多同位素内标气相色谱-质谱法测定食品中4种氯丙醇含量

Determination of 4 Kinds of Chloropropanols in Foods by Gas Chromatography-Mass Spectroscopy Coupled with Multi-Isotopic Internal Standard Technique

采用多同位素内标法，结合七氟丁酰基咪唑（HFBI）衍生化的气相色谱-质谱（GC—MS）联用技术，建立了食品中4种氯丙醇含量的检测方法。对比了不同来源HFBI衍生试剂的作用性能，对定量内标物和校正标准的选择进行了比较。结果表明：仅用2种同位素内标（3．氯-1，2．丙二醇-d5（或2．氯．1，3．丙二醇．d，）和1，3．二氯．2．丙醇-d5）校正，同样可达到准确测定食品中4种氯丙醇含量的要求；若采用3-氯-1，2-丙二醇（3-MCPD）为标准物定量测定2-氯-1，3-丙二醇（2-MCPD）时，所得2-MCPD结果偏低，仅为以2．MCPD为标准物定量结果（真实值）的52．1％-77．8％。在最佳条件下进行了方法学指标的系统验证。4种氯丙醇的最低检出限为2．5～10gg／kg：在100-2000ng范围内，氯丙醇与内标物峰面积的比值和质量呈线性关系俾z〉0．9990）。以酱油和方便面调料粉为基质，进行100、200、4001xg／kg-1．个水平的加标回收实验，4种氯丙醇的回收率均值为90．1％～107％，相对标准偏差（RSD）为3．37％～10．4％（n=6），均满足痕量分析的要求。

An analytical method was developed to determine 4 kinds of chloropropanols in foods using gas chromatography mass spectrometer coupled with the multi-isotopic internal standard technique. The performance difference between different brands of HFBI as a derivativization reagent and internal standard selection for quantification were discussed. Under the optimal conditions, the limits of detection （LOD） were 2.5-10 gg/kg for 4 kinds of chloropropanols. According to the internal standard calibration, an excellent linearity between 100 ng and 2000 ng of chloropropanols （R2 〉 0.9990） was obtained. When chloropropanols were spiked at levels of 100, 200, 400 mg/kg in soy sauce and seasoning powder of instant noodles, the average recovery rates were 90.1%-107%, with relative standard deviation （RSD） of 3.37%-10.4% （n = 6）. The application of only 2 kinds of internal standards （chloropropane-l,2-diol-d5 or 2-chloropropane-l,3-diol-d5 and 1,3-dichloro-2-propanol-ds） can reveal accurate and precise determination for 4 kinds of chloropropanols. When 3-chloropropane-l,2-diol （3-MCPD） was used to calibrate 2-MCPD in foods, the level of 2-chloropropane-1,3-diol （2-MCPD） was only 52.1%-77.8% of the real content.