固相萃取/超高效液相色谱-串联质谱法快速测定不同水体中5种人造甜味剂、6种造影剂及咖啡因

建立了快速检测不同水样(地表水、污水处理厂进水和出水)中5种人造甜味剂、6种造影剂和咖啡因的超高效液相色谱-串联质谱(UPLC-MS/MS)方法。利用HR-X固相萃取柱对过滤后的水样进行富集净化。采用Zorbax SB-C_(18)色谱柱分离,电喷雾正模式(ESI+)和负模式(ESI-)下分别以乙腈-水(10 mmol/L乙酸铵,0.01%甲酸)和乙腈-水(5 mmol/L乙酸铵,1 mmol/L Tris)为流动相,多反应监测模式(MRM)检测。各目标化合物在5~5 000μg/L范围内线性关系良好,相关系数均大于0.998。地表水、污水处理厂进水和出水的回收率为70%~120%,相对标准偏差(RSD)为0.8%~19.0%,方法检出限(MDL)分别为0.43~13.8、1.80~34.8、2.30~134 ng/L。应用该方法对广州某污水处理厂进水和出水及受纳河流河水进行检测,除阿斯巴甜、碘他拉酸、碘普罗胺、碘美普尔外,其他物质均有检出且浓度较高。该方法准确、灵敏、操作简便,适用于多种环境水样中人造甜味剂、造影剂和咖啡因的分析检测。

Rapid Determination of Five Artificial Sweeteners,Six Iodinated X-ray Contrast Agents and Caffeine in Different Water Samples by Solid Phase Extraction with Ultra Performance Liquid Chromatography-Tandem Mass Spectrometry

An ultra performance liquid chromatography-tandem mass spectrometric (UPLC-MS/MS) method was developed for the rapid determination of 5 artificial sweeteners,6 iodinated X-ray contrast agents and caffeinein in various water samples (surface water,inflow and effluent for wastewater treatment plant).The filtered water samples were extracted,and purified through HR-X solid phase extraction cartridges and separated on a Zorbax SB-C18 column.The determination of analytes was performed under multiple reaction monitoring (MRM) mode using acetonitrile-water(10 mmol/L ammonium acetate,0.01％ formic acid) and acetonitrile-water (5 mmol/L ammonium acetate,1 mmol/L Tris) as mobile phases in positive ionization mode and negative ionization mode,respectively.The calibration curves of the target compounds were linear in the range of 5-5 000 μg/L with correlation coefficients more than 0.998.The recoveries of the target compounds in surface water,inflow and effluent were all between 70％ and 120％,with relative standard deviations (RSD) of 0.8％-19.0％.The method detection limits(MDL) for three types of water samples were in the ranges of 0.43-13.8 ng/L,1.80-34.8 ng/L and 2.30-134 ng/L,respectively.The method was successfully applied in the determination of artificial sweeteners,iodinated X-ray contrast agents and caffeine in different actual water samples collected from a wastewater treatment plant and its receiving river from Guangzhou city.Except for aspartame,iothalamic acid,iopromide and iomeprol,the other compounds were all detected with high concentrations.The established method is accurate,sensitive and simple,and is suitable for the determination of artificial sweeteners,iodinated X-ray contrast agents and caffeine in various environmental water samples.