固相萃取-气相色谱质谱法测定水中15种新型溴代阻燃剂的方法研究

Methodology for determination of 15 novel alternative flame retardants in water by solid phase extraction and gas chromatography-mass spectrometry

[背景]传统的溴代阻燃剂多溴联苯醚因对人类及动物具有健康危害而被禁用于商业产品中。新型溴代阻燃剂(NBFRs)作为其替代物逐渐被使用。NBFRs也存在潜在的健康危害,其暴露评估不容忽视。[目的]建立水中NBFRs的固相萃取-气相色谱质谱检测方法。[方法]NBFRs单标标样分别经电子轰击离子源(EI源)和负化学离子源(NCI源)的气相色谱-质谱联用仪进行准确定性,并优化质谱参数。固相萃取条件优化过程中,以二氯甲烷和正己烷(V∶V,1∶1)混合液为洗脱液,用20 LNBFRs的加标水样经XAD-2、XAD-8、C18吸附浓缩以选择吸附剂种类;并进一步优化合适吸附剂的洗脱次数。最后,进行方法学验证并将所建立的方法应用于上海市自来水和中国北方某农村地区地下水样品分析。[结果]NCI源对NBFRs的灵敏性优于EI源,XAD-2具有较好的吸附效能,洗脱4次时样品回收率可满足大体积水样分析的质控要求。NCI源对15种NBFRs的仪器检出限(IDL)范围为0.001~1.0 ng/mL,线性范围为0.005~200 ng/mL,决定系数(R2)范围为0.995 4~0.999 9。低、中、高质量浓度NBFRs加标水样回收率范围分别为62.3%~112.2%、61.1%~112.1%、65.4%~107.0%,精密度范围分别为1.5%~20.8%、1.0%~26.1%、0.7%~11.5%。NBFRs在上海市自来水和中国北方某农村地区地下水样均有不同程度的检出。[结论]该方法基本满足大体积水样中NBFRs检测的质量控制要求,并成功用于水样分析。

[Background] Traditional brominated flame retardants, polybrominated biphenyl ethers, have been prohibited from being used in commercial products because of their health hazards on human and animals. Novel brominated flame retardants(NBFRs) have gradually been used as substitution. Due to their potential health hazards, NBFRs exposure assessment cannot be ignored.[Objective] This methodological study aims to establish a method for determination of NBFRs in water by solid phase extraction and gas chromatography-mass spectrometry.[Methods] Each NBFR standard sample was separately qualitatively analyzed by gas chromatographyelectron impact ionization-mass spectrometry(GC-EI-MS) and gas chromatography-negative chemical ionization-mass spectrometry(GC-NCI-MS) to optimize parameters of mass spectrometry. In the optimization of solid phase extraction, the mixture of dichloromethane and hexane(V : V, 1 : 1) was used as elution solvents;the spiked water samples(20 L) of NBFRs were extracted using three kinds ofpacked columns, XAD-2, XAD-8, and C18, to select appropriate adsorbents. In addition, the elution times were optimized for packed columns with appropriate adsorbents. Finally, this proposed analysis protocol was validated and applied to the tap water samples collected from Shanghai and groundwater samples from a rural area in northern China.[Results] A higher sensitivity was found in identifying NBFRs by GC-NCI-MS than by GC-EI-MS. XAD-2 showed a good adsorption efficiency, and the recovery rate met the requirements for quality control of large-volume water sample analysis when the samples were eluted for four times. The instrument detection limit(IDL) of GC-NCI-MS was 0.001-1.0 ng/mL for 15 target chemicals;the linearity range was 0.005-200 ng/mL;the range of determination coefficients(R2) was 0.995 4-0.999 9. The recovery ranges of low-, mid-, high-concentration spiked water samples were 62.3%-112.2%, 61.1%-112.1%, and 65.4%-107.0%, respectively;and the relative standard deviations(RSD, n=5) were 1.5%-20.8%, 1.0%-26.1%, and 0.7%-11.5%, respectively. NBFRs were detected in the tap water samples from Shanghai and the groundwater samples from a rural area in northern China.[Conclusion] This method basically meets the requirements for analyzing NBFRs in large-volume water samples, and can be applied to water sample analysis.