固相萃取净化-气相色谱-三重四极杆串联质谱法同时测定奶粉中多氯联苯和邻苯二甲酸酯

建立了固相萃取净化结合气相色谱-三重四极杆串联质谱法同时检测奶粉中15种多氯联苯(PCBs)和16种邻苯二甲酸酯类化合物(PAEs)。通过对提取条件、净化方法、仪器条件等进行优化,样品经乙腈超声提取,固相萃取小柱净化后,由程序升温气化进样口不分流进样,选择反应监测模式检测。结果表明:PCBs和PAEs分别在5~1000μg/L和3~1000μg/L范围内呈良好的线性关系,相关系数(r^2)均不小于0.9922;方法检出限分别为0.5~3.0μg/kg和0.3~1.0μg/kg,定量限分别为1.5~8.0μg/kg和1.0~3.0μg/kg;实际样品的平均加标回收率分别为72.4%~94.8%和82.4%~107.1%,相对标准偏差均不大于9.1%(n=6)。该方法前处理简单、净化效果好、灵敏度和准确度高,可以实现对样品的同时净化和提取,能够满足实验室样品中多氯联苯和邻苯二甲酸酯的日常检测要求。

Determination of Polychlorinated Biphenyls and Phthalate Esters in Milk Powders by GC-MS/MS with Solid Phase Extraction

A method of gas chromatography-triple quadrupole mass spectrometry (GC-MS/MS) with solid phase extraction purification was developed for detecting 15 polychlorinated biphenyls (PCBs) and 16 phthalate esters (PAEs) residues in milk powders. The extraction conditions, purification methods and conditions of the samples were optimized. The samples were extracted with acetonitrile, cleaned up with solid phase extraction, detected by GC MS/MS under multiple reaction monitoring (MRM) mode, and quantified using external standard. The results showed that the calibration curves of PCBs and PAEs had good linear relationship in the range of 5 1 000 μg/L and 3 1 000 μg/L, respectively, with the correlation coefficients (r2) not less than 0992 2. The limits of detection (LODs) of PCBs and PAEs were 05 30 μg/kg and 03 10 μg/kg, and the limits of quantification (LOQs) were 15 80 μg/kg and 10 30 μg/kg, respectively. The average recoveries of the spiked samples were 724% 948% for PCBs and 824% 1071% for PAEs with RSD (n=6) less than 9.1%. This method is simple pretreatment, high sensitivity and high accuracy, PCBs and PAEs can be detected simultaneously, which can be used for daily detection of PCBs and PAEs in laboratory.