超高效液相色谱/串联质谱法直接测定地表水中残留的恶喹酸

Direct determination of oxolinic acid in surface water by high performance liquid chromatography-tandem mass spectrometry

目前恶喹酸滥用所造成的环境污染问题已经引起国内外重视,但对环境地表水中恶喹酸残留的研究尚且不多。该文采用超高效液相色谱/串联质谱仪(HPLC-MS/MS),建立过滤后直接测定地表水中恶喹酸残留的分析方法。优化HPLC-MS/MS条件,用多反应监测(MRM)正离子扫描方式进行质谱检测,外标法定量。比较不同溶剂比例下色谱峰信号响应的差别,考察甲酸的加入对恶喹酸响应的影响,并研究基质效应对恶喹酸检测所起的作用。在0.13～78μg/L范围内进行定量分析,线性关系良好(r2>0.999),方法检出限为0.036μg/L。在1.04μg/L和3.9μg/L两个浓度进行加标回收,平均加标回收率为92.5%～94.8%,相对标准偏差为3.2%～5.2%。结果表明,该方法简单、快速、准确,适用于直接测定地表水中恶喹酸的残留。

The environmental pollution caused by the abuse of oxolinic acid has attracted attention both at home and abroad at present,however,the assay for the detection of oxolinic acid in environmental surface water still keeps challenging.A new method for directly detecting oxolinic acid residues after filter in environmental surface water by high performance liquid chromatography-tandem mass spectrometry(HPLCMS/MS)was established.HPLC-MS/MS conditions were optimized and the analysis was conducted in positive electrospray ionization and multiple reaction monitoring(MRM)mode.Performance indicators of the method were studied using external standard method by optimizing the percentage of methanol in solvent,the existence of formic acid in sample preparation and the interference of matrix in surface water.The results indicated that the method showed good linearity over the range of 0.13-78μg/L and the linear regression correlation coefficients of oxolinic acid was great(r2>0.999)under the optimal conditions.The detection limit was found to be 0.036μg/L.The average recoveries ranged from 92.5%to 94.8%at the spiked levels of 1.04μg/L and 3.9μg/L with the relative standard deviations(RSD)of 3.2%to 5.2%(n=10).This method was simple,fast and credible,and suitable for the direct determination of oxolinic acid residues in surface water.