在市场上的固体和液体饮料中 ,许多生产厂家为了防止其中成分变质和腐败 ,使用一些防腐剂如苯甲酸和山梨酸等 ;为了增加甜度 ,有时也使用一些甜味剂如糖精等。这些添加剂多数存在一定的毒性〔1〕。在食品卫生检查中 ,为了判断食品中是否含有这些添加剂 ,通常采用薄层分析法〔2 In solid and liquid beverages on the market, many manufacturers use preservatives such as benzoic acid and sorbic acid to prevent deterioration and spoilage of the ingredients. Some sweeteners such as saccharin are sometimes used to increase the sweetness. Most of these additives have some toxicity 〔1〕. In the food hygiene inspection, in order to determine whether the food contains these additives, usually by thin layer analysis [2