DETERMINATION OF VOLATILE ALIPHATIC-ALDEHYDES IN THE HEADSPACE OF HEATED FOOD OILS BY DERIVATIZATION WITH 2-AMINOETHANETHIOL

Reaction conditions for the derivatization of volatile aliphatic aldehydes with 2-aminoethanethiol (cysteamine) were investigated. Reaction at room temperature for 1 h at pH 8 was sufficient and the recovery was quantitative for all the aldehydes tested. The detection limits were very low with a nitrogen-phosphorus detector. Concentration of the extract solution cannot be used because of the high volatility of the derivatization products, thiazolidines. Eleven aldehydes in the headspace of heated food oils were determined by this derivatization method. The concentration of hexanal was very high in all samples. It is noteworthy that the contents of isoalkanals were very low.