Gene Sumrell

Direct sampling capillary gas chromatography of volatiles in vegetable oils

Direct sampling gas chromatography used for determining volatiles and, indirectly, the flavor of vegetable oils, has been improved by a capillary column in place of the usual packed columns. Data on two good vegetable oils from a supermarket, and on one of these samples after intentional deterioration, are presented. Use of the capillary column provides a more efficient technique to differentiate between the better oils than did the previously used packed columns.

Isolation of methylcis, cis-5, 13-docosadienoate fromLimnanthes douglasii oil

Methylcis,cis-5,13-docosadienoate has been isolated from the mixed methyl esters of the fatty acid moiety ofLimnanthes douglasii oil by a combination of low temperature fractional crystallization and fractionation of mercuric acetate adducts. The methyl ester and its free acid have been characterized.

Fatty acid polymorph identification by infrared

IR spectra in the 7.5–25.0 µm region are shown to be unique for polymorphic modifications of long chain saturated fatty acids of even carbon number and also for the individual fatty acids. IR spectra are presented for the A-, B-, C- and E-forms of stearic acid and for the C-form of myristic, palmitic, arachidic and behenic acid and the differences discussed. X-ray determined crystal long spacings for the A-, B-, C- and E-forms of a series of homologous even carbon-numbered acids are presented and compared with literature values. The formation of the different polymorphic forms are found to be temperature-concentration related and affected little by polarity of the solvent. Wideline nuclear magnetic resonance second moment values are given for the polymorphic forms of stearic acid.

Analysis for trace amounts of geosmin in water and fish

Trace amounts of geosmin (trans-1,10-dimethyl-trans-9-decalol) were concentrated from relatively large volumes of water by vegetable oil extraction. After stirring the two phases for 30 min, the dispersed oil was allowed to separate. The oily layer was removed and centrifuged to break the emulsion and separate the two layers. The direct gas chromatographic technique was used to resolve the geosmin from other volatile components on a capillary gas chromatographic column. Volatiles were separated from the oil by securing an aliquot of the oil layer on volatile-free glass wool in the glass liner of the special gas chromatography inlet system. Geosmin was detected at the parts ber billion level with this simple and rapid technique. A technique also was developed for detecting geosmin in fish tissue; it involves steaming the fish to break up the tissue, centrifuging the residual oil phase, and detecting geosmin by capillary gas chromatography. The geosmin remains in the residual oil.

Some derivatives of 5-eicosenoic acid

Abstractcis-5-Eicosenoic acid and its methyl ester have been epoxidized. Preparation of an hydroxylactone through lactonizaton of both the 5,6-epoxy acid and the 5,6-dihydroxy acid has been investigated. 5-Eicosenoic acid has also been converted to γ-lactone through use of perchloric orp-toluenesulfonic acid. The preparation of several other related new compounds is described.

Lubricants and lubricant additives: II. Performance characteristics of some substituted fatty acid esters

Sixty-one compounds, principally substituted fatty esters of mono- and polyhydric alcohols, but including some amides and two imidazolidines, were prepared and evaluated as lubricants and lubricant additives for paraffin and diester base oils. The effects of chloro, phosphato, phosphorodithio, thio, epithio, mercapto, and sulfuryl substituents, alone and in certain combinations, on the performances of the compounds as antiwear and extreme pressure lubricants were investigated. The epithio (thiirane) group was the most effective and consistent in enhancing extreme pressure and antiwear performances of the compounds as additives. Sulfurized and chloro-sulfone derivatives also were effective, but perhaps somewhat less predictably so, than the epithio derivatives. The phosphato and phosphorodithio derivatives were good, consistent, antiwear additives, but only the latter seemed potentially useful for improving extreme pressure lubrication. Structure-performance correlations favor use of the esters over the amides.

Analysis of trace volatiles in food and beverage products involving removal at a mild temperature under vacuum

Abstract A simple approach for the detection and identification of volatiles in food and beverage products involving removal at mild temperatures under vacuum is presented. Volatiles are stripped from the sample between 30 and 60°C and adsorbed onto a Tenax-GC trap at 8 psi. The GC oven is cooled to −30°C for several minutes. Then the moisture-free volatiles are desorbed directly onto the cold capillary GC column and resolution is accomplished by temperature programming. This approach minimizes thermal decomposition and permits the detection and identification of trace volatiles in foods and beverages down to the parts-per-billion level by GC-MS.

Lubricants and lubricant additives: I. Performance characteristics of N-mono and N,N-Disubstituted fatty amides and modified fatty amides

A number of N-mono and N,N-disubstituted amides of substituted and unsubstituted C18 fatty acids have been prepared and evaluated as base lubricants and lubricant additives. The neat epithioamides possess extreme pressure lubricant characteristics and are noncorrosive at normal temperatures. The epithioamides also frequently function as extreme pressure additives and antiwear agents for paraffinic or diester base oils, sometimes in both capacities for both base oils. The intensiveness of these properties correlated directly with the degree of thiirane substitution in the compound. Performance in both these capacities at the same levels of epithioation was dependent upon the N- or N,N-substituent groups present.

Antimicrobial activity of some fatty acid derivatives

Petroselinic and ricinoleic acids and a number of their derivatives, together with stearic acid and two oleic acid derivatives which were in-cluded for the purpose of comparison, have been screened for antimycotic activity against 22 pathogenic yeasts and molds. A number of the compounds exhibited a wide spectrum of activity, testing either fair or good against all or most of the yeasts and molds, and almost all were fairly active against at least one of the organisms.

1,3-Diacyl derivatives of imidazolidine and hexahydropyrimidine: I. Preparation by novel method and characterization

The reaction of formaldehyde and diamides of 1,2-diamines in acetic acid containing a trace of hydrochloric acid was found to give 1,3-diacyl derivatives of imidazolidine in high yield. The similar reaction of formaldehyde and diamides of 1,3-propylenediamine gave high yields of 1,3-diacylhexahydropyrimidines. Attempts to extend this reaction to other aldehydes than formaldehyde failed, as did attempts to condense formaldehyde with a diamide which would give a four-membered or seven-membered ring system, the diamide being recovered unchanged in each instance. Twenty-two new compounds were prepared and characterized.