FATTY ALKANOLAM I DES 117 Sample No. 6 is a 2:1 amide which was more than two years old. The material was liquid and it had a precipitate which was suspected to be N,N-bis(2-hydroxyethyl)piperazine. When subjected to the ana- lytical technique, the piperazine was found and it is eluted near the end o[ the chromatographic analysis. Figure 8 shows the histogram and the piperazine is in Fraction 55. The amido-amine which was detected in both 1:2 and superamides in shown in Fig. 9. Mg •3000 140( •2o, :T• ß•x•:,x •-:-• -:• 1000 .:.i_ ::_ '.'__ __ •,.!..'.. I:'' DEA AMIDE+ESTER :" : ' I I ' I" DEA AMIDE : "" II o• mPE•AZ•NE 0 I0 20 50 40 50 60 70 80 FRACTION Figure 8. Kritchevsky amide, 2:] ratio alter aging ESTER 100o0 lOO , I •80 •40 r • j •20 t 5000 4000 3000 2500 FREQUENCY (CM') 2000 1800 1600 1400 1200 1000 9,50 900 850 800 7,.50 700 6,0 5 6 7 8 9 10 11 12 WAVE[Er•OTH (*XtCROrqSl Figure 9. Infrared spectrum of amido-amine 13 14 15

118 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS SUMMARY Column chromatography in conjunction with int•rared spectroscopy can be used to elucidate the composition o[ both the superamide (1:1) and the Kritchevsky type (2:1) amides. The method not only sub- stantiates the presence o[ the various secondary products, but yields quantitative in[ormation and also reveals the presence o[ monoethanol- amide and the ester o[ monoethanolamide. This shows that commercial diethanolamine contains monoethanolamine as an impurity. The method can be used to study the effect ot: aging on the composition inso[ar as to the rearrangement o[ some o[ the components and the appearance o[ N,N-bis (2-hydroxyethyl) piperazine. The method also indicates the presence ot: impurities which were not part o[ the raw materials but were due to the solubility effect o[ the amides on such things as plastic bottles and caps with plastic liners. None ot: the 1:1 samples that were analyzed revealed any methyl esters but in subsequent work not covered by this paper small amounts ot: methyl ester were found to be present in several 1:1 amides. Thermal rearrangement o[ components was ascertained, whereby a diethanolamide was converted to a monoester diethanolamide and the subsequent conversion ot: the monoester diethanolamide to a diester amine. The soap component in the 1:1 amides is not eluted [rom the column as such. The method will indicate the presence o[ [ree [arty acid in the 1:1 amides which usually is not determined by the standard method o[ titration. ACKNOWLEDGMENT The authors wish to acknowledge Dr. Hyman Henkin and Mr. Paul Silverman [or their time and interest pertaining to this work. (Received May 21, 1969) REFERENCES (1) Kroll, H., and Lennon, W. J., The chemistry, analysis and applications of lauric acid- diethanolamine condensation products, Proc. Sci. Sect. Toilet Goods Assoc., 25, 37-41 (May, 1956). (2) Livengood, S. M., and Johnson, C. A., Analysis of high amide fatty alkanolamides, Chem. Specialties Mits. Assoc., Proc., 123-5 (Dec., 1957). (3) Rosen, M. J., A general method for the chromatographic separation o[ nonionic sur- face-active agents and related materials, Anal. Chem., $5, 2074-7 (1963).