A Simple Method for the Separation and Identification of Coal-Tar Dyes in Foods

Abstract

A rapid and simple method was devised for the separation and identification of coal-tar dyes in foods by means of partition column chromatography. Outline of the experiments carried out is as follows.
(1) About 1g of the sample was mixed with 4g of silica gel and required amount of anhydrous sodium sulfate.
(2) The mixture was packed in a glass column of 1.4cm in diameter (stoppered with cotton to the bottom of the column), above the adsorbent (alumina: synthetic zeolite 4: 1) of a 10cm layer (see Fig. 1).
(3) The column thus prepared was subjected to partition chromatography by the descending method using the mixture of acetone, isoamyl alcohol, water and methyl cellosolve (6: 5: 5: 2) as a solvent.