Abstract：
This study presents a method based on acid transesterification and the purification by solid-phase extraction (SPE) coupled with gas chromatography-tandem mass spectrometry for quantifying 3- and 2-monochloropropanediol esters (3-MCPDE, 2-MCPDE) and glycidyl esters (GE) in nutritional foods. The fat was extracted by liquid-liquid extraction with petroleum ether and diethyl ether after the sample was hydrolysed with ammonia. Then the extract was purified by a SPE cartridge filled with the aminopropyl sorbents. It was demonstrated that the optimal elution volume for 3-MCPDE, 2-MCPDE and GE greatly depended on the sample matrix and varied from 6 to 12 mL for four different kinds of food matrices. All three analytes in the sample solution could be fully collected in the first 10-12 mL of eluate. By this way, monoacylglycerols commonly present in the samples were fully removed. Therefore, the overestimation of GE quantification was effectively eliminated. The modified analytical procedure was fully validated in a single laboratory and has been recommended as a Chinese Food Safety National Standard. In addition, two derivatisation agents, heptafluorobutyrylimidazole and phenylboronic acid, were proved to be equivalent in method accuracy and precision for the quantification of three analytes.
摘要：
这项研究提出了一种基于酸酯交换和固相萃取（SPE）结合气相色谱-串联质谱法纯化的方法，用于定量3-和2-一氯丙二醇酯（3-MCPDE，营养食品中的2-MCPDE）和缩水甘油酯（GE）。样品用氨水水解后，用石油醚和乙醚液-液萃取法提取脂肪。然后通过填充有氨基丙基吸附剂的SPE柱纯化提取物。结果表明，3-MCPDE的最佳洗脱体积，2-MCPDE和GE很大程度上取决于样品基质，对于四种不同的食物基质，2-MCPDE和GE在6至12mL之间变化。样品溶液中的所有三种分析物可以完全收集在最初的10-12mL洗脱液中。通过这种方式,样品中通常存在的单酰基甘油被完全去除。因此,有效消除了对GE定量的高估.修改后的分析程序在单个实验室中得到了充分验证，并被推荐为中国食品安全国家标准。此外,两种衍生剂，七氟丁咪唑和苯基硼酸，被证明在定量三种分析物的方法准确性和精密度方面是等效的。
