固相萃取结合超高效液相色谱-串联质谱法及气相色谱-负化学源质谱法测定人血清中的四溴双酚A、六溴环十二烷和多溴联苯醚

建立了固相萃取同时提取、净化血清中四溴双酚A(TBBPA)、α, β, γ-六溴环十二烷(HBCD)和8种多溴联苯醚(PBDEs)同系物的样本前处理方法,并结合色谱-质谱分离分析技术检测人血清样本中该类化合物的含量。试样在加入各自的同位素内标物后以甲基叔丁基醚/正己烷(1:1, v/v)混合溶剂进行萃取,再经浓硫酸去除脂肪后,以LC-Si固相萃取柱分离HBCD/TBBPA和PBDEs。采用分步检测的方式,在50 mm长BEH C18反相色谱柱上以超高效液相色谱-串联质谱(UPLC-MS/MS)的多反应监测模式(MRM)检测HBCD和TBBPA,在15 m长的毛细管柱上以气相色谱-负化学源质谱(GC-NCI/MS)的选择离子监测模式(SIM)检测PBDEs。以胎牛血清为空白基质,当HBCD、TBBPA和BDE-209的加标水平为0.5 ng/g和5 ng/g、三溴至七溴联苯醚的加标水平为0.05 ng/g和0.5 ng/g时,它们的平均加标回收率为80.3%～108.8%,相对标准偏差为1.02%～11.42%(n=5);以信噪比(S/N)为3计算,方法的检出限(LOD)为1.81～42.16 pg/g。采用该方法对实际样品进行测定,结果表明,本方法快速、准确、灵敏度高,能够满足血清中HBCD、TBBPA和PBDEs残留的同时提取及测定的要求。

Determination of three brominated flame retardants in human serum using solid-phase extraction coupled with ultra-performance liquid chromatography-tandem mass spectrometry and gas chromatography-mass spectrometry

A solid-phase extraction (SPE) method for the simultaneous extraction of hexabromocyclododecanes (HBCDs)/tetrabromobisphenol A (TBBPA) and polybrominated diphenyl ethers (PBDEs) in human serum was developed. The extracts of HBCDs/TBBPA and PBDEs were determined using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) and gas chromatography-negative chemical ionization/mass spectrometry (GC-NCI/MS), respectively. The samples with the spiked internal standards, 13C(12)-HBCD, 13C(12)-TBBPA, 3, 3', 4, 4'-tetrabromodiphenyl ether (BDE-77) and 13C(12)-decabromodiphenyl ether (BDE-209), were extracted using the mixture of methyl tert-butyl ether (MTBE) and hexane (1:1, v/v). Then the co-extracted lipid was removed by sulfuric acid treatment. The newly obtained extract was purified using SPE with an LC-Si column and two fractions of HBCDs/TBBPA and PBDEs were finally got. The determination of HBCDs/TBBPA was performed on a 50 mm BEH C18 column in the multi-reaction monitoring (MRM) mode and the determination of PBDEs was on a 15 m capillary column in the selected ion-monitoring (SIM) mode. The limits of detection (LODs, S/N = 3) ranged from 1.81 to 42.16 pg/g. The average recoveries were from 80.3% to 108.8% at two spiked levels of 0.5 and 5 ng/g for HBCDs, 0.05 and 0.5 ng/g for TBBPA and BDE-209 with the relative standard deviations between 1.02% and 11.42% (n = 5). The developed method has been successfully applied to the determination of the 12 analytes in 42 pooled human serum samples. The levels of TBBPA in the samples ranged from < LOD to 6.58 ng/g, that of alpha-HBCD diastereoisomer ranged from < LOD to 7.22 ng/g, which was the most abundant isomer comparing with beta- and gamma-HBCD. The total PBDEs found ranged from 2.90 to 89.69 ng/g. This method was validated to be accurate and sensitive for the analysis of HBCDs, TBBPA and PBDEs in serum samples.