into the flask L by the rubber stopper 0. L, M, and N are heavy glass suction bottles, with the respective diameters 10 , 8.9, and 6-3 cm., connected at P and R with rubber tubing, and attached through the glass tap S with the suction pump. C, C', and C" are adjustable wooden supports. The burner I is connected at y with the meter, and at V, by means of a short piece of rubber tubing, with the purifying tower. I t is of hard glass, and is fitted into the tubule of the retort with the rubber stopper a. The air-supply tube E is 9 mm. in diameter at E and 12 mm. at Z, and D, the gas-supply tube, is 5.8 mm. in diameter. The latter has opposite holes B for admission of air, and is drawn out at A to an opening sufficiently small to deliver, under aspiration, 0.35 to 0.5 cubic foot of gas per hour.The burner is first connected with the meter and tower, the gas turned on, ignited, and allowed to burn for fifteen minutes, the retort and absorption flasks being meanwhile cleaned and partly filled with a 5 per cent. solution of K2C0,, 30 C.C. each being put into N and M, 50 C.C. into L, and 30 C.C. together with 4 C.C. of bromine into the retort K. The flasks and retort are then connected up, the gas turned off,THE ANALYST. 311 the burner. inserted into the tubule of the retort, and air aspirated through the apparatus for ten minutes. Aspiration is then momentarily discontinued, the burner removed from the retort, the gas turned on and ignited, the burner reinserted and the aspiration continued and regulated with the cock S.After 18 to 2 cubic feet of gas have been burned, at the rate of 0.35 to 0.5 cubic feet per hour, the gas is turned off, the aspiration being continued until the apparatus has cooled down to room tempera- ture. The burner is then withdrawn from the retort and rinsed wit4 water into a 500 C.C. beaker, the retort and absorption flasks disconnected, their contents poured into the beaker, and these rinsed several times with small quantities of water. The contents of the beaker are acidified with HCI, concentrated to 100 c.c., transferred to a No. 3 beaker, and the sulphur precipitated and weighed as BaSO,. C. D. Jenkins (ibid., 1906, xxviii., 542-544) describes a new and easily portable form of apparatus for the purpose, consisting of a system of condensers, at the bottom of which 0.8 to 1 cubic foot of gas, measured through a small dry meter, is burned in an ammoniacal atmosphere at the rate of 0.6 cubic foot per hour. The sulphur com- pounds form sulphur dioxide and sulphur trioxide, which, conibined with the ammonia, are dissolved in the condensed water and collected, the apparatus being washed out with 200 C.C. of distilled water. To this solution are added 2 to 3 C.C. of bromine water, the liquid concentrated to 30 to 40 c.c., and an excess of a hydrochloric acid solution of barium chromate added. The whole is then gently boiled, an excess of dilute ammonia added, again boiled for a minute, filtered, and washed. The ammonium chromate in the filtrate, after being boiled in a stout flask with a Bunsen valve to expel air, is cooled and titrated direct with stannous chloride, using the iodo-starch blue to accentuate the end-point. The chromic acid found is equivalent to the sulphuric acid in the original solution. W. H. S.

ISSN:0003-2654    

DOI:10.1039/AN9063100304

出版商:RSC    

年代:1906

数据来源: RSC

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THE ANALYST. 311 INORGANIC ANALYSIS. Rapid Method of Babbitt Metal Analysis. H. Yockey. (Joumz. Bmer; Chem. SOC., 1906, xxviii., 646-648.)-0ne gram of filings or borings is treated in a small beaker with 20 C.C. of nitric acid (specific gravity 1-42) and water (1 : a), placed on the water-bath and covered with a watch-glass until all action has ceased. It is then evaporated to dryness and baked in an air-bath at 120' C. for one hour. The residue is moistened with concentrated HNO,, 30 to 40 C.C. of hot water added, the whole boiled vigorously for five minutes, and the mixed oxides of tin and antimony filtered off, washed, dried, ignited in a porcelain crucible, and weighed as SnO, + Sb,O,, any metal reduced in burning the filter being oxidized with a few drops of concen- trated HNO,.The filtrate is diluted to 250 C.C. in a calibrated flask, and 50 C.C. pipetted out for estimation of lead, to which is added 10 C.C. of ammonia (1 part ammonia, specific gravity 0.9, to 1 part water) and 6 C.C. glacial acetic acid, the mixture heated to incipient boiling, and the lead titrated with a solution of ammonium molybdate, I C.C. of which = 0.01 gram lead, and standardized against pure lead dissolved ill HNO,, a 1 in 300 solution of tannic acid being used as indicator. To the remaining 200 C.C. of the solution is added sodium carbonate till a precipitate forms, then 1 or312 THE ANALYST. .2c.c. of ammonia. After well stirring and allowing to settle, any copper present is titrated with standard KCN solution (1 C.C. of which = 0-0025 gram copper) until the blue colour disappears.The antimony is estimated alone on a further quantity of metal, for which 1 gram of filings is treated in a 150-C.C. beaker with 1 gram of potassium iodide, 40 C.C. of HCl, and 40 C.C. water, boiled gently for one hour, filtered, and the precipi- tate washed with hot dilute HC1 (1 : lo), then with hot water, and finally with alcohol. A duplicate filter-paper is treated in the same way, both dried at 100" C. for one hour, and the precipitate weighed as metallic antimony. This, calculated to Sb,O,, and subtracted from the mixed tin and antimony oxides, gives the weight of SnO,, and hence the percentage of tin. W. H. S. Gutzeit Test for Arsenic. J. A. Goode and F. M. Perkin. (Journ. Xoc. Chem. Ind., 1906, xxv., 507-512.)-The authors prefer to use magnesium and ammonium chloride for the reduction in place of zinc and sulphuric acid, as when once started the evolution of hydrogen goes on gently for about two hours without further attention.The apparatus adopted consists of a conical flask, of 250 C.C. capacity, fitted with a dropping funnel, and attached through A to a U-tube containing a 10 per cent. solution of acid cuprous chloride, the exit from the U-tube being restricted by inserting a rubber cork through which passes a glass tube of 5 mm. internal diameter. About 5 grams NH,Cl are first placed in the flask, then 1 to 2 grams of magnesium turnings, wire or ribbon, added, and 10 C.C. of water run on to the mixture, the apparatus being gently shaken and placed in a basin of cold water.A piece of filter-paper soaked in mercuric chloride solution-or, better, in a strong alcoholic solution of mercuric bromide, which gives st more intense stain-is placed over the outlet and kept there for one hour, or if arsenates are present, for one and a quarter hours, the paper being then placed on a watch-glass, moistened with a few drops of concentrated hydrochloric acid, warmed, the acid poured off, the paper washed with a little water and allowed to dry. Zinc and acid is slightly more sensitive than magnesium with ammonium salts, but with the latter T&B mgm. of arsenious oxide is easily detectable. The sensibility of the magnesium is diminished by the addition of cadmium salts. W. H. S. Analysis of Molybdenum Ores. A. Gilbert. (Zeit. ofentZ.Chem., 1906, xii., 263-265.)-The following method is applicable to native molybdenum sulphide, and consists in roasting the ore, dissolving the residue in ammonia, filtering, evaporating the filtrate, and igniting the residue obtained. One gram of the finely- powdered ore is placed in a porcelain boat, which is then inserted in a combustion- tube and strongly ignited for three hours. When cold, the contents of the boat areTHE ANALYST. 313 heated for several hours with fairly strong ammonia solution, a little molybdic acid, which sublimes on to the inner surface of the combustion-tube, being also dissolved in ammonia and added to the main bulk. The solution is filtered, the filtrate is evaporated in a platinum basin, and the residue cautiously heated until a constant weight is obtained, care being taken that the bottom of the basin is only heated to a dull redness.The contents of the basin after weighing are dissolved in ammonia,, and any insoluble matter subtracted from the total weight. The matter remaining insoluble in the first treatment with ammonia may contain a trace of molybdenum, and this is determined separately by fusing the residue with sodium hydroxide, reducing with zinc and hydrochloric acid, and titrating with standard permanganate solution. w. P. s. Determination of Potassium by Neans of Platinum Tetrachloride in the Presence of Sulphates of the Alkalies and Alkali Earths. K. Regel. (Chem. Zeit., 1906, xxx., 684, 685.)-In the method proposed, the precipitation of the potassium platinum chloride is carried out in the usual way, but without previous separation of lime, sulphuric acid, etc.The precipitate is collected on a, filter, washed with alcohol, and then dissolved off the filter with hot water; an excess of magnesium powder is added to the solution, the mixture is warmed, and the pre- cipitated metallic platinum collected on a filter, washed with dilute hydrochloric acid to remove the excess of magnesium, dried, ignited, and weighed. The con- tamination of the potassium platinum chloride with sodium, calcium, or magnesium sulphate has, therefore, no influence on the determination. As the metallic platinum tends to run through the filter when washed with hydrochloric acid, especially if magnesium and calcium sulphates be present, it is better to wash it, in such case, with dilute nitric acid. w. P. s. On the Analysis of Sodium Peroxide. Richard Laseker. (Oester. Chem. zty., 1906, ix., 164.)-The author has compared the various methods for determining the available oxygen in sodium peroxide, and concludes that Grossmann’s modifica- tion (Chem. Ztg., 1905, xxix., 138) of Archbutt’s method (ANALYST, 1895, xx., 3) is the best. It consists essentially in gradually adding a mixture of 15 C.C. of dilute sulphuric acid (1 : loj and 2 drops of saturated cobalt nitrate solution to from 0.5 t;o 0.8 gram of the sample, and measuring the evolved gas over water in some form of jacketed nitrometer. For a complete analysis, the total alkalinity and the iron and alumina may be determined by the usual methods. The specific gravity may be determined by means of benzene dehydrated by standing ovnvr sodium peroxide. Great care should be exercised in the sampling. A; G. L.

ISSN:0003-2654    

DOI:10.1039/AN9063100311

出版商:RSC    

年代:1906

数据来源: RSC

摘要:

314 THE ANALYST. APPARATUS. Improved Extraction Cup. E. B. Warren. (Chem. Nezus, 1906, 93, p. 228.) -The essential feature of this cup is that the substance extracted is acted upon by the pure solvent, at the boiling-point of the latter, thus greatly facilitating the extractionof difficultly soluble sub- stances, such as Carnauba wax by acetone. Two forms are described, that shown in Fig. 1 having a discharge pipe from the bottom, which is carried upwards to a point below the top of the cup, allowing the residue to be dried in a stream of any gas, if liable to undergo change during drying in the ordinary way, while in Fig. 2 the cup containing the substance to be extracted is supported in a tube, and the solvent in the cup kept at a height corresponding to the height of the outer tube.The bottom of either cup is covered by a plug of wool, the material under examination weighed into it, and the cup placed in a flask, into which is poured the solvent. The flask is then attached to a reflux condenser so arranged that the condensed solvent falls back into the CUP, percolates through the material, and passes away through the outlet back into the flask. W. H. S. New Form of Absorption Tube. E. P. Perman. (Chenz. Xews, 1906, xciii., 213.)-This tube is devised to prevent any possible suck- ing back of the absorbing liquid into the generating flask during the estimation of ammonia, chlorine (from peroxides), etc. The long bulb C is 3.5 inches long and 1 inch in diameter; the bulbs B and D 1.25 inches in diameter, The liquid in C should just close the narrow tube a t E.A is connected with the generating flask by rubber, cork, or ground-glass joint, and a guard tube, containing glass beads moistened with the absorbent, may be connected to F. W. H. S. %+I+@** REVIEW. URIC ACID (the Chemistry, Physiology, and Pathology of Uric Acid and the Physiologically Important Purin Bodies, with a Discussion on the Metabolism of Gout). FRANCIS H. MCCRUDDEN. (New York : Paul B. Hoeber. Price: paper, $2.50 ; canvas, $3.00 net.) The work is a painstaking exposition of all that is at present accurately known as to the conditions of the formation and excretion of uric acid in the animal system. The references given to the literature of the subject are exceedingly copious, and mould appear to be exhaustive. The portion devoted to the purines is most instructive, and the whole work should be decidedly valuable to the physiological chemist.W. J. S,THE ANALYST. 315 ANALYSIS AND CONTROL OF MILK-SUPPLIES. (From the ((Chemist and Druggist” of June 16, 1906.) IN Section 8c of the International Congress of Applied Chemistry held in Rome a very interesting paper was read by A. Lane, of Rotterdam, on this subject. Ritherto the public has been protected from adulteration of milk to a great extent by the systematic taking of samples and assay of fat ” and (‘ other solids,” and the supply has in consequence vastly improved in those respects; but there still remains the fact that enormous volumes of milk are supplied for human consumption which conie from diseased cows. Tuberculosis is so prevalent that it will probably be demon- strated before long that the mixed supplies of milk from all the counties of England are tainted.Bacteriology fails to detect this except by animal inoculation, which, owing to the time involved and for other reasons, is impracticable. Very welcome, therefore, is any method leading to a, ready means of detecting diseased milk. By the ordinary routine of milk analysis it is often possible for grossly diseased milk to pass the standard, and yet it is vastly more important to the consumer that his milk should come from a healthy source than that he should be defrauded of 5 or 10 per cent. of the fat. The chief factor upon which the author depends is what he calls the (( oatalase number,” which is obtained by the introduction of 10 C.C.of the milk and 5 C.C. of hydrogen-peroxide solution into a fermentation-tube, and measuring the gas liberated by the catalase in the milk, which is increased in stale and diseased milk. I n his published analyses a most striking contrast is shown between the milk derived from different udders of the same cow suffering from parenchymatous mastitis. The disease was confined to one part of the udder, and the catalase number for that quarter was 6.6, while the healthy part yielded a catalase number 1.2 (healthy fresh milk being unity). The figures in many other diseased conditions are reported, both local in the udder and general. The author has also investigated the effect of milk from diseased cows upon the polarimetric reading, the degree of acidity, and the freezing-point, and his contention is that all these factors should be ascertained in judging a milk. His investigations lead him to the opinion that a lower reading than 4’ of the polarimeter, accompanied by a normal or slightly lowered freezing-point, indicates a milk from a diseased cow, and a catalase number above 3 indicates a decomposition advanced to such a degree that the milk should be considered unfit for human consumption. @ @ @ 4 @

ISSN:0003-2654    

DOI:10.1039/AN9063100314

出版商:RSC    

年代:1906

数据来源: RSC

摘要:

THE ANALYST. 315 NARROW ESCAPE OF A LABORATORY STAFF. A DELIBERATE attempt was made some months since to poison the entire staff of one of the most important of Public Departments, the Government Laboratory at Demerara, and it is clear that but for a succession of fortunate circumstances the design would have succeeded. For some time past a person had been lurking about the laboratory, and on two occasions at least the premises had been illegally entered. On Friday, June 1, a quantity of spirits submitted for analysis was stolen, and although the police at Broad Street Station, a few yards distant from the institution, were instructed to keep a special watch, the thief W&B not again seen near the laboratory. Just after that date Professor Harrison, the head of the department, was incapacitated316 THE ANALYST, for two or three days by a mysterious illness, and there is little doubt that he was then suffering from arsenic poisoning.I t would appear that the miscreant again entered the laboratory on the following Wednesday night. A false key was evidently used, nothing being broken or forced at doors or windows. Samples were tampered with, and this fact was immediately reported to the Government on Thursday by Professor Harrison. In the afternoon the Professor, after drinking several glasses of water, was almost overcome with a severe headache. Feeling giddy and unfit for work, he left the office earlier than usual. Though far from well the director was able to attend his office on Friday, but after again partaking of the water he had a renewal of his severe illness, and was compelled to return home.On Saturday Professor Harrison was unable to leave his bed, and on the following day his condition was so alarming that medical aid was summoned. The assistants a t the laboratory were seized with similar distressing symptoms, though, fortunately, their illness did not take the same serious turn Mr. P. V. Garraway, the second assistant analyst, Mr. Christiani, the director’s clerical assistant, Mr. Matthews, the fourth clerical assistant, and the messenger, Tambi, were all affected in more or less degree. The director was quite unable to leave his house on Monday, and the work of the department was carried on by those of his juniors, who made their appearance at the laboratory every morning-all victims of the same disorder, but never sus- pecting its origin.While the assistants were discussing the strange circumstances that every member of the staff were affected, it occurred to Mr. Garraway that the trouble might be due to lead-poisoning. The drinking water taken from the filter was subjected to a rough analytical test. Cursory though the examination was, it led to the discovery that arsenic had been placed in the water, Mr. Garraway lost no time in inspecting the filter. At the top was found this substance, in quantity suffi- cient to poison hundreds of people. The director was communicated with, and realizing the grave import of the news, he ordered that a careful analysis be made of the water. This was done without delay by Mr. E. W.F. English and IIr. Garraway. The water was seen to be heavily charged with arsenic, which, placed in the filter presumably between Wednesday night and Thursday morning, had been slowly but gradually poisoning the drinking supply at the laboratory. Happily arsenic is an extremely insoluble substance. To this fact and to the providential discovery of the poisoned source is due the escape of Professor Harrison and his assistants, who for several days ran exceedingly narrow risks of a terrible death. On further investigation it transpired that the poisoner, with double designs on the Professors, had actually entered that gentleman’s office and dropped arsenic into the ice-pitcher kept for the director’s own use. Hence the reason why the Professor was taken ill so suddenly, and at an earlier stage than Mr. Garraway and the others. For the first time since its institution, the laboratory had to be closed without notice, ’the entire staff having been rendered unfit for duty. Professor Harrison, the shock to whose system has been severe, is invalided home to England. He was very ill that night.

ISSN:0003-2654    

DOI:10.1039/AN9063100315

出版商:RSC    

年代:1906

数据来源: RSC