分散液相微萃取气相色谱/气相色谱质谱法测定白洋淀水中多溴联苯醚

Determination of Polybrominated Diphenyl Ethers in Baiyang Lake by Dispersive Liquid-Liquid Microextraction and Gas Chromatography/Gas Chromatography-Mass Spectrometry

建立了分散液相微萃取(DLLME)与气相色谱-微池电子捕获检测器(GC-μECD)、气相色谱-质谱(GC/MS)联用快速测定水样中42种多溴联苯醚(PBDEs)的新方法。以氯苯(25μL)为萃取剂,乙腈(1.0mL)为分散剂,混匀后注入5.00mL水样中,以3000r/min离心15min,取出下层有机相氮气吹干、定容后取1μL进样分析。在最佳条件下,PBDEs能够被充分提取和良好分离,在2.0～250.0μg/L浓度范围内呈现良好的线性关系,线性相关系数为0.9982～0.9999;检出限为0.2～4.9μg/L(S/N=3)。将本方法应用于白洋淀水中PBDEs的分析检测,样品中均有BDE-166和BDE-209的检出,对水样进行两个浓度水平(0.017和0.170μg/L)的加标实验,回收率为71.4%～110.8%,相对标准偏差为0.99%～11.84%(n=3),能够满足环境水样中痕量PBDEs的测定要求。

Dispersive liquid-liquid microextraction（DLLME） is a very simple and rapid method for the extrac-tion and preconcentration of polybrominated diphenyl ethers（PBDEs） in water samples.Approximately 42 PBDEs were extracted by DLLME and determinated by gas chromatography coupled with the micro-electron capture detector（GC-μECD） and gas chromatography-mass spectrometry.In this method,the mixture of chlorobenzene（25μL） and acetonitrile（1.0 mL） were injected into samples rapidly,then centrifugated for 15 min at 3000 r/min,after that the organic phase was drawn from the centrifuge tube and evaporated to dryness by nitrogen.The residue was dissolved by 17μL acetone,and 1μL was injected into the GC.Under the optimized conditions,PBDEs can be extracted completely and separated well.Good linear relationships were obtained in the concentrations of 2.0-250.0μg/L of the analyte with the correlation coefficients of 0.9982-0.9999.The limits of detection were between 0.2 and 4.9 ng/L（S/N=3） .The water samples collected from Baiyang Lake were successfully analyzed using the proposed method.BDE-166 and BDE-209 were detected in all water samples.The recoveries,which had been spiked with different levels（0.017 and 0.170μg/L） ,fell in the range of 71.4%-110.8%and the relative standard deviations were between 1.0% and 11.9%（n=3） .The results showed that the proposed method would be valuable for PBDEs analysis in environmental water samples.