目的 建立气相色谱-串联质谱法(gas chromatography-tandem mass spectrometry,GC-MS/MS)测定火锅底料中邻苯二甲酸酯类塑化剂[邻苯二甲酸二正丁酯(dibutyl phthalate,DBP)和邻苯二甲酸(2-乙基)己酯(di(2-ethylhexyl)phthalate,DEHP)]的分析方法.方法 样品加入少量正己烷溶解,经乙腈超声提取,低温离心,取乙腈层浓缩干正己烷定容,通过HP-5MS UI色谱柱(30.0 m×0.25 mm,0.25 μm)分离,多反应监测(multiple reaction monitoring,MRM)模式扫描,同位素内标法定量.结果 在 0~1.00 μg/mL质量浓度间,DBP和DEHP线性良好(r>0.999),定量限分别为 0.05 mg/kg、0.04 mg/kg,在低、中、高的 0.20、0.30、0.50、1.00 和 2.00 mg/kg 5种浓度下的加标回收率均在95.5%~108.1%,相对标准偏差均在0.43%~3.70%,满足相关检测要求.结论 本研究在国家标准的基础上优化前处理过程,采用三重四极杆串联质谱法,提升仪器的特异性,建立了一种简单、操作性强且适用于基质复杂的火锅底料的DEHP和DBP塑化剂的定量分析方法,同时发现塑化剂在火锅底料这类油脂类食品中存在明显的污染.
Objective To establish an analysis method for the determination of phthalate ester plasticizers[dibutyl phthalate(DBP)and di(2-ethylhexyl)phthalate(DEHP)]in hotpot seasoning by gas chromatography-tandem mass spectrometry(GC-MS/MS).Methods The sample was dissolved by a small amount of n-hexane,ultrasonically extracted by acetonitrile,centrifuged at low temperature,dried acetonitrile layer with nitrogen,and separated by HP-5MS UI chromatographic column(30.0 m×0.25 mm,0.25 μm),scanned with multiple reaction monitoring(MRM)mode,quantified by isotope internal standard method.Results The linear relationship of the DBP and DEHP was good in the concentration range of 0-1.00 μg/mL(r>0.999),and the limits of quantitation were 0.05 mg/kg,0.04 mg/kg,respectively.At different concentrations of 0.20,0.30,0.50,1.00,2.00 mg/kg,the standard recoveries were 95.5%?108.1%,with the relative standard deviations were 0.43%?3.70%,which met the requirements of analysis and testing.Conclusion In this study,the pretreatment process has been optimized on the basis of national standards,and triple quadrupole tandem mass spectrometry has been used to improve the specificity of the instrument,a simple and operational quantitative analysis method has been established,which is suitable for the quantification of DEHP and DBP of hotpot seasoning with complex matrix,meanwhile,plasticizer has obvious pollution in fat food such as hotpot seasoning.