(6’72) 1-aryas, V. H., Cozzi, G . Y.,Peralta, O., -linieridariz, R., Rei. ni4d Chile 84,
546 (1956). (673) Vella, F., P i o c Alzomzz Assoc X a l c y a 9, S o . 3 , (December 1956). (674) S’elu. P.. T’elu. 31.. -1nn. b ~ o l clzn . ( P a ~ z s 14, ) 676 (1956). (675) I b i d , 15, 89 (1957,. (676) Ibzd p 231. (677) S’entuia, S.,Candiira. F., Haeniotoloazcal 1Pazza) 41. 351 11956). (Si@ S’erghehe, S.; J . hlzn. Pathol. 11, 191 (1958). (679) Verghrse, S . , Ramakrishnari, 1’. S . .Ihzd., 10, 104 (1957). (680) Vermeulen, .A,. d c t a Endoc) inol. 26, 390 11957). (681) Von Euler. U. S.. Czba Fozindatzo7i Colloq. o n Endrocrinol. 11, 379 (1957). (682) Ton Euler, U.S.,Floding, I., Scand. J . Clzn. & Lab. I n i e s t . 8,288 (1956). (6831 Kaalkes, T. P., Udenfriend, S., J . Lab. Clzn. -\led. SO. 733 (1957). 1681) Warner. H.. Acta Endocrinol. ~
I~
S u t u r e 181, 1475 (1958). (687) Webb, J AI., J . Bzol Chem 230, 1023 (1958) (688) Kebb, J h1 Levi, H. B X e t h o d s of Bzochem Anal 6, l(1958). 1689) Keeke A.. A c t a Endociznol. Szivwl. .. ’ 31,41 (1957). (690) Keichselbaum, T. E., hlargraf, H. IT.. J . Clin.Endocrinol. and dletaholism 17, 959 (1957). ~
Review qf APPLIED ANALYSIS
T
~
~
(699) We&y-H&dzija. B., Abaffy. F., Acta Phaim. Jzigosloz. 7 , 137 (1957). (700) Khite, D.. Haidar, G. A , , Reinhold. J. G., Clzn. Cheni. 4, 211 (1958). (701) Whitehead, J. K., Bzochein. J . 68, 653 (1958). (702) Kieland, O., Bzochem. Z . 329, 568 (1958). (703) Wilkinson, R. H.. J . C l i n . Pathol. 10, 126 (1957). (’704) Williams, I,. A , , Linn, R . A , , Zak, B.. Clzn. Chzrn. A c t a 3 . 169 (1958). (705) Williams. L. A . , ’Zak, ‘B.>A n i . J . C l i n . Pathol. 28, 195 (1957). (706) Wilson, H., Borris, J. J., Garrison, 31. M., J . Clzn. Endocrinol. and N e tabolism 18, 643 (1958). (707) With, T. K., Scand. J . Clzn. & Lab. Incest. 10, 186 (1958). (708) Wootton, I. D. P., Clzn. Chem. 3, 401 (1957).
( T O 9 1 \Yotiz, H. H., Lemon, H. l I a r c u s , l’.. J . C l i n . Endooinol. dletabolisni 17, 116 (1957). (710) TYotiz. H. H., Lemon, H. AIarciia, P., Savard, K., Ibid., 17,
AI.! and
AI.,
534 (1957). ( i l l ) \Yr6blewk!: F.! ”-1dvances in Clinical Chemistry, ’ Sobotka, H., Stewart, C. I’.. ede., vol. 1, p. 314> A4c:idemic Press, S e i v Tork, 1958. (7121 TVr6bleivski, F., Cabaud, P., Ani. J . Clin. Pathol. 27, 235 (1957). (713) \Yurm, A l . > Epstein, F. H . , Clin. Cheni.2 , 303 (1956). (711) M7iirni, AI., Straus, R., A m . J . C l i n . Pathol. 27, 691 (1957). (715) Tnrbro, C. L., Golbj-, R. AXAL. CHEJI.30. 504 i1958). (716) Toe, J . H..‘Ibzd., 29, 1246 (1957). (717) Tonan, V. L., Reinhold, J. G . , C l i n . Chern. 3 , 685 (1957). (718) Yudaev, K. A . , Pankov, T u . A . , P ~ o b l e n iEndokrznol. ~ z Gormonoterap. 4.35 11958). (716) Zacco, 11.)Dalfino, G.. Pacilio, I-.> Folza Endocrznol. ( P z s a ) 10, 269 (1957). (i20) Zahn, H., Marstaller, H., 2. Physzol. Chein., Hoppe-Seyler’s 310, 44 (1958). 1721) Zak. B.. Am. J . Clin. Pathol. 27. 583 (1957). (722) Zak, B., Sun, K. AI.>Ibid., 29, 69 (1958). (7233) Zelnicek, E., Scripta M e d . Fac. X e d . C‘nio. B r u n e n s i s et Palackyanae 30, 291 (1957). (724) Zelnicek. E.. Cernoch. K.. &sovts ICkdrzi c‘esk$ch 97, 188 (1958). (725) Zijlstra, IS’. G., Muller> C. J., Clin. Chini. Acta 2 , 237 (1957).
COATlNGS M . H. S w a n n , M . L. A d a m s , and G. G. Esposifo Aberdeen Prouing Ground, illd.
biennial review covers the period from October 1956 and repre. sents the authors’ choice of the importa n t contributions in coating analysis. It is hoped that, in an attempt to be selective. commendable publications have not been omitted. Other reviews of a similar nature ha\e appearrd in this period (&$-66), in addition to a review i~ hich concerns only tlic analysis of vinyl and acrylate polymer. (I?). Comprehenfive treatment of the subject is found in %: chapter by Shreve (45) and s book by Hunimel (28). In the former. proiision is made for the coniplete analysis of organic coating materials, using a systematic set trf detailed procedures. 11-ith emphasis on the more important resins such as alkyds, nitrogen, and phenolic resins. The various techniques such as infrared and ultraviolet spectroscopy, chemical analysis. polarography. and nonaqueous titrinictry are also described with notations of thc advantagesand liniitationsof each. Hummcl’s vork (28) is divided into HIS
674
(691) TYeigel, I\-.>Fette. Sezjen. A n s t , Tdimzttel58, 3038(1956). (692) \Teigel, I\-., Pharniazze 12, 612 (1957). 1693) Keill, C. E.. Bedekiari. Armand. Aficrochem. J . 1. 89 (1957). (694) Weil-IIalhe~~e, ‘H.> Bone, A . D., Biochem. J . 67, 65 (1957). (695) Keil-IIalherbe, H., Bone, d. D., J . C l i n . Pathol. 10, 138 (1957). (696) Keinmann, S. H., Jayle, AI. F., Bull. soc. chiin. bioi. 39, 65 (1957). (697) Weissbach, I*., Waalkes: T. P., Gndenfriend, S.! J . Biol. Cheiii. 230, 865 (1958). 1698) Keissman. II., Klein. B.. Clin.
ANALYTICAL CHEMISTRY
seven parts and covers infrared preparation techniques and documentation. physical methods of identifying large molecules, chemical reactions of groups. identification of oils, resins and plasticizers, and specific examples of teclinical analysis. GENERAL ANALYTICAL SCHEMES
In a separate publication, Humniel (29) describes a systematic plan for the infrared identification of 10 classes of plastic materials and lacquers. The application of infrared spectroscopy t o the study of the chemistry of drying oils. the curing of epoxy resins, and the identification of synthetic resins, were discussed by O’iYeill and Cole ( 5 3 ) . 113erley, Spragur, and Campbell (87) deIreloped quantitative methods for the analysis of solid poly(vm~-lchlorideLacetste) copolymcrs, using potassium thiocyanate in potassium bromide a5 an internal standard. The carbonyl band a t 5.8 microns x i s usrd for the quantitative measurement of the acctatr con-
tent. Free fatty acids in aluminum soaps n ere determined by the same method. Ahlers (3) has concluded a series of papers discussing applications of Fpectrophotometry in the analysis of coating materia!s. The concluding paper discusses the identification of styrene interpolymers, modifying resins in alkyd resins. and pentaerythritol a? the acetntc,. The use of Raman spectrophotometry for clarifying the structure of resin acids. fatty acids, oils, and poly(iiirthj 1 methacrylate) is included, with a disriission of the principles and adiantages of flame photometry in coating analysi.. JIurplij- and Schwemer (49)applied infrartd spectroscopy to the rapid qualitatix-e drternmination of n ax, resin, and emulsifier in emulsion polishes and present spectra of the common components including a group of amine emulsifiers as their Iiydrochloride derivatives. Szyniaiiski and Conley (76) have contributed a method and described the apparstu; for rcmoling varnish and en-
ani('1 filiiii c,lf,c,trrilytically from copper p1ntc.s for 11s: iii curing and aging studivs by inirared analysis. Appropriate filni tliiclinessea needed to eliniinate fringe. pattcwis :ire also dcscribed. H:isl:ini :riitl Squirrrll (27) discuss and giv(3 tic~t:iil(~d l~rcicediirc~~ for thc applic~ition(if niitoiiiatic titriiiictry to the d~'tc.rniin:itiiiiirif nitrog;c,n arid chlorine in pol>x~ors.tlctrrtion of tcrephtlinlic :wid in pcil?-(-tws by aniinolysis, and ili~tc~riiiiii:itioii of :iitlrhydes and ketones i n m-I:itc nionorntxr.
SPECIFIC CLASSES OF HIGH POLYMERS ;lii :in:~l>~ti(~:il sclienir anti indi~-idual confirniatorj. tcAsts for macromolecular siIhstnnw+in :iqurous solutions are prcscnt'td hy R(k1ilicrzer (57). Included arc soluhle iii,ea-fornialdchydc polynicrs. metli~~lcellulosr, poly(acry1ic arid), poly(Yiny1 alcohol), poly(viny1 nicth>.l cdier). and sodium carhoxymc~tliylcc~llulose. Poly(vinj-1acet,al) resins arc' rlctectcd by Zanibrini (90) through :i qc'rics of tests including solul d i t y , clc~nic~rital naalysis, saponification nunihcr. dctcction of formaldehyde. and the approsiiiiation of acetal and hydroxyl groupq. {-sing tetramethyl and tc%rabut>-lniiinioniuni salts as supporting elcctrol>-tcs. I-sanii (82) drterm i n d ~-iii>-Inwtatt', butyrate. and benzoatc ~ ~ ~ ~ l a r o ~ r : i p l i i c aThc l l y . polarographic' i,c&ic.tion of vinyl acetate \vas also stiitlictl in nic~thaiiol containing nicrcuric* :icetnte. sodium nitrate. xiid thymol hliic,. dtyrrne, aerj-lonitrilc. :ind c u - i ~ i i ~ t l i j ~ l ~ twy ~r ~ c ~dr+riiiined iic clire,ctly :iiirl rresins by i n f r a r ~ d sl)cctroljliotoiiit~tr~is givcn by Schneebcli and T.alau-Keraly (69). Considera t i m is t.iwii to coiidcnsatcs of a numbrr of c1i:icitls and diols. Taivn :ind AIaj- (79) applicd paper clironi:itogrnpliy of polyols and dicar110sylic :icids to the analysis of alk!d wsini;. Tlic dicarbosylic acids are iso1:ited first thrcugh saponification. the kitty acids ;cparated with ion exchange rcsins. and the polyols rccnvered from
the eluate. This u.ork n-as practicnllv duplicated by Arendt and Schenck (4) including identification of seven acids and eight glj-cole. d rapid, quantitative drtt~rii;ination of polystyrcne in oils, alkyds. and epoxy resin esters by infrared absorption is described by Frasrr and Pross ( 2 2 ) . The d a h indicat'e acwpt:iblr nccuracy in most of the analvscs, \Jut in sonic systenis analj-zcd. onls 90% of tlir polystj-rciie could bc accounted for. The authors attrihutcd thc, IOK r('sultj to the prcscnce of styrene niononicr lost n.hen thc films n w e dried. Qunntitative measurenitnt of pslyacr!-lonitrilc, ('0polynicrized n-ith styrme or butar'icne, by infrared spectrometry has also been described in detail (2). The analysis is made on resin solutions ivithout solvent rcnioi-a1 and absorbances n-ere calculated by a variation of the base-line techniqur,. A coniparison (80) n-as macle of the ultraviolet' and infrared spectra of some high polymer acrylic derivatives and their mrresponding monomers. Acrylonitrile has been measured volumttricnlly (SO) by reaction with sodium sulfite in anhydrous dioxane and titration of the sodium liydroxide formed n i t h standard acid. D(hviation from k n o m composition is c~lainicd to be lcss than 0.27, by this nwtliod. 1Icthods for analyzing aniino-fornialdehyde rcsins h a r e been reviewed by 1Ioratli and Koods (48)n-ith detailed procedurvs givcn in man!- cases. The review concerns such componrnts as urea, melamine. thiourea. total and free formaldehyde, total and free nicthanol, methylol, and niethylatcd anti methylenic formaldrhyde. Some of the procedures for analyzing urca-fornialdehyde rcsins w r e critically evaluatcd by S t d l and S'asta (62), Ivho studied the resistance of functional groups against alkaline and acid clclavage during the estimation of methylol grcups. Zaljrodkin (89)w e d an Abbb-type refrac$onieter to dctcvmiinc concrntrations in the case of urea-formaldeli\-de resins and alcohol or n-atcr solutions of plicnolic rcsins. Nethods for tlie determination of iirea and melamine in niixtures of thcir formaldehydr condensation products arc recommendcd by Vidnicr (%), ~ v h odeterniincd urea as dilirnzj-lima by aminolysis with benzylamirie. l k h mine 'vas determined as niclarninc picrate. An accuracy of 90% n-as reported. AIelaniine-fornialcleliyde coating rcsins in modificd alkyds arid othcr resin combinations arc detcriiiined gravimetrically by acid hydrolysis in dioxane ( 7 4 ) . Trea resins interfere in this method unless n i e a s u r d by :i aepnro te technique aft'er which a corrrction can he niadc. Feipl (IS) has provided a rapid. sensitive yualit'atire test for urea rcsins. based on the formation of tlie 1-iolet nickel salt' of diphcnylcarbazide applied to a fciv milligranir of resin ~ l i i c l ihas
been hydrolj-zcd n-ith miccwtratcd hydrochloric acid. Other qualitatiye tests (73) usctl Ehrlich's rengcnt, t o identify urea. inelaniiiic, isocyanate, and urcthnn rvsiiiF. were developed for applicxtioii to coatings in general and u r w n i i i i nielaniine resins ivi~re d(~tcc.tetlsiniultancously. In tlie sariie pulilication, :i rapid group test was outlincd for tletectinq nitrogen, silicon, pliospliorur, and titanium in coating matcriak. iollon-in:! acid digcstion hy a rnicr~tccliiiic~ut~. -1 recent puhlication (72) tlcscribrs a spot tezt for 1)isphcnoLtypc rposy !wins in solution or filni; n-itli :I test for distinguishing hctwwn rpoxy rwiii, t c d for cellulose and dcriwtivcs on th(. formntion and detection of furfural with aniline acetate whcn the sample is tliermallj. decomposed in concentrated phosphoric acid. Furfural resins ~ v o u l dproljably iiitrrfere. A nen- color rc~actioii n-ith c~llulosr,its ethers and estcm ~ x i q reported (8). The suhstancr, is n.armed n-itli 1 ml. of benzene and 1 nil. of conrentratcd (8 to 1) sulfuric acid for 1 or 2 niinut,es and 1 or 2 nil. of ethyl alcolioi are added. Intense green or blutl colors form n.itli cellulose, cellulose nitrate, acetat,e, acetate-butyrat'c, methylcellulose, and carboxymethylcellulosr ; ethylcellulose produces a violet color. Sanisel and Aldrich (58) modified the anthrone test to determine ver>- sniall amounts of ethylcellulose and cellulose acetate-butyrate in nonaqueous nicdia wit'liout intcrferencc from fats, oils. or glycols. The same reagent has bcrn applied ( 7 1 ) t,o thc d($criiiination of cellulose ethers and esters in a variety of coating compositions ~ i i t h n u ti1itt.rfercncc from plasticizers or other resins n.ith thc exccption of nitroc~~llulosc. The yellon- color formed I)>- tlic rcaction of nitrocellulose with alkali iii tlic prc.sr~ucc of acctonc has I J C C ~ I uscd (70) as thr basis for a simple. rapid nic.thod for analyzing lacquers directly for tlirir nitrorellulose contclnt. Lintler and Persson (40) rerisrd their original method for deterniiniiig rosin acids in mixture v i t h fatty acids, hy substituting sulfuric acid for bctizenc.sulfonic acid. which shortens the rsterification time from 1 hour to 20 niinutc,c. ii packcd column is introduced bctn.cen the reaction flask and the condenwr for water scparation, in ordcr to inerrahe tlic (soncentration of benzcne in thc vapors. The esterification solution consists of 50 nil. of 1-butanol, 500 nil. of benzpnc, and 6 grams of concentrated sulfuric acid rcfluxed for 30 minutes to form butyl hydrogcn sulfatv. The allparat,us is illustrated a i d coniliarat i r e figures are givcn. Light colored acids are t i t r a k d to phenolphthalein and dark products are titrated poteiitionietrically. TKOcorrrctions arc' uscd VOL. 31, NO. 4, APRIL 1 9 5 9
675
in the calculation, one for the unesterified fatty acids and one for the rosin acids TT hich became esterified. Good agreement is indicated for the whole range of rosin acids and fatty acid composition. Chlorinated rubber and poly(vinj-1 chloride) are determined in the presence of each other by Sorwitz (52), who separated the two resins with chloroform, in n hich the chlorinated rubber is soluble. The chlorine content of each is then determined after fusion with sodium carbonate. Schweyer (61) has made an exploratory study of the spectral absorption of several asphaltic materials and considered the applicability of the Beer-lambert law to asphalts dissolved in a mixture of iso-octane and n-butyl alcohol for ultraviolet absorption, and in carbon tetrachloride and thin films for infrared absorption. Typical spectrograms are given.
SPECIFIC CONSTITUENTS
A rapid microscopical technique for identifying a single dicarboxylic acid in a n alkyd resin or polyester (16) involves examination of crystals of the free acids formed by systematic hydrolysis of the dipotassium salts obtained by saponification. The distinctive characteristics are illustrated by dram ings and photographs. Eleven dicarboxylic acids are included in the study. The method is limited to the detection of single acids or to combinations of similar solubility; isophthalic acid cannot be distinguished from terephthalic acid. The possibilities and limitations of detecting the three isomeric phthalic acids and benzoic acid in alkyd resins from the infrared absorption spectra of dried films were investigated (1). The information was considered useful for improving the speed and accuracy of subsequent quantitative analysis. Microcolorimetric methods for the qualitative and quantitative determination of o-phthalates and succinates in coating materials were supplied (69). The tests may be applied directly to dried coating materials or resin solutions by reaction with hydroquinone in the presence of sulfuric acid and extraction of the colored products with benzene. -4yellow color forms with phthalates and a red color a i t h succinates and these change on washing with alkali to violet and blue, respectively. The succinates cannot be determined in the presence of phthalates. This qualitative test is more reliable than any existing means of identifying phthalic anhydride in alkyd resins. Mixtures of adipic, sebacic, and phthalic acid were analytically examined by Clasper and Haslam ( I O ) . After
676 *
ANALYTICAL CHEMISTRY
saponification, adipic or sebacic n as separated from phthalic acid by the use of a silicic acid column buffered to p H 4.3 and the butanol-chloroform eluates nere titrated with standard alkali. Garn and Gilroy (24) report that the usual saponification of maleate esters with potassium hydroxide in alcohol form? the tetrapotassiuni salt Kith alcohol of crj stallization due to dimerization. They based their analysis on a two-phase saponification using benzene or chloroform and normal aqueous alkali. The samples were shaken for 3 hours, the water layer was separated and neutralized with sulfuric acid, and the maleic acid determincd polarographically. A procedure that may have application to thc analysis of coating materials was supplied by Kebbia and Guerrieri (51) which uses anthracene to measure maleic acid or anhydride in mixtures with similar compounds with a precision to 0.2% and without interference from fumaric, succinic, tartaric, phthalic, or tetrahydrophthalic acids. The reaction is conducted in chlorobenzene. The adduct of anthracene with maleic anhydride is insoluble in water and cannot be titrated after dilution, so that the maleic can be calculated by a reduction in the acidity of the mixture. A number of mono-, di-, and tricarboxylic acids, fatty acids having 10 to 16 carbon atoms, and natural oils are identified and approximately determined by their derivatives from ethanolamine (81). Primary use is made of melting points and solubilities. Included are such acids as adipic, maleic, fumaric, citric, and phosphoric acid and its esters. Terminal carboxylic groups of various polyesters prepared from such acids as maleic, fumaric, succinic, and adipic were determined (20) by potentiometric titration with a solution of sodium alcoholate. Glycerol has been separated from poly01 mixtures by paper chromatography and eluted from the indicated zone with water (65). It is then measured colorimetrically from the formaldehyde produced from periodic acid oxidation. Glycerol content ranging from 15 to 100% was determined with an average recovery of 101%. Kappelmeier and Mostert (SO) measure the pentaerythritol and tri(hydroxymethy1)ethane in alkyd resin vehicles by filtering off the crystallized polyols after aminolysis ith phenylethylamine. After isolation, each alcohol is determined by its hydroxyl number. Durbetaki (IS) proposes a n improvement in the titration of oxirane oxygen in epoxy resins and compounds using hydrogen bromide in glacial acetic acid. The advantages over other methods are stated to be a saving of time and operations, use of a visual end point, and extension of the range of applicability. Limitations are discussed and compara-
tive analyses presented. Stcnniark (61) applies the hydrochlorination reaction for determining the a-epoxide group to samples containing interfering materials, by measuring the disappearance of chloride ions rather than acid consumption. The method is applicable to $aniples containing amines and compares favorably in accuracy n-ith other epoxide procedures. Small concentrations of glycol groups in epoxy resins are determined (68) in chloroform x i t h an alcoholic solution of a quaternary ammonium periodate as reagent. Bring and Kadlecek (9) compared six analytical methods for the determination of hydrouyl groups in epoxy resins. Small amounts of unreacted isocyanate in polyurethan resins can be determined potentiometrically (50). T n entj five milliliters of 0.01 to 0.1-Vhydrochloric arid and a fen cr>stals of quinhydrone are added to the solution of the lacquer in 10 to 20 ml. of cyclohcxanone containing some diethvlamine and the solution is titrated mith 0.01 to 0.LY sodiuin hydroxide. The method is rapid and can be used to study polymerization in coatings. Kubitz (34) describes sensitive tests for traces of unreacted isocyanate groups in urethanbased polymers. For quantitative purposes, an excess of n-butylamine is added and the excess found colorimetrically n ith 3Ialachite green. Qualitatively, a colorless secondary amine der k e d from Malachite green is reacted to form a colored product. Lord ( $ 2 )has departed from the conventional amine method for deteiniining total isocyanate because it fails to distinguish between different isonierq. He utilizes infrared spectrophotometric procedures for analyzing mixtures of toluene-2,4-diisocyanate and toluene-2,G-diisocyanate. Two different procedures are supplied for mixtures in which the 2,4-isomer content is over or under 957,. Both methods are based on the quantitative measurement of bands a t 12.36 and 12.8 microns. Analytical results on mixtures containing varying ratios of isomers are presented and good accuracy is indicated. Other toluene-diisocj-anate isomers interfere; the extent of interference is discussed. Quantitative infrared analysis has been applied by Miller and Willis (44) to the measure of residual monomer in polj (methyl methacrj late) and the anal> sis of styrene-butadiene copolvmers. The latter is accomplished from the ratio of aromatic (2.2 microns) to aliphatic (2.4 microns) carbon-hydrogen groups. The methyl methacrylate is measured by using the shoulder of the saturated methylene band near 1.7 microns. In order to estimate the poly(ethy1 esters) in poly(methy1 methacrjlate) copal!. niers, Haslam and associates (26) convert the alkoxy1 groups to the corresponding iodides, which are then deter-
mined by gas-liquid chromatography. A feiT- samples of known coniposit’ion were tested with good accuracy. Hydroxymethyl groups in phenolformaldehyde resins are calculated from the water formed by condensat’ion with phenol in the presence of toluene-psulfonic acid (83). Karl Fischer reag m t is used. Free phenol and aniline iii aniline-phenol-formaldehyde resins arcs tlctermined (64) in the steam distill:itv by nritling excess hydrochloric acid iv1iic.h mnverts the aniline to the etheri ~ i s ~ i l u lhydrochloride. ~lr The phenol is estractcd with ether and both compoiwnts estimated by knon-n methods. A ltmiativcly, t’he tu-o components are wparated by steam distillation first in :in :ilk:iline and then in an acid environlli?llt. Infrared spectrometry has been app l i d (??) to the determination of iiiono- and dimethylolurea with a stand:ml deviation of about 1.i%! using key bands at 9.8i and 9.53 niirrons, respectivvly. Samples were prepared by the potnssium bromide pellet technique. JIethylated niethylol groups in melamine-formaldehyde resin solutions are qiiantitatively analyzed ( 7 s ) by hydrolysis with dilute sulfuric acid followd by :in iotloiiietric technique,. llethanol i n u 4 first be removed if pwsent. lIitrhell, Hockman, aiid Lee (46) have cicxvcloped method for the determination of the acetyl content of cellulose acetate by near infrtired spectroscaopy. 1-nreneted hydroxyl absorbance a t 144*5nip is utilized. =I comparative study n‘as made of the accuracy. Fish1 and Young (21) compared relative aniounts of phrnyl and alkyl radicals in cliffereat silicone resins by observing the absorljance ratios near 3.3 micron.. Samples werr prepared by sprcadiiig the resins on flat salt plates, air drying, and repeating this procedure until tIiP hands of int,ercst showed absorptioii? of suitable intensity. Hydrolysis products from silicone resins and other complrx silanols were analyzed by Gucmt1ic.r (26) using niethylniagnesium iodide in dibutyl ether under an atmosplic,re of niethanc.. I3athcr ( 6 ) has supplied a procedure for thc niicrocleterinination of chlorine in small samples of polymerized and copolyniwized vinyl rhloride. A special niicroapparatus is described for analyzing 1.5 ing. of sample. Thc so-called “brittle resins” were iiieasurrd (12) in paint vehicles by carefully saponifying samples lyith 0 . 5 S alcoholic potassium hydroxide, so that only oilh and alkyds are affected. The resins are then calculated as the sum of unsaponifiahle and nonesterified resin acids. OILS A N D FATTY ACIDS
Saturated acids in mixed fatty acids
are estimated by Spickett and associates (66) by oxidizing the methyl esters of the mixed fatty acids in petroleum solvent, passing through a n alumina column, evaporating the solvent, and weighing the saturated methyl esters. Kuemmel (36) also determines saturated acids directly on fats and oils with a procc,dure involving methanolysis of triglycerides, oxidation of unsaturated methyl esters with permanganate, removal of the undesired acidic oxidation products by alkaline washing, followed by isolation aiid weighing of the saturated methyl esters. The method is claimed to be suitable for fatty acids having chainq of 16 or more carbons, if large amounts of loner saturated acids are absent. Fries and associates (23) detect unsaturated fatty acids by treatment of a chromatogram with ozone, followd by spraying with fuchsin in sulfurous acid nhich makes the individual unsaturated acids visible. Reversed phase paper chromatographic analysk \vas applied (38) to the identification of fatty acids obtained in the analysis of lacquer$. The paper was treated v i t h undecane saturated with glacial acetic acid, then developed with glacial acetic acid saturated with undecm e . The fatty acids then reacted n i t h cupric acetate and the copper salts were detected n i t h potassium fcrrocyanidc. resulting in patterns of various saturated and unsaturated fatty acids. This n-ork TI as practically duplicated in another application (31) of paper chromatography to the separation of mixcd fatty acids. Both papers include a thorough discussion of the method. I n the latter, horizontal development was preferred, and the acids studied varied from 14 to 20 carbons. Lipsky and Landowne (41) describe (in English) their investigations into the use of different types of partition agents for obtaining quicker, sharper, and more complete resolution of the 18-carbon unsaturated fatty acids by gas-liquid chromatography. They indicate preference for the adipate polyester of diethylene glycol to the use of hydrocarbons. Their work was conducted with the methyl esters of the acids. Montequi and associates (47) claini a constant relationship hetween the viscosity and acetone number of individual drying oils that can serve as a means of identification. Oiticica oil in coating materials can bc detected (14) by the red color developed n-ith m-dinitrobenzene. The carbonyl group of the principal fatty acid constituent is responsible for its use as a specific test. ASSOCIATED MATERIALS
Lucchesi and Hirn (43) have presented a useful, comprehensive procedure for determining the nietal content of paint driers by a titrimetric
method that does not require decomposition. The drier is dissolved in alcohol-benzene solution and the metals are chelated with excess EDTA, which is back-titrated with zinc chloride to the Eriochrome Black T end point. The inethod is simple and rapid and almost as accurate as other slower methods. A technique has been described (86) for measuring small amounts of lead in paints, a t the 1% level, by n-et-ashing TI ith persulfuric acid and precipitating as lead chromate. Verma and Bhuchar (84) describe the rapid estimation of lithopone through the complexinietric estimation of zinc and barium in admixture. The titration is conducted againqt a qtandard solution of EDTA a t p H 6 . i and 10, respectively. The method is rapid and the analytical data preqented indicate good accuracy. The polarographic analysis of chromate pigments mas reported (6),permitting determination of the heavy metals and the chromate in lead or zinc rhromate pigments in a single operation. The test procedure and the preparation of solutions are exactly described and a number of practical tests are given. Spurr and PIIyers (66) used x-ray diffractometry to measure relative amounts of anatase and rutile in titanium dioxide. Lamprecht (36) recommends the same basic method, adds that other physical measurements are not reliable, and proposes in addition, a simple iodometric method based on the difference in photochemical activity of anatase and I utile titanium dioxide. Keuhn (32) has described two n m l y developed methods for measuring aromatics in hydrocarbon solvents. One is based on the reaction of aromatic hydrocarbons n ith chlorosulfoiiic acid to form sulfonic acid chlorides and \rater. The n ater reacts with excess chlorosulfonic acid evolving h! drochloric acid n hich is absorbed in water and titrated. It is claimed that the second method can be used to ascertain both the aromatic and olefinic content of hydrocarbon solvents. I n this method, the sample is heated with concentrated sulfuric acid and poured into nater. The free sulfuric acid is detcrmincd on an aliquot as barium sulfate and the rcst, R hich is not accounted for. is considered present as sulfonic acid. To determine the olefinic portion, an aliquot is saponified and calculated from the difference of the sulfate precipitations. S o analytical data were presented. The cause of poor accuracy in the dctermination of ketones in lacquer solvents and thinners by the hydroxylamine hydrochloride method was investigated (16). The method was modified to overcome two sources of error with resulting improvement in accuracy. An additional technique was described for applying the method directly to lacquer vehicles without prior solvent isolation, VOL. 31, NO. 4, APRIL 1959
677
thus providing a rapid method for this purpose. Salicylanilide in fungus-resistant varnishes has been measured (13) n-ith high accuracy by the absorption of alkaline extracts in the ultraviolet region. Several nirthods have appeared for the detection of shellac in varnishes and lacquers in mixtures with other resins and nitrocellulose. Vollmann (85) describes several methods and considers the hest tcsts t’o -be based on the presence of a dye that forms a yiolet salt with alkali. but adds that the most, exact detection niethod is the isolation of nleuritic acid. Proccdures are outlined for isolating shellac and the acid from mixtures. -1specific met’liod that can be applied directly t’o varnishes and lacquers wit’liout separation of the shellac has also been described (?), in m-hich n rose caolor fornis when the material to be testcd is mixed into a paste with zinc oxide. The test is stated to be negative with all other natural or synthetic resins. A gravimetric method for determining quaternary ainnionium compounds (used in water emulsion paints) n-as developed hy Lincoln and Chinnick (39). Thc compounds are precipitated from a dilute hydrochloric acid solution with phosphotungstic acid. By neighing the precipitate after it has been dried a t 150” C. and again after ignition, the amount of quaternary ammonium compound and its molecular weight can be calculated. .lmnionia and amines interfere and suggest’ions for overcoming interference are discussed. Tables include the analysis of 11 compounds and some of their calculated molecular weights. Kronstein and associat’es (35) have supplied methods for stripping phosphate coat’ingsfrom steel and analyzing them both qualitatively and quantitatively. mostly by spectrographic methods. The coatings analyzed were found t’o contain the metals present in original phosphating solutions. Lasko ( 3 7 ) employs a niultiple replicating system for examining paint surfaces in electron microscopy. The system gives good reproduction and does not attack the surface. Aqueous iiirthylc~ellulose is used for the primary replira, follon-ed by carbon evaporation and shatlon-ing v-itli chromium.
( 7 ) Beneneon, AI. V., Gorlovakii, S. I., Slutskaya, F. .I.,Dereuoobmbatyuayushchaya P r o m . 4, 17 (1955). ( 8 ) Biasotto Mano, E., Cunha Lima, L. C. O., Reo. guim. ind. 25, 17-19 (1956). (9) 7Bring, d., Kadlecek, F., Plaste t i . haUtschuk 5, 43-8 (1958). (10) Clasper, AI., Haslam, J., J . d p p l . Chem. ( L o n d o n ) 7, 328 (1957). (11) Dooper, R., van der Valk, J. A. AI., T’erfkroniek 29, 171-2 (1956).
(12) Ibid., 30, 10-11 (1957). (13) Durhetaki, LI.J., .Is.IL. CHEJI.28, 2000-1 11956). (14) Esposito, G. G., Sn-ann, 11. II., Zbid., 29, 1861 (1957). (15) Ibtd., 30, 1643 (1958). (16) Esposito, G. G., Swann. AI. H.. O f i c . -Dig. Federation P a i n t ck T’arnish Production Clubs 30, 1059-69 (1958). (17) Fanica, L., C h i m anal. 38, 353-61
(1956). (18) Feigl, F., “Spot Teste in Organic Analysis,” 5th ed., p. 485, Elsevier, Princeton, 1956. (19) -Ibid.. n. 486. ~. (20) Fijolk’a, P., Lenz, I., Runge, F., JIakromol. C h e w . 23, 60-70 (1957). (21) Fishl, IT., Toung, I. G., -4ppl. Snectroscom 10. 213-15 11956). (22j ~raser,‘i.G.; Pross, A: K., Ofic. Dig. Federation P a i n t &2 V a r n i s h Production Clubs 29, 75-81 (1957). (23) Fries, J., Holasek, AI, Lieb, H., JIikrochinz. S e t a 11, 1722-6 (1956). (24) Garn, P. D., Gilroy, H. AI., .ISAL. C H E ~ I30, . 1663-5 (1958). (25) Guenther, F. O.,Zbid., 30,1118(1958). (26) Haslam, J., Hamilton, J. B., Jeffs, A. R., A n a l y s t 83, 66-71 (1958). 127) Haslam. J.. Sauirrell. D . C. AI., ‘ Zbzd., 82, 511-17 (f957). (28) Hummel, Dieter, “.%nal>-sisof Synthetic lIaterials. Lacquers, and Rubber,” 5’01s. I and 11. Carl Hanser 5’erlac. AIunich. 1958 (29) Htmmel, Dieter, Kunststo$e 46, 442-50 (1956). (30) Kappelmeier, C. P. h., Nostert, J., Verjkroniek 30, 48 (1957). 1311 Kaufmann. H. P.. Alohr. E.. Fette. &ifen, ilust,.ichmittel’60, 165-77 (1958); (32) Keuhn, AI.>P a i n t I’arnish Production 4 6 , 105-6 (1956). ( 3 3 ) Kronstein, AI., Kass, S., Van Dien, J. E.. Zbid.. 47. 46-50 11957). (31) Kuhitz,’ K. -I.,. l s a ~‘CHEII. . 29, 814 (1957). (35) Kiienimel, D. F.,J . Am. Oil. Chemists’ SOC.35, 41-5 (1958). 136) Lamorecht. IT,, Farbe z i . Lack 63, ‘ 3i2-5 ( i w ) . (37) Lasko, \I7,R., .%SAL. CHEX 29, 784 (1957). (38) Lichthardt, U., Farbe u . Lack 6 3 , \ - - ,
\ -
I
,
387-93 (1957).
(39) Lincoln, P. A , , Chinnick, C. C. T., ;2nal?jsi 81, 100-1 (1956). (10) Linder, A , , Persson, 5’.j J . A u f . Oil Cheiifists’ Soc. 34, 24-7 (1957). (41) Iipsky, S. R., Landowne, R. -1.) Biochiin. el Biophgs. Acta 27, 666-7 (1958).
(42) I,Ord, 8.S.,- 4 S . I L . CHEJI. 29, 497-9 (1957). LITERATURE CITED 143) Lucchesi. C. .I..Hirn, C. F., I b i d . , ( 1 ) hdams, AI. I,., Sir-ann, 11. H., -1s.i~. 30, 1877 (1958). CHEX 30, 1322 (1958). (44) Aliller, R . G. J., Killis, H . .1.,J . ( 2 ) -Idanis, AI. L., Sn-ann, AI. H., Ofic. -4ppl. Cheni. ( L o n d o n ) 6 , 385-91 (1956). Dig. Fedemtion P a i n t & V a r n i s h Pro(45) AIitcht,ll. J., “Organic -Inal?-sis,”5’01. 111. IIII. 1X-508. Intrrxirnce. Seir To;k: i956. (46) lIitchel1, J. .I.,Bocliman, C. D., Lee, -4.V,,SAL. C I I E U . 29, 499-502
(1957). (47) AIontecliii, R., Doadrio, A., Morales, J. L.. Gmsas y aceites ( S e d l e , S p a i n ) 8, 11-13 (1957). 678
ANALYTICAL CHEMISTRY
(48) Alorath, J . C., Il-oods, J. T.,
;\AAL.
CHEX 30, 1437 (1958). (49) AIinyhl-j J. E., Schn-enier, K. C., Ibzd., 30, 116 (1958). (50) Savyazhsltaya. F. .I..Khzm. Proin. 432-3 11956).
(51) Sebkiia, L., Guerrieri, F., Chi,,i. e i n d . ( M i l a n ) 39, 17-18 (19571, (.52) Sorrvitz, George, Ofic. D i g . Federation P a i n t B I’arnish Pi.oducfion Clubs 30, 1049 (1958). ( 5 3 ) O’Seill, L. A,! Cole, C. P., J . d p p l . Chem. (London) 6 , 399-407 (1956j. (54) P a i n t JIanzLf. 27, 150 (1957j. ( 5 5 ) Ibid., 28, 122 (1958). (56) P a i n t V a r n i s h Pi,odicction, S o . 3, 73 (1958). ( 5 7 ) Reichherzer, R., X i i t . chejji. Forsch. Inst. TVirtsch. Ost. 11, 141-6 (1957). (58) Samsel, E. P., ;\ldrich, J. C., .%SAL. CHEJI.29, 574-6 (1957). (59) Schneebeli, P., Lalau-Ikaly, F., Recherche akronauf. ( P a i i . s i , S o . 56, 41-6 (1957). (60) Schurz, J., Bayzer, H.. Stuhchen, H., Illakronio2. C h e m . 23, 141-51 (1957). (61) Schrveyer, H. E., -1s.i~. CHEX. 30, 205 11958).
(62) Seidl, J., 1-asta, AI., Che,,i. listij 50, 2031-4 (1956). (63) Sniullin, C. F., Hartmrtnn, L., Stetzler. R. S..J . d i n . Od Chemzsfs‘ Soc. 35, 176-82 11958l.
(66) Spurr, R. .I.,Myers> H., -1s.i~. CHEJI.29. 760 11957). ( 6 7 ) Strnmark, G. .I.,’ Zbid., 29, 1367-9
(1959).
( 6 8 ) Zbid., 30, 381 (1958). (69) Sivann, AI. H., Ibid., 29, 13.52 (1957). (70) Zbid., p. 1604. (71) Ibid., p. 1505. ( 7 2 ) Sir-ann, AI. H., Ofic. Dig. Federation P a i n t &: T’arnish Production Clubs 30, 1277 (1958). ( 7 3 ) Srann. hf. H.. .Idama.’ AI. L.. h s a ~ . ‘ CHEJI. 30; 1807 (1958). (74) Sn-ann, AI, H., Esposito, G. G.: Ibid., 29, 1361 (1957). ( 7 5 ) Zbid., 30, 107 (1958). (76) Szymanski, H. h., Conley. R. T., Zhid., 30, 552 (1958). ( 7 7 ) Tanaka, S.,Ogan-a, AI., AIiyamoto Y., Yoshimi, S . , B u n s e k i Kagakic 6 , 562-4 (1957). ( 7 8 ) Tanimoto, II., Ulbrich, T ., Chojt. lisfu 4, 1311-14 (1955). (84) TTerma, 11. R., Bhuchar, I-. AI., Paint I l a n i i f . 27, 384 (1957). (8.53 17011manii~ H., J . Oil & Coloicr Chemi.sts’ . h o c . 40, 175-82 (1957). (86) Kestgate, hl. IT., Sllurts. R . B., Adanis, E. F., Xatl. Paint, \‘arnish, T,accliier .%seoc. Circ. 773, S-17 (1956’). ( 8 7 ) Kiherley, S. E., Spragiie, J. IT., Campbell, J. E., _\SAL. C H E M29, 210l:? (1957). (88) Kidnier, G., Krtnsfsto,fTe 4 6 , 3!5!3-62 il0.ifi)’ ,L~’’’-
(89) Zalirodkiii, A . G., Dercmohrabatymgitshchaya Prom. 5, 8-10 (1956). (90) Zanibrini, -4.>I., Pitture e ccrnici 13,
al-4 (l9(57).
