Identification of Surface Active Agents As Trimethyl Silyl Ether Derivatives by Gas Chromatography

Robert Suffis; Thomas J. Sullivan; William S. Henderson

J. Soc. Cosmetic Chemists, 16, 783-794 (1965) Identification of Surface Active Agents As Trimethyl Silyl Ether Derivatives by Gas Chromatography ROBERT SUFFIS, M.A., THOMAS J. SULLIVAN, B.S., and WILLIAM S. HENDERSON, B.S.* Presented May •, 1965, New York City Synopsis--A method is presented for the analysis of some non-ionic surface active agents by gas chromatography. The components of these agents are converted to their volatile tri- methyl silyl ether derivatives prior to analysis by reaction with hexamethyldisilazane and trimethylchlorosilane. The volatile derivatives of the surface active agents may then be easily separated by gas chromatography. This procedure has been found to be applicable to a variety of glycol esters and sorbitan esters which are frequently utilized in cosmetic and toiletries formulations. In addition, the method could be utilized to provide information concerning the chemical properties of a surface-active agent. Rapid analysis for mono-ester and di-ester concentrations, free glycol, and fatty acid composition is possible through use of this technique. INTRODUCTION The analysis of partial esters of polyhydric alcohols and other non-ionic surface active agents has been performed by chromatographic techniques. These methods have utilized silica gel columns and various solvent systems to effect these separations (1-3). In addition, there is considerable literature on the analysis of glycerides by paper (4, 5) and thin-layer chromatography (6-8). Research on these separations has also been performed utilizing countercurrent distribution (9) and liquid- liquid extraction (10). Most of the work in this field has been per- * The Mennen Company, Morristown, N.J. 783

784 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS io RETENTION TIME (Minuies) io 15 20 RETENTION TIME (Minutes} Figure 1. Top: Glyceryl monostearate in pyridine Bottom: Glyceryl monostearate after trimethylsilylation formed by lipid chemists. Therefore, most of the data cover fatty glyc- erides only. However, the same approaches should be possible for any glycol ester. The above references describe techniques for the separation of the mono-ester, di-ester, and tri-ester components of the glycerides. These methods, applied to the identification of surface active a•ents, are lengthy, tedious, and usually not sufficiently specific for unequivocal identification. There has been some research into the use of gas chromatography for the analysis of glycol esters. Triglycerides have been analyzed directly by high-temperature gas chromatography (11). However, the mono and diglycerides cannot be analyzed without conversion to a non-polar

Previous Page Next Page

Purchased for the exclusive use of nofirst nolast (unknown)
From: SCC Media Library & Resource Center (library.scconline.org)

Volume 16 No 13 resources

Download PDF Identification of Surface Active Agents As Trimethyl Silyl Ether Derivatives by Gas Chromatography (12)

Extracted Text (may have errors)

J. Soc. Cosmetic Chemists, 16, 783-794 (1965) Identification of Surface Active Agents As Trimethyl Silyl Ether Derivatives by Gas Chromatography ROBERT SUFFIS, M.A., THOMAS J. SULLIVAN, B.S., and WILLIAM S. HENDERSON, B.S.* Presented May •, 1965, New York City Synopsis--A method is presented for the analysis of some non-ionic surface active agents by gas chromatography. The components of these agents are converted to their volatile tri- methyl silyl ether derivatives prior to analysis by reaction with hexamethyldisilazane and trimethylchlorosilane. The volatile derivatives of the surface active agents may then be easily separated by gas chromatography. This procedure has been found to be applicable to a variety of glycol esters and sorbitan esters which are frequently utilized in cosmetic and toiletries formulations. In addition, the method could be utilized to provide information concerning the chemical properties of a surface-active agent. Rapid analysis for mono-ester and di-ester concentrations, free glycol, and fatty acid composition is possible through use of this technique. INTRODUCTION The analysis of partial esters of polyhydric alcohols and other non-ionic surface active agents has been performed by chromatographic techniques. These methods have utilized silica gel columns and various solvent systems to effect these separations (1-3). In addition, there is considerable literature on the analysis of glycerides by paper (4, 5) and thin-layer chromatography (6-8). Research on these separations has also been performed utilizing countercurrent distribution (9) and liquid- liquid extraction (10). Most of the work in this field has been per- * The Mennen Company, Morristown, N.J. 783

784 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS io RETENTION TIME (Minuies) io 15 20 RETENTION TIME (Minutes} Figure 1. Top: Glyceryl monostearate in pyridine Bottom: Glyceryl monostearate after trimethylsilylation formed by lipid chemists. Therefore, most of the data cover fatty glyc- erides only. However, the same approaches should be possible for any glycol ester. The above references describe techniques for the separation of the mono-ester, di-ester, and tri-ester components of the glycerides. These methods, applied to the identification of surface active a•ents, are lengthy, tedious, and usually not sufficiently specific for unequivocal identification. There has been some research into the use of gas chromatography for the analysis of glycol esters. Triglycerides have been analyzed directly by high-temperature gas chromatography (11). However, the mono and diglycerides cannot be analyzed without conversion to a non-polar

Help

REACTION OF a-HYDROXYMETHYL KETONES 781 analyzed for bromine. The amount of bromine in these samples was too low to be detected. 5. Bovine albumin is a water-soluble, ethanol-insoluble protein. Treatment of bovine albumin with absolute ethanol, if the times are not unduly prolonged, does not alter its water solubility. However, it was observed that, when a suspension of bovine albumin, absolute ethanol and either DHA, phenacyl alcohol, p-bromophenacyl alcohol, or p-nitro- phenacyl alcohol was shaken overnight, the bovine albumin became slightly colored and was converted into a water-insoluble form. When p-dimethylaminophenacyl alcohol was used, the bovine albumin was not converted into a water-insoluble form, and no color change in the al- bumin was noted. DISCUSSION The reaction of callus and amino acids with a-hydroxymethyl ketones to produce colored products appears to be a general one, and the rate of reaction appears to be related to the concentration of reagents. In addition, there is a suggestion that the reaction is enhanced (as judged by the intensity of the colors produced) if electron withdrawing groups are attached to the a-hydroxymethyl ketone. Thus, the order of de- creasing color intensity of treated callus was p-nitrophenacyl alcohol, p-bromophenacyl alcohol, phenacyl alcohol and p-hydroxyphenacyl alcohol. In addition, it was noted that of the a-hydroxymethyl ketones reacted with bovine albumin only p-dimethyl amino phenacyl alcohol was without effect on its color and solubility. If the color formations were related to a Maillard type of reaction (8) (as suggested by the fact that removal of amino groups with formaldehyde blocked the reaction), such an activating effect would be predicted for electronegative groups. Comparisons of the effects of amino acid structure on the rate of reaction are indicated in Table II. Thus, increasing the chain length by one carbon atom (glycine vs. alpha-alanine, aspartic acid vs. glutamic acid) has little effect on the rate. On the other hand, comparison of a- vs. •-alanine shows the latter to be substantially more reactive. Thus, compounds with more basic nitrogen groups appear to produce a color reaction much sooner. This is also seen in the case of arginine, which is a relatively rapid reactor, and in the cases of the dicarboxylic acids, which are relatively slow reactors. The failure of the various analytical schemes to detect the presence of the reacted a-hydroxymethyl ketones on callus suggests that, although

782 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS in some cases relatively intense color was produced, very little material had actually reacted with the callus. It was observed, however, that in all cases where colored products were formed it was impossible to remove the color from the keratin by simple washing procedures. (Received July 16, 1965) (t) (2) (a) (4) (a) (6) (7) (8) (9) (lO) (11) REFERENCES Goldman, L., et al., .1. Invest. Dermatol., 35, 161 (1960). Wittgenstein, E., and Berry, H., Ibid., 36,283 (1961). Idem, Science, 132,894 (1960). Flesch, P., and Esoda, E. C. J., Proc. Sci. Sect. Toilet Goods Assoc., 34, 53 (1960). Maibach, H. I., and Kligman, A.M., A .M.A. Arch. Dermatol., 82,505 (1960). Lento, H. G., et al., Food Research, 25,750 (1960). Idem, Food Research, 25,757 (1960). Ellis, G. P., Adv. Carbohydrate Chem., 14, 63 (1959). Richards, E. L., Biochem. J., 64,639 (1956). McWeeny, D. J., and Bruton, H. S., Nature, 196, 40 (1962). Burton, H. S., et al., Ibid., 196,948 (1962).

Previous Page Next Page

Purchased for the exclusive use of nofirst nolast (unknown)
From: SCC Media Library & Resource Center (library.scconline.org)

Volume 16 No 13 resources

Download PDF The Reaction of α-Hydroxymethyl Ketones with Skin and Amino Acids (6)

IDENTIFICATION OF SURFACE ACTIVE AGENTS 785 derivative. The high boiling point and high polarity caused by the presence of one or more hydroxyl groups make it impossible to get good results by gas chromatography on the parent substance. Monoglycerides have been analyzed after conversion to allyl esters by a dehydration reaction (12). This method is applicable to glyceryl mono-esters only. Other work has been performed after converting the free hydroxyl groups 5 )0 RETENTION TIME (Mmufe• 2O Figure 2. Top: Diethylene glycol monostearate in pyridine Bottom: Diethylene glycol monostearate after trimethylsilylation to acetates by reaction with acetyl chloride (13). These techniques have given some interesting results, but each one has some serious drawbacks. The conversion to allyl derivatives is very lengthy and applicable only to components with two adjacent hydroxyl groups. The acetate deriva- tive preparation is also a lengthy procedure and gives rise to high boiling products. The research described in this paper has made use of the reaction of hydroxyl groups contained in surface active agents with hexamethyl-

786 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS disilazane and trimethylchlorosilane. The products are volatile tri- methyl silyl ether derivatives which are suitable for gas chromatography. The use of this reaction has received considerable attention in the sugar and carbohydrate field (14, 15). Compounds as high boiling as tetrasac- charides have been analyzed successfully. The reaction is simple and quantitative without any undesirable side reactions. These derivatives are lower boiling than the corresponding acetates and give sharp, well defined peaks on the gas chromatograph. The use RETENTION TIME (M•nutes) c • Figure 3. Top: Ethylene glycol monostearate in pyridine Bottom: Ethylene glycol monostearate after trimethylsilylation of this technique enables one to get a definitive chromatogram for each of the surface active agents investigated. A comparison of the chromato- gram obtained from the initial pyridine solution with that of the reacted

Previous Page Next Page

Purchased for the exclusive use of nofirst nolast (unknown)
From: SCC Media Library & Resource Center (library.scconline.org)

Volume 16 No 13 resources

Download PDF Identification of Surface Active Agents As Trimethyl Silyl Ether Derivatives by Gas Chromatography (12)

Volume 16 No 13 resources

All section downloads (PDF) click to expand contents

Extracted Text (may have errors)

Help

loading

Volume 16 No 13 resources

Volume 16 No 13 resources