固相萃取-气相色谱-三重四极杆串联质谱法同时测定蟹肉中六种胆固醇氧化物

Simultaneous determination of six cholesterol oxides in crab meat by solid phase extraction-gas chromatography-triple quadrupole tandem mass spectrometry

建立了固相萃取-气相色谱-三重四极杆串联质谱法同时测定蟹肉中6种胆固醇氧化物(cholesterol oxides,COPs)的方法。确定了以V(甲醇)∶V(氯仿)=1∶2混合溶液为提取剂;考察了3种固相萃取柱的净化效果,确定了利用Poly-Sery HLB固相萃取柱进行净化;对比了正己烷-乙醚、正己烷-乙酸乙酯和正己烷3种试剂的净化效果,选择了正己烷-乙醚为净化试剂;对比了乙腈、丙酮和乙酸乙酯3种洗脱剂的洗脱效果,采用丙酮为洗脱剂并确定洗脱体积为6 mL。洗脱后的样品经双(三甲基硅基)三氟乙酰胺衍生,设置合理的色谱工作条件,采用单离子检测质谱扫描模式,对6种COPs的主要离子进行检测。结果显示,6种COPs的工作质量浓度在0.2~10.0μg/mL内均与其对应的定量峰面积呈良好的线性关系,检出限为0.08~3.6 ng/g,平均回收率为77.64%~93.54%,相对标准偏差为2.34%~8.25%。该方法能满足蟹肉中COPs的定量分析。

An analytical method was developed for the simultaneous determination of six cholesterol oxides(COPs)in crab meat by solid-phase extraction-gas chromatography-triple quadrupole tandem mass spectrometry(SPE-GC-MS/MS).The extractant was a mixture of methanol and chloroform(1∶2,V/V).The clean-up effect of three different SPE columns was compared,and a Poly-Sery HLB solid phase extraction column was used.The clean-up effect of three clean-up reagents,namely,n-hexane-ethyl ether,n-hexane-ethyl acetate,and n-hexane,was compared,and n-hexane-ethyl ether was selected as the clean-up reagent.The elution effect of ethyl acetate,acetonitrile,and acetone was compared,acetone was selected as the eluent and the elution volume was determined to be 6 mL.The eluted samples were derivatized by bis(trimethylsilyl)trifluoroacetamide,and reasonable chromatographic working conditions were set up to detect the major ions of the six COPs using single ion detection mass spectrometry scanning mode.Results showed that the working concentrations of the six COPs were linear in the range of 0.2-10.0μg/mL with their corresponding quantitative peak areas,the limits of detection(LOD)were in the range of 0.08-3.6 ng/g,the average recoveries were 77.64%-93.54%and the relative standard deviations(RSD)were 2.34%-8.25%.The method can satisfy the quantitative analysis of COPs in crab meat.