超高效液相色谱-串联质谱法同时测定食品级聚苯乙烯和聚乙烯色母粒中33种初级芳香胺

摘要

建立了超高效液相色谱-三重四极杆质谱（ UPLC-MS／MS）同时测定食品级聚苯乙烯（ PS）和聚乙烯（ PE）色母粒中33种初级芳香胺（ PAAs）的检测方法。PS色母粒用二氯甲烷溶解，超声提取后加入甲醇沉淀，并将提取液过石墨化碳固相萃取柱净化；PE色母粒用二氯甲烷超声溶胀提取；将 PS 色母粒过柱液和 PE 色母粒提取液浓缩，浓缩液用甲醇-水（1：9，v／v）定容至2 mL，0.22μm膜过滤后上机检测。采用 BEH Phenyl色谱柱（100 mm ×2.1 mm，1.7μm），以0.07％（v／v）甲酸甲醇溶液-水（1：9，v／v）为流动相，梯度洗脱分离，UPLC-MS／MS 多反应监测（ MRM）模式检测，同位素内标法定量。优化了色谱分离条件、质谱碎裂电压、碰撞能量等，并考察了提取时间、提取溶剂、浓缩方式等对回收率的影响。33种 PAAs的方法检出限为6~10μg／kg，定量限为20~30μg／kg，2种不同基质样品在20、100、200μg／kg等3个添加水平的平均回收率为61.3％~119.8％，相对标准偏差（ RSD）为1.4％~14.8％。本方法操作简便、快速、准确、灵敏度高，能满足相关测定要求。%A comprehensive analytical method based on ultra-performance liquid chromatogra-phy coupled with triple quadrupole mass spectrometry( UPLC-MS/MS)has been developed for the simultaneous determination of 33 primary aromatic amines( PAAs)in polystyrene( PS)and polyethylene( PE)masterbatches for foods. The PS masterbatches were dissolved with dichlo-romethane,and methanol was added to precipitate after extraction by ultrasound extraction. Then the extract was purified by passing through a carbon graphite solid phase extraction col-umn. The PE masterbatches were swelled and extracted with dichloromethane by ultrasound. The purified PS solution and PE extract were concentrated,and diluted to 2 mL with methanol-water(1:9,v/v),and filtered through the membranes of 0. 22 μm before UPLC-MS/MS analy-sis. The analytes were separated on a BEH Phenyl column(100 mm×2. 1 mm,1. 7 μm),eluted by gradient with 0. 07%( v/v ) formic acid in methanol-water( 1 :9,v/v ). The PAAs were detected by UPLC-MS/MS under multiple reaction monitoring( MRM )mode and quantified by the internal standard method. The separation conditions,fragment voltages and collision ener-gies were optimized. The impacts of extraction times,extraction solvents and concentration methods on recoveries were studied. The limits of detection for the 33 primary aromatic amines were 6—10 μg/kg,and the limits of quantitation were 20—30 μg/kg. The mean recoveries of the two different masterbatch products at three spiked levels of 20,100,200 μg/kg were 61. 3%—119. 8%,and the relative standard deviations were 1. 4%—14. 8%. The experimental results indi-cated that the method is simple,rapid,sensitive,accurate,and can meet the related require-ments for determination.