本文係利用聚丙醯胺膠柱盤狀電泳法分析32種有色樣品中可能存在的水溶性酸性煤焦色素。由結果顯示此法之確合實際需要。其主要發現如下:
1.利用此法檢視之樣品，只需用水將色素溶出，不必要濃縮或其他繁瑣之前處理。而且不受醣質、果膠質及動物膠等物質之干擾。
2.所檢視之有色樣品中均含有一種以上的水溶性酸性煤焦色素。
3.大約三分之一以上的樣品含有最近禁用的食用紅色二號。
4.部分樣品含有同一系列之多種色素(如紅二、紅六及紅七並用)，又部分樣品含有太多而不必要的色素，均有待改進。
5.少數樣品含有少量法定外色素，本文曾就其中一種，進一步討論之。 We found that, most of water-soluble acid coal-tar dyes, which are presented in thirty two samples of foods and drugs, could be identified by polyacrylamide gel disc electrophoresis without further concentration of samples or other treatment. Some valuable conclusions were deduced from results obtained in this studies.
1. About one-third samples containing “Amaranth” (Red no. 2), which is not permitted now to be used in foods in several countries.
2. There are synthetic dyes of same color series (such as Red no. 2, Red no. 6, and Red no.7) presented in some samples. It is nonscence and unnecessary.
3. Some synthetic dyes, not permitted here are presented in a few of samples examined.
