在线固相萃取-液相色谱串联质谱法测定饮用水中的双酚A和壬基酚

An on-line solid phase extraction column switching liquid chromatography tandem mass spectrometry system to analyze bisphenol A and nonylphenol in drinking water

目的建立测定饮用水中双酚A(BPA)和壬基酚(NP)的在线固相萃取-液质联用法(On-line SPE LC-MS/MS)。方法水样经On-line SPE在线富集和净化,以甲醇-水为在线固相萃取流动相,流速2.0ml/min,采用沃特世Direct Connect HP XBridgeTMC18在线固相萃取柱(填料粒径10μm)进行在线固相萃取。以甲醇-0.1%氨水为分析流动相,流速0.4ml/min,采用沃特世UPLC BEH C18色谱柱进行分析。质谱检测器采用电喷雾电离源,以多反应监测(MRM)方式进行负离子监测,采用内标法对饮用水中的BPA和NP进行定量分析。结果该方法每个样品总耗时10min。BPA线性范围为5～1000ng/L,NP为10～5000ng/L,相关系数(r2>0.999)。BPA、NP的定量限(LOQ)分别为5和10ng/L,两种内分泌干扰物在3个加标水平下平均回收率为86.6%～105%,相对标准偏差3.11%～18.2%,日间精密度11.3%～13.2%。结论该方法实现了样品的自动化前处理,提高了分析效率,操作简单,灵敏度高,可用于饮用水中两种环境内分泌干扰物的痕量检测。

Objective To develop a method for bisphenol A （BPA） and nonylphenol （NP） analysis in drinking water by on-line solid phase extraction （SPE） column switching liquid chromatography tandem mass spectrometry. Method Target compounds were concentrated and purified by a Waters Direct Connect HP XBridgeTM C18column, with average particle size 10μm. The mobile phase of SPE extraction column was methanol/water at a flow-rate of 2.0ml/min. The analytical column was Waters BEH Cls column （2. lmm - 50mm,1.7μm） and the mobile phase was methanol/0. 1% ammonia water at a flow-rate of 0.4ml/min. BPA and NP were analyzed by liquid chromatographyelectrospray ionization tandem mass spectrometry （LC-ESI-MS/MS） in the negative ion mode with multiple reactions monitoring （MRM）. Results The whole run time of an individual sample was about 10 min. The linear calibration curves covered the range of5- 1000ng/L and 10 -5000ng/L for BPA and NP, respectively, while the correlation coefficients （r2） were above 0. 999. The quantification limits of the method were 5 and 10ng/L for BPA and NP, respectively. Recovery test was performed at three fortification levels, mean recoveries ranged from 86.6% to 105% with acceptable coefficients of variation （3.11% - 18.2% , n = 6）. The inter-day precisions were less than 13.2% Conclusion The established On-line SPE LC-MS/MS method needs no complicated sample pretreatment step, which is significantly time-saving. The analytical procedure is rapid, simple, and high-sensitive. It can be applied to analysis BPA and NP in drinking water.