countcred by Tuller and Xeiding (6) in their work with carbohydrates in the presence of proteins. Cysteine rcduces the intensity of the uronic acid color d t ~ e l o p e dby heating for 20 minutes at i o o . In the case of glucuronic, acid, this reduction amounted to 10% when the concentration of both reactants was between 100 and 200 y per 0 ml. Two experiments conducted with ryst.eine and glucuronic acid at 100" indicated that at this temperature cyst,eine caused a measurable amount of color cnharmment rather than color !oss . As a spot check for significant higher order interactions when more than one :imino acid is present, tryptophan, methionine, and cysteine in the presence of glucuronic acid, mannurone, and idiirone, respectively, have been ex:imined at 70" employing 2' factorial tlcsigns (1). Analyses of variance of t h r data indicate that none of the inter:ictions above first order is signifitaantl\. large in ternis of the residual or clsptxriiiwiital crror. :\'one of the amino acids stutlicd other than tryptophan, mc.thionint1, :ind cystc>inecithrr protluws an niithi.onc cdor of its own or has a nieasurablt. influencat. on the anthrone color of the uronic acids. The present findings indicate that the vstiniation of uronic acids with anthrone i n the presence of amino acids or proteins 1 1 1 : ~be ~ tlifficult,. part,icularly for sniall :imounts of :t uronic acid in the pres( w e of larg(. :tniounts of amino acids.
.
with tlcw-casing concentram Consequentlv, by using a htiatiug temperature near 70" and by -uitat)iy reducing the concentration of the sample, aniino acid interference in some cases can be effectivc.l\- eliminated, ACKNOWLEDGMENT
0.080
0
80 Conc. Methionine,
160 J
'6ml.
Tlic authors are indebted to 11. L. IYolfroni for specimens of D-niannuronr and 12-0-isopropylidrne-L-idrii ono-ylactolie, to Philip Hoffman for a specimen of ~)-niannurone,and to F. G. Fischcr for a specimeli of L-guluronrL. The!. gratcfully acknowledge the assistr a w e of I,. C. Massopust in preparing the dranings and photographs and of Waldcnier Rosenthal in rarrying out part of thc esperimriital work.
Figure 3. Absorbance of various concentrations of methionine and glucuronic acid G A 200 = glucuronic acid, 200 7/6 ml.
However, when the aniount.e of a uronic acid and amino acids are more nearly alike, the follov ing observations may be utilized to reduce t.he interference of the latter. First. the rfftvts of t'ryptophan. methionine, :tiid (.ystcinr ( i i i terms of absorbance) d o c w : i s c L siil)rtantially as the heat'ing tcmpcraturt, is rtduccd from 100" to i o o ; under the siimc conditions the absorbances of all the uronic acids increase. Second, the nonadrMive effects of the methionine and (,!.stvine diminish
Ana IyticaI Study of Aminoethyl Vinyl Ethe r System Based on Counte rcurre nt Extracti o n lSADORE ROSENTHAL, FRANCIS JACKSON, and WARREN WATANABE Rohm & Haas Co., Philadelphia, Pa.
b Conventional methods of analysis applied to aminomethyl vinyl ether {vinyl and base) give a misleading impression as to the purity of the material. It is possible for this compound to disproportionate to form impurities that have the same ratio of vinyl ether to base as the starting material. The system was investigated by countercurrent extraction on a Craig machine and the impurities were isolated. Schiff bases and ethanolamine were identified. A short analytical method based on extraction was developed. The results obtained with a combination of iodine-hydroxylamine-base analysis are discussed. 1702
ANALYTICAL CHEMISTRY
I
s >EPARATIO~-S ~ O R K on nniinoethyl vinyl ether it was found that aminoethyl vinyl ether, H?C=CH-O-CH:CH2-SH2 (AEI'E) (I1 or Rand 11) prepared by certain nwthods contains two principal inipuritirs: cthanolamine, (E.4) (I or Band HO-CH2--CHz-SH2 I), and the Schiff base of AEVE, HzC=CH-O-CH?-CHz-S=CHCH, (I11or Band 111). Chemical analysis of samples by vinyl analysis Imodified Siggia hydroxylamine method (2))jand/or titration of amine groups is of no value in this case, because the impurities are often produced in such proportions that anaiytical values on mixtures are always close to the theoretical values for pure AEVE. For
(~siinipl(~, typical anaiyses on three s ~ n i -
I) did not agree with the \xlu(~sohtaincd by countercurrent cstrwtion (Figurc 1). 011tlw basis of amine and vinyl dott~niiii:ttion done, the samples appear to 1 i a . i thc ~ correct anal~.sis. Moreover, the wtio of amine to Tiny1 is closely 1 to 1, as expected. Tet examination of the results obtained by countercurrent cstractions shows a wide variarinn in the actual coniposition of the samples, Countercurrent estractions of the order of 30 to 40 transfers are tedious, and a simpler analytical method is desirable. The method described here consists of extracting the ethanolamine ~ ) i t h s (Table
qua nt.itati\-ely and determining thc aniourit by titration. This d u e . together with a vinyl and aniine deterniination on the unfractionatetl sample. allo\\-s the concentration of the other components to he calculated. -1threetube esqraction is sufficient for separation of the ethanolanline froni the other tn-o components. This type of iipproach can be applied to sinuiar aniinoether systens. though of necessity differing in detail. If the Schiff base of ethanolanline is present. it might hc tlrti~riiiined in addition to the ot.her thrrr com~wnents. Though this procedure ir-orketl weli in practice. the possibility of appl!-ing an iotionietric method ( 3 ) to conipltment the h!-drosylaniine and titrstioii nitdiMIS was also inrr.~tignterl. Tliv rc.+tlit of this combination of nic>tho& \\-ai encouraging but not SO good 3.; t h t o1it:iiiied by extraction.
Table 1.
Comparison of Analysis of A W E Samples by Chemical and Extraction Techniques S i r c ~ .wr Gram
Estrsrtioii
Samplr ;t.
B
c Theov- for .\E\-El. meq. per gmni
Eh,
Chcmical dniine \lnyl
Band L 11' 2 6 4s
11 -I 11 4 11 3
11.4 11.5 11 4
11.48
11 .48
R:wd I I
IE\-E.
.\E\-E. Band III'
8 9 5 3 '10
3 2 4 3
1 1
Figure 1 . Fortytransfer distribution of crude AEVE s a m p i e using methylene chlor i d e w a t e r system
EXPERIMENTAL
Tht. iull countercurrent est rnct ions wrc. tlone on P 30-tube Post Co. Craig niachitie. The tube x-olunies were 100 nil. for path phase; 5- or l0-grnni sanipirs were used. The results on tlic partiuli?- resolved hands were calcul::ted rising binonlial coefficients ( 1 . 4 ) rather than the nornial error function. I-se of the nornul error function can lrarl to swioiis errors in citlculation oi :I sm111 hand such as 111 tlist is onl>- piirti:illy resolved froin :I much largclr I ~ i i t i d . especially at high or Ion- h- value3 (h-
is the partit.ion coefficient). The c\xperimental points were fit 1)- 1e:iat. squnrrto achieve the best fit with n wries of binomial coefficients correapontling to :I giwn p n-here p = 1 and /I 4 = A. 0 1 l c ~a p v a l ~ e\\-as rhosen. thcs :i\-(*ragi& quotient of the resolred c~spc~riiiiental points tlividerl by thc corrt~ipon~ling binomial coefficients was wc~lto pi\-(. total Iiand content. This W:I. ciiec.krri 1))- using wnimatioii tablts ( 1 ) . Oncr :I I - B ~ ~for C the large one of tlic. uiirwol\-trl pi.alr* was obtained? correction factor:: \ w w available for the snlalk~r hand. In some cave where the hand ratio3 w r e not too great, the e n d l e r band could he calculated direct.ly. as the eorrvctions were small. This offered a check on the indirect calculation and rrsuits by hoth niethocis agreed. showing that there was little intrr:ictioti.
+
ANALYTICAL METHOD
Scope. This method is suitabir for the analysis of aniinoethpl vinyl ether sample5 containing only thti Schiff base o f the ether and etliniiolaniizie a s impurities. TOM i-inyi ant1 base content are detertiiined by titration on the origiiisl sample and ethanolamine is i2olated by estrartion and determined by titratioii. Procedure. TOTAL VrxTL GROCP.': A S ACETALDEHYDE (9). Keigh about 10 meq. of sample into a citrate bott.le. add 10 ml. of water and 2 drops of
TUBE NUYBER
I?roinocrr-ol p r i w indicator: a i d titrate t o the etitl point with G.5.\- h>-tlrochloric ndtl jo nil. of 0.5.1acid. Itiin~t~ili:itt~ly hydrosylaminc h ydroch loride (aqueous), cap t.he bottle tiglitly. and heat for 2 hours a t 8.5' C'. Then cool t o rooni teniperaturt. and titratr with &.?I-\ .sodiuni h ydrosiilc.. TOTALBA-E. Weigh a 0.3- to O.3%grani saiiiplt~into an Erlenniryr flask. disaolw in 30 nil. of water: antl titrate to tiw broniocrt~aol green end point with 0.I.\- h!-drorl~loric arid. ETI-L\SOL.IWSE BY SHORT ESTRACTIOS METHOD. Set up a rack coutaining three 20O-nil. separator? funnel:: (labeled 1. 2. 3. left t o right). and fill S o . 2 and So. 3 n-itli jo nil. of distilled water containing 10To by weight. of sodiuni chlorirl(~. Weigli out :t :%-gram sample of tlir. nkr%urr t o IM, atl;rlyzc*ti and dissoi\-c. it in 25 1111. of tlistillcd wstrr containing 10yc by weight of sodium chloride. Place the staniplc solution in funnel I , rinsing it in with anotlicr 23 nil. of water , ail material in tube 1 in excess of that expected based on the contents of tube 0 can be presumed to be a different material. This is the basis for determning the minimum unknown content for Table IV. It is a minimum figure because t.here should be additional amounts of it in tube 0.
The higher distillation cuts were taken through the short ext.raction proceduw :ind the aqueous layers examined fat, vinyl content by the hydroxylaminc~ niethwl. Vinyl unsaturation \vas found in significant amounts, but not. enough t,o a.ccount’for the shift in the solubility propthes of the ethanolamine band. Typical dat,a are given in Table IT’. It can be seen. therefore, that while t’irerc, is definitc evidence for vinyl functionality in tlw Band I material from the higher cwt.si: it is not enough to explain the distrihtion shift. Actuall!. the amount of this unknon-n material is rxtrrnidj- small u l i t w the AEW, misturcl is considtwci :IS N \\-hole. The sodiunr chloritle is added to facilitate separation of the phases during vstraction. The procedure ca.n be used in its absrnw; if desired, as the emulsion problem is not too serious. The 1 ml. of 0.l.V sodium hydroxidc is added to supprrss hydrolysis of thv aminoethyi vinyl rther. As long as some ethanolmiinc is present thv hydrolysis seems to br supprrsscd. Hon-ever, in tlw roursc of thv rsrtrnc.tion. the hulk of t,ho
c%iianolamineis reniovtkd i n tubes 1 and 2 and the aniinortliyl vinyl ether appears to hydrolyze to a small rxtent. If SchifF bases of ethanolamine arc present, they would appear in Band I. This situation might be handled by dividing the watw layers ( 1 , 2, and 3) iwnaining after t.hc short extraction procedure into two, i d performing a vinyl titration on one aliquot and a base titration on thr other. PreliminarJ- work has he11 done on the possible analysis of this threecoiiiponcnt system by use of a n iodometric nictliod (3) for vinyl ether together with the hydroxylamine and total base nicstliod. Becsausc such work m y not lw continued iii this laboratory, typical rwults obtained to date on samples analyzed by the other two procedures :ire worth examining (Table V). The method of analysis is based on thr assumption that the hydroxylamine nithhod gives total doul.ilc bonds, the iodinc niethod (S) gives only vinyl ether linkages, a.nd t,h(. h s c titration gives total base. Unfortunatcly, t,hc iodin(, method
without niodification seems to rc!sult in partial attack of the --C=NH linkagcl and a resultant high value for AEVi; contcnt (Sample 2 ) . This sick: reaction \vould be of increasrd inil’ortancc as the relative amount of Schiff base increasrs. Changing rrartion conditions niay suppress this, but at present the only safe intrrprchtion to make concerning t.hc iodin(, nii:thod is that if i: is not equivalent to the hydroxylaniinc valuc, t,he sample is of doubtful purity. The reverst nrrd not ncwss:rriiy fioltl.
Determination of Particulate Matter in Concentrated AerosoIs Application to Analysis of Cigarette Smoke W. B. WARTMAN, Jr., E. C. COGBILL, and E. S. HARLOW Department of Research and Development, The American Tobacco Co., Richmond, ‘/a.
b A glass fiber filter material, Cambridge filter medium CM-1 13, may be used for the collection of the particulate matter in concentrated smoke aerosols. This material has a high loading capacity, permitting the collection of a sample of sufficient size to be assayed by macrotechniques. A procedure using these filters for the quantitative collection of the particulate phase of cigarette smoke is rapid and reproducible with a precision to better than 2%. The coilected smoke solids may be extracted from the filters for the determination of nicotine or other constituents.
F
is the most convenient technique for routine sampling of the particulate matter in aerosols. For relatively dilute aerosols, filters of paper and molecular filter membranes are satisfactory. These are of low capacity, however, and require the use of micrntechniques for assay. ILTRATIOK
(’igarette snioke is a dense aerosol, the particulate phase of which consists almost entirely of semisolid particles; to collect a sufficient sample for macroanalysis, a filter of high loading capacity is needed. Tubes packed with glass wool, asbestos, or pol\ dcred cellulose may he used, but all sucli filtering materials have inherent disadvantages, and it is tliffidt to pack columns with consistently reproducible filtration efficiencies. For routine smokv analysis a filtering mcdium is needed \I hich will effectively retain particulatv pliase snioke a t rooin tempcraturc, is nonhygroscopic, and is rasily fashioned into filters of uniform efficiency and convenient size with a minimum of preparation on the part of the user. Touey (IO) used an asbestos-inipregnated paper filter disk to separate thc particulate phasr of cigarette smok(, prior to analysis of the gaseous phase. He reported that thr filter removed over 99% of smoke particulatm. By an adaptation of this terhniqiic the authors
Iiavcb developed :t mrthod for tlir tlctrrinination of the total solids (total particw1:itr.s) in cigarvttr smokv. A glass fiber filtcr medium. (‘anibridgcb filkr mcdiuni S o . CAI-113 (Cumhridgch Filter Corp., Syracusr, S . E .). mcrts tlie requirrnirnts for quantitative collection. It is availablc in sheet form about 1.5 mm. thick. Disks inscrtrd in holders of suitable design arc cffertivc traps for thr collection and n-eighing of particulate phase smokr. After thr filter disks with the collectrd smokr solids have been wighcd, they can br renioyed from the holders and cstractcd for clotermination of nicotincb or othrr constiturnts of the smoke. -4filter was desired which could collwt tlw smoke of a t least fire cigarettes a d he snlall enough for easy handling in n-cighing and the subsequent extraction of the particulate smoke for analysis. A disk with cbffcctivc filtering dianivter of 1.5 inches wa5 adopted. To permit the smoking of a t Icast five cigarettr. of am^ type through R single
