May, 1916
T H E JOC'RIVAL O F I N D U S T R I A L A N D E N G I N E E R I N G C H E M I S T R Y
427
for action of acid on organic matter being applied. Nor is i t usually found possible t o recover by t h e Dried a n d ground kelp decomposes in t h e soil under double titration method all the carbon dioxide from laboratory conditions, increasing t h e humus content samples of pure carbonates. t o a n extent comparable with alfalfa, manure a n d As t h e result of work done in this laboratory, a n d straw. Of t h e pentosans present, 7 5 t o 80 per cent having for its object t h e improvement of t h e Marr was decomposed in all t h e materials. method a n d a t t h e same time t h e retention of its Acknowledgment is made t o Professor D. R. essential feature, which is decomposition of soil carHoagland, a t whose suggestion t h e above work was bonates b y dilute acid a t reduced pressure and temperformed. perature, involving t h e least possible a t t a c k upon AGRICCLTURAL EXPERIMEKT STATION soil organic matter which is compatible with complete U N I V E R S I T Y OF C A L I F O R N I A , BERKELEY decomposition of carbonates a n d complete evolution of t h e gaseous carbon dioxide i n t h e minimum ESTIMATION OF CARBON DIOXIDE AS BARIUM CARperiod of time, it has been found possible t o do away BONATE APPLIED TO THE MARR METHOD with t h e objectionable double titration. This is acFOR DETERMINATION OF CARBONcomplished b y .effecting t h e absorption of t h e carATES IN SOIL bon dioxide evolved Erom t h e sample in barium hyB y C. J. SCHOLLENBERGER droxide solution contained in a Meyer bulb tube. Received December 27, 1915 Closely following t h e publication by l l a r r l of a T h e precipitated barium carbonate is filtered off method for soil carbonates, a modification embodying a n d determined as described b y Cain.' The method its essential features, which are evolution of carbon is essentially t h e same as t h a t recommended for dioxide b y boiling with dilute acid under reduced adoption as a tentative method b y t h e Referee on pressure a n d absorption of t h e evolved carbon dioxide Soils of t h e dssociation of Official Agricultural Chemin a solution of sodium hydroxide, t h e carbonate therein ists in 1 9 1 5 . E . Truog2 has described a method for t h e deterbeing subsequently estimated b y t h e well-known double titration method of Brown a n d Escombe,* mination of carbon dioxide b y absorption in a measwas extensively studied in this laboratory a n d a form ured excess of barium hydroxide solution and t i t r a of apparatus adapted t o it subsequently described tion of t h e excess of barium hydroxide, using phenolby E. W. Gaither.3 phthalein as indicator. ,4 trial was made of this Extended experience with this method, both in method also, b u t effecting t h e ab.sorption in a hleyer el-ery-day use on routine samples a n d with t h e special bulb t u b e , which seemed t o be better adapted t o t h e samples furnished by t h e Referee on Soils for t h e Asso- purpose in this instance t h a n did t h e ingenious bead ciation of Official Agricultural Chemists' work in 1 9 1 4 tower described b y Truog. The results were satisa n d 1 9 1 5 , has served t o establish t h e fact t h a t t h e factory when t h e acid used for t h e titration was decomposition of soil a t a moderate temperature standardized b y t h e use of a sample of known cari~zvacuo b y dilute hydrochloric acid is undoubtedly bonate content, as pointed out b y brad^.^ If t h e t h e most accurate of all procedures so far proposed theoretical strength of t h e acid had been employed for this determination, as it reduces t o a minimum in making t h e calculations, a considerable minus t h e activity of acid o n organic material. When t h e error might have been introduced. T h e method offers soil is treated with acid in t h e cold there will be for important advantages over t h e double titration prosome samples, depending on t h e nature of t h e carbon- cedure, a n d will probably give better results in t h e ates present, a n incomplete decomposition of carbonate. hands of operators not thoroughly familiar with t h e If t h e soil be boiled a t atmospheric pressure with acid latter method, b u t it must not be forgotten t h a t it there will be a n excessive action on t h e organic matter is subject t o t h e same great source of error, viz., t h e with consequent liberation of carbon dioxide not de- presence oE substances supposedly neutral t o phenolrived from carbonates, necessitating a blank de- phthalein, b u t through hydrolysis, alkaline t o t h a t termination on a n extracted sample a n d t h e applica- indicator-sodium bicarbonate in t h e one case a n d tion of a correction for carbon from organic sources barium carbonate in t h e other. which involves considerable uncertainty. For t h e reasons enumerated above, it is evident There is, however, a source of error in t h e Marr t h a t absorption in barium hydroxide solution a n d method if t h e double titration procedure is used for titration of t h e residual hydroxide offers only a slight determining t h e evolved carbon dioxide. This is advantage over t h e older scheme of absorption i n indicated b y t h e fact t h a t t h e results b y t h e Marr sodium hydroxide a n d double titration on t h e score method, although showing excellent agreement with of accuracy of results, although it does offer some adthose obtained b y boiling with stronger acid, t h e vantages in t h e points of speed and convenience. proper correction being applied a n d t h e double t i t r a - By careful standardization of t h e method, it would tion procedure used in each case, do not show such dpubtless give satisfactory results for routine work. good agreement when compared with results obtained The filtration method proposed b y Cain is not subby boiling a t atmospheric pressure and measuring ject t o t h e above sources of error, a n d should give t h e carbon dioxide gas, t h e correspondiflg correction SUMMARY
1 2
3
Jour. Agr. Sczence, [2] 3, 155 Phzl. Trans. ( B ) , 193 (1900), 289. THE JOURNAL, 4 (1912). 611.
1 Technologzcal Paper 33, Bureau of Standards, also THISJ O C R N A L , 6 (1914). 465. * THISJOCRNAL, 7 (1915), 1045. 3 Ibid.. 6 (1914), 843.
T H E J O C R S A L O F I l l - D C S T R I A L ALVD E Y G I S E E R I S G C H E M I S T R Y
4-28
very accurate results when properly carried out. While not so speedy as t h e simple titration, its freedom f r o m t h e usual sources of error entitle it t o the preference for all exact work. I n Table I are presented results obtained by several methods on a series of six soils. identical m-ith those supplied b y t h e Referee on Soils of the Association of Official Agricultural Chemists for cooperative work in 191j . The figures in parenthesis following sample No. I serve as an approximate measure of t h e extent t o which organic matter has been attacked hy t h e reagents in each case, and these percentages have been deducted in the cases of t h e next three samples in order t o afford a better comparison between methods. A similar blank for Nos. j and 6 was obtained b y extracting a sample of S o . 5 v i t h cold dilute hydrochloric acid ( I volume concentrated acid diluted t o I O , t h e same as used for those methods requiring boiling a t atmospheric pressure), then washing thoroughly with COi-free r a t e r . o.ooyy per cent carbon was obtained from t h e extracted soil b y boiling and estimation by double titration, while none whatever was obtained b y t h e LIarr method in either of two TABLE I-PERCENTAGES CARBOXB Y T'ARIOUS METHODS SAMPLES ANALYZED Loam, deficient in Organic M a t t e r a n d supposedly free from Carbonates 2-Xo. 1 a small a m o u n t of 100 mesh Limestone 3-No. 1 100 mesh Dolomite &No. 1 100 mesh Dolomite 5-Black Clay L o a m , containing Carbonates and much Grit (meventing fine grinding) 6-Ko. 5 100 mesh Dolomite RESULTSBY MARRMETHOD(MODIFIED) Boiled a t Atmospheric (BrownPressure with 1 : 10 HCI (Cain's) Residual Escomhe) Double GasoBaCOs Ba(0H)z Double No. Titration metric Titrated Titrated Titration (0,0018) (0.0007) (0,0015) 1 (0.0096) (0,0093) 0.0276 0,0291 0.0274 2 0.0276 0,0276 0.0289 0 0279 0.0270 3 0,0276 0.0280 0 . 2 2 0 4 0.2194 0.2237 4 0,2133 0.2220 0.1454 0,1498 0,1462 j 0,1485 0.1508 0.2759 0.2868 0 . 2 i 5 0 6 0.2835 0.2880 1-Silt
+++ +
trials. I n this connection it is b u t fair t o state t h a t only one other analyst reported no carbon b y t h e Marr method from No. j after extraction, but, on t h e other h a n d , only one reported more from No. j after extraction t h a n from S o . I , although S o . j contains by far t h e larger amount of organic matter. The explanation may be either t h a t KO. I actually contains a trace of carbon dioxide. or t h a t extraction with cold dilute acid removes or causes the decomposition of the most readily attacked part of t h e organic matter. I t was noted t h a t the acid extract from No. j ITas 1-ery dark in color: I n conclusion, t h e writer wishes t o express his ohligations t o hlr. J . W , Ames, chief of the Department of Chemistry a t this Station, for helpful suggestions and permission t o publish this article. EXPERIMEXT STATIOX WOOSTER, OHIO
OHIO AGRICULTURlL
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SOME NOTES ON SANDALWOOD, ITS ASSAY, YlELD OF OIL, AND CHANGES I N T H E OIL DURING DISTILLATION1 By
c.
11.
BRiGG5
Received September 13, 1915
The d a t a set forth in this paper have been collected a t various times during t h e last few years, and as 1 Presented at t h e 51st Meeting of t h e American Chemical Society, Seattle, Aog. 31-Sept. 3, 1915.
1-01,
6 , No. 5
similar results have not been noted elsewhere in t h e literature, it vias thought it might be of interest t o others. A few years ago twelve samples of various grades of sandalwood were obtained from the hlysore Province. India. These samples consisted of small pieces of the unground wood representing certain types or classes of sandalwood which could be bought from the h>Iysorc government. The samples varied in weight from a few ounces t o a pound, and as there was a Considerable range of prices. we \\-ere naturally much interested in t h e content of santal oil in t h e different grades. X search of t h e literature failed t o reveal any method of assay for the amount of santal oil in sandalwood t h a t could be applied t o these small samples. At first it was thought t h a t this problem was hopeless, but after considerable experimentation a method of assay was evolved which proved t o be quite satisfactory. I t is as follows: Place I O O g. of the finely powdered drug in a Soxhlet extractor and extract with sulfuric ether for one d a y or until completely extracted. Transfer t h e ether extract t o a 200-cc. side neck distillation flask and evaporate off the ether on a steam b a t h with t h e aid of a stream of air. Add 3 j cc. of glycerine and distill in a vacuum until about z j cc. of the glycerine have distilled over. Add z j cc. of water t o the distillate and extract with chloroform, using three portions of about 2 5 cc. each. Evaporate the combined chloroform extracts in a tared dish on a water b a t h with the aid of a stream of air until the chloroform has all been removed, dry in a vacuum desiccator over sulfuric acid and weigh. Sandalwood contains a large amount of fixed oils as well as t h e essential oil and both are extracted b y ether. The essential oil cannot be separated quantitatively from this extract b y distillation in a vacuum unless glycerine is also added t o help carry over t h e last traces of t h e essential oil. The essential oil can he separated from t h e glycerine in t h e distillate by extracting v i t h chloroform. X j-g. sample of santal oil was dissolved i n ether a n d assayed b y the a b o r e method as a check: practically all of t h e oil was recovered. T h e twelve samples of sandalwood obtained from t h e Mysore government and representing as many different grades assayed as follows: To. h-0. yc OIL S O . 5 OIL I
2 3 4
3.7 i.44 5.9 8.3
5 6
3.7 6.5
7
4 7
s
i:73
12
3.84 3.53 3.66 3.8
SAMPI,E FROM STOCK, 6.0% Oil
I t will be noted t h a t these samples varied from 3 7 t o 8.3 per cent. I t would be of much value t o distillers of santal oil if t h e cost of the wood could be based on t h e content of oil, b u t t h e commercial conditions governing t h e sale of sandalwood are such t h a t this cannot be carried out successfully. H o w ever. t h e assay is of r a l u e in checking t h e yield of santal oil from t h e wood when distilled on a large scale CHASG$S
IS T H E O I L DURITG D I S T I L L A T I O X
During t h e course of this work, it was noted t h a t oil obtained from sandalwood b y this method of assay had a n optical rotation of --18' or above, whereas
