气相色谱质谱法测定植物油中3-氯丙醇酯的影响因素研究

Factors influencing determination of 3-chloropropane esters in vegetable oil by gas chromatography-mass spectrometry

目的对影响植物油中3-氯丙醇酯气相色谱质谱法测定结果准确性的因素进行分析,提出有效的控制措施,使测定结果准确。方法采用气相色谱质谱法,通过定量离子优化选择、乙醚重蒸、吸附剂和脱水剂烘烤处理来提高3-氯丙醇酯测定结果的准确性。结果采取m/z 453为定量离子、将乙醚重蒸、吸附剂和脱水剂于500℃烘烤3 h控制措施后,3-氯丙醇酯测定的工作曲线相关系数为0.9995,试剂空白和阴性植物油样的测定值均小于方法检出限,FAPAS分析实验室能力验证样品的两次检测结果均在参考值范围内,相对偏差为4.6%。结论本研究找出了气相色谱质谱法测定植物油中3-氯丙醇酯的影响因素,选择m/z 289为定量离子影响3-氯丙醇酯色谱峰峰面积的积分准确性,定量离子m/z453则不存在干扰。乙醚、吸附剂和脱水剂中含有3-氯丙醇本底,对植物油中3-氯丙醇酯的测定有影响,需纯化后使用。

Objective To analyze the factors influencing the accuracy of determination Results of 3-chloropropane esters in vegetable oil by gas chromatography mass spectrometry so as to put forward effective control measures for acquiring accurate determination results. Methods Gas chromatography-mass spectrometry was used to determine 3-chloropropane esters in vegetable oil samples with pretreatment, including suitable quantitative ion selection, ether purification and adsorbent and dehydrant baking. Results After selecting quantitative ion m/z 453, purifying ether and baking adsorbent and dehydrant under 500℃ for 3 hours, the correlation coefficient of working curve was 0.9995, and the determination values of reagent blank and negative vegetable oil samples were all less than the detection limits. The levels of two parallel determination of 3-chloropropane esters in proficiency testing samples from Food Analysis Performance Assessment Scheme （FAPAS） were both within the acceptable range, and the relative standard deviation （RSD） was 4.6%. Conclusions We find the key factors influencing determination of 3-chloropropane esters in this study. The chromatographic peak area of 3-chloropropane esters can not be integrated accurately when selecting m/z 289 as quantitative ion, but no interference exists using m/z 453. The background of 3-chloropropanol, which exists in ether, adsorbent and dehydrant, can affect the determination of 3-chloropropane esters in vegetable oil samples,so it must be purified.