Extraction of organic acids by ion-pair formation with tri-n-octylamine. Part 7. Comparison of methods for extraction of synthetic dyes from yogurt.

M L Puttemans, M de Voogt, L Dryon, D Massart

Index: J. Assoc. Off. Anal. Chem. 68(1) , 143-5, (1985)

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Abstract

Synthetic dyes were extracted from yogurt by different methods, but all methods had in common a liberation of dyes from the food followed by ion-pair formation with tri-n-octylamine. Extraction with pH 5.5 phosphate buffer gave high recoveries for 5 of the 7 dyes investigated and was relatively fast. Precipitation of proteins followed by polyamide adsorption and desorption gave high yields for all the dyes but was tedious and long.