食品中环己基氨基磺酸钠-气相色谱法测定原理探讨

本实验对国标法GB/T5009.97-2003《食品中环己基氨基磺酸钠的测定》中气相色谱法的原理进行探讨.运用GC-MS可直接对反应产物进行定性的特点,比较了国标方法(后加氯化钠)、国标方法(先加氯化钠)、静态顶空法(不加氯化钠)和静态项空法(加氯化钠)四部分实验,从而对测定原理进行推断.结果显示无论何种条件下均无环己醇亚硝酸酯生成(提取环己醇亚硝酸酯的特征离子98、82、57),且反应产物不单一,在没有Cl-存在的情况下,主要产物有环己烯、物质X及环己醇;在Cl-存在的情况下,反应产物较为复杂,有环己烯、物质X、环己醇及各种氯代环己烷.研究认为此反应主要是脂肪伯胺的重氮化反应.

Discussion on Determination Principle of Sodium Cyclamate in Foods by Gas Chromatography

The determination principle of sodium cyclamate in foods-gas chromatography was confirmed and discussed. GC- MS was used to identify resultants in four experiments. The first experiment was the national standard method in which sodium chloride was added to the reaction system after the reaction was over. The second was the national standard method in which sodium chloride was added to the reaction system as reagent. The third was headspace method in which there was not sodium chloride. The fourth was headspace method in which sodium chloride was added to reaction system as reagent. At last, the principle of reaction was concluded by comparison of the four experiments. There was no nitrous acid cyclohexyl ester to generate in the four experiments. When there was not Cl^- in the reaction system, the primary resultants were cyclohexene, X and cyclohexenol. When Cl^- existed, besides cyclohexene, X and cyclohexenol, there were various chlorocyclohexanes. Author believes that reaction is primary amine diazotization.