Carbonyls in Oxidizing Fat. VI. The Girard T Reagent in the Isolation and Determination of Micro Amounts of N‐Aliphatic Aldehydes and 2‐Alkanones

Abstract

Complete reaction of the Girard T reagent with n-alkanals, alk-2-enals, alk-2,4-dienals, and 2-alkanones of carbon chain length up to C-13 was obtained in anhydrous tertiary hutyl alcohol. However, in practical applications in the presence of fat these reactions were greatly retarded and inhibited.Modification by the use of water in the reaction gave quantitative recovery of aldehyde homologous series from the fat. Quantitative or even uniform recovery of 2-alkanones could not be obtained.Optimum reaction with the Girard T reagent was at room temperature, and refluxing tended to decrease yields. Girard T hydrazones were. converted quantitatively to 2,4-dinitrophenylhydrizones. The method is useful for the determination of aldehydes generated in autoxidized fats.

Characterization of some volatile constituents of carrots

“…A third group of compounds were carbonyls, mostly aliphatic aldehydes. These were detected in the capillary GLC-mass spectral analysis of the oxygenated fraction but it was found advantageous to separate the carbonyls with Girard T reagent using a procedure similar to that described by Gaddis et al (1964). The components were separated on a 500-foot long X 0.3-inch I.D.…”

Carbonyls in oxidizing fat. X. Quantitative differences in individual aldehydes isolated from autoxidized lard by mild methods of extraction

“…The comparisons made indicate that the Girard T method as developed by Gaddis et al (8) extracts the lowest amounts of individual monocarbonyl compounds from autoxidizing lard. It would appear that it is superior in this respect to vacuum distillation and the Schwartz method.…”

“…Simultaneous determinations on duplicate 10.0 g samples were made at peroxide values of 29, 58, 119, and 256. Isolations of carbonyl 2,4-dinitrophenylhydrazones by vacuum distillation, Girard T, and Schwartz methods, separation of the monoearbonyl derivatives by column chromatography, resolutions into classes and individual compounds by paper chromatography and measurement of the various fractions by speetrophotometry at k max were performed as described in earlier publications (1,2,4,5,(8)(9)(10). The Pool and Klose method as modified by Keith and Day (11) was applied to all samples as a reference indicating the reservoir of monoearbonyl precursors present.…”

“…The importance of isolation of free monocarbonyl compounds in flavor studies has been amply discussed (6,9,10,13). Quantitatively comparable mild methods (9), such as the pot still vacuum distillation of Lea and Swoboda (12), Girard T (8), and the Schwartz (15) procedures, have been proposed for the isolation of free aldehydes. These methods were found to differ at one or more of two apparent stages of autoxidation in total monoearbonyl compounds and proportions of classes (9).…”

Analysis of fat deterioration‐comparison of some photometric tests

“…Colour Developer 3: [N-2-[N-aethyl-N-(4-amino-3-methylphenyl)-amino} -aethy-methansulfonamidsesquisulfate, was from Mercl~ (Darmstadt, Germany). Carbonyl free solvents were prepared by the methods of Schwarz and Parks (5) and Gaddis et al (6).…”