提出了分散固相萃取-气相色谱-串联质谱法测定液态调味品中3-氯-1,2-丙二醇(3-MCPD)、2-氯-1,3-丙二醇(2-MCPD)、1,3-二氯-2-丙醇(1,3-DCP)和2,3-二氯-1-丙醇(2,3-DCP)等4种氯丙醇类化合物含量的方法。取样品2.0 g,加入一定量的同位素内标混合溶液,混匀,然后加入2 mL甲醇、1 g无水硫酸钠、100 mg C₁₈、100 mg N-丙基乙二胺,涡旋,离心,沉淀中再加入2 mL甲醇重复提取一次。合并上清液,用甲醇定容至5 mL,过0.22 μm有机针式滤头,滤液按照仪器工作条件进行测定。4种氯丙醇类化合物及其内标在DB-WAX色谱柱上经柱升温程序分离,电子轰击离子源电离,以多反应监测模式检测,内标法定量。结果表明:4种氯丙醇类化合物标准曲线的线性范围均为1~1 000 μg·L^-1,检出限(3S/N)为0.002~0.005 mg·kg^-1;对空白样品进行3个浓度水平的加标回收试验,回收率为66.6%~102%,测定值的相对标准偏差(n=6)为0.72%~8.8%。方法用于酱油、蚝油、鱼露、香醋、豆瓣酱等70份液态调味品分析,结果显示:1,3-DCP和2,3-DCP均未检出;2-MCPD检出量为0.005~0.138 mg·kg^-1,检出率为41.4%;3-MCPD检出量为0.005~0.954 mg·kg^-1,检出率达到100%,并且有部分样品的3-MCPD检出量超出GB 2762-2017规定的限量要求。

A method for the determination of chloropropanols including 3-chloro-1,2-propanediol (3-MCPD), 2-chloro-1,3-propanediol (2-MCPD), 1,3-dichloro-2-propanol (1,3-DCP) and 2,3-dichloro-1-propanol (2,3-DCP) in liquid condiments by gas chromatography-tandem mass spectrometry with dispersive solid phase extraction was proposed. The sample (2.0 g) was taken, and a certain amount of isotope internal standard mixed solution was added. After mixing well, 2 mL of methanol, 1 g of anhydrous sodium sulfate, 100 mg of C₁₈ and 100 mg of N-propyl ethylenediamine were added, and the mixture was swirled and centrifuged. Methanol (2 mL) was added into the obtained precipitation for repeated extraction, and the supernatants were combined, and made its volume up to 5 mL with methanol. The solution was filtered through 0.22 μm organic needle filter, and the filtrate was determined according to the operating conditions of the instrument. Four chloropropanols and their internal standards were separated on DB-WAX column by column heating program, ionized by electron impact ion source, detected by multi-reaction monitoring mode, and quantified by internal standard method. It was shown that the linear ranges of standard curves for 4 chloropropanols were 1-1 000 μg·L^-1, with detection limits (3S/N) in the range of 0.002-0.005 mg·kg^-1. Test for recovery was made on blank sample by standard addition method at 3 concentration levels, giving results in the range of 66.6%-102%, and RSDs (n=6) of the determined values ranged from 0.72% to 8.8%. This method was applied to the analysis of 70 liquid condiments including soy sauce, oyster sauce, fish sauce, balsamic vinegar and bean paste. It was shown that 1,3-DCP and 2,3-DCP were not detected, and detected amounts of 2-MCPD and 3-MCPD were in the ranges of 0.005-0.138 mg·kg^-1 and 0.005-0.954 mg·kg^-1, with detection rates of 41.4% and 100%, respectively. The detected amount of 3-MCPD in some samples exceeded the limit requirements stipulated in GB 2762-2017.