离子色谱-质谱联用技术测定饮用水及环境水样中的痕量高氯酸盐

Determination of trace perchlorate in drinking water and environmental water samples by Ion chromatography-electrospray tandem mass spectrometry

建立了一种测定痕量高氯酸盐的离子色谱-质谱联用方法。选用高容量、强亲水性的阴离子交换柱IonPac AS20(2mm)进行分离,以淋洗液自动发生器在线产生的KOH为淋洗液,采用等浓度淋洗。在不添加有机溶剂的情况下,淋洗液经过抑制器抑制后直接进入电喷雾-串联质谱(ESI-MS-MS),以负离子模式进行检测。同时采用多元反应监测(MRM)模式对高氯酸盐进行监控,以100.8/84.9、98.8/66.9和100.8/68.9为监控离子对,以98.8/82.9离子对的峰面积进行定量。高氯酸盐质量浓度在0.05～50μg/L范围内具有良好的线性(r=0.9985),检出限(S/N=3)为0.01μg/L。将该方法用于饮用水以及地下水、雪水等环境水样中高氯酸盐的分析,并进行了加标回收实验,回收率在86%～110%之间,将实际自来水样品连续11次进样,所得高氯酸盐的峰面积的相对标准偏差(RSD)为1.6%。

In this paper the ion chromatography-electrospray tandem mass spectrometry （IC-ESI-MS-MS） was developed for the determination of perchlorate in drinking water and environmental water.Perchlorate was separated with high capacity and hydroxide selective column using KOH eluent generating on-line from EGC.ESI-MS-MS detection was performed by the negative electronspray ionization and multiple reaction monitoring （MRM） mode.The transition of 98.8/82.9 was monitored for quantifying the main analyte.The transition 100.8/84.9,98.8/66.9 and 100.8/68.9 were monitored for confirmation.The detection limit of perchlorate was as low as 0.01 μg/L.The method was applied to the detection of perchlorate in tap water,ground water and snow water.The recoveries of spiked standard were in the range of 86%～110%.RSD of the peak area for the eleven successive injections of tap water was 1.6%.