氯消毒对水中草甘膦的降解性能研究

Study on the degradation of glyphosate in water by chlorine disinfection

目的分析草甘膦在经过氯消毒的饮用水中的分解情况,为农村及边远地区饮用水安全提供科学依据。方法配制总体积相同、草甘膦含量相同但余氯含量不同的系列混合溶液,溶液中草甘膦经超高效液相色谱柱富集分离后,与衍生试剂反应生成强荧光物质,以荧光检测器检测定量,经高效液相串联质谱联用仪进行确认。结果溶液中草甘膦与余氯经过1 h的反应,两者的含量为稳定值,表明草甘膦与余氯在1 h内已经完全反应达到平衡状态;随着余氯浓度的增大,草甘膦的含量逐渐减少直至全部分解,当溶液中余氯浓度大于1.3μg/ml时,溶液中草甘膦检测结果为未检出,经过高效液相色谱-串联质谱联用仪的确认,检测结果具有一致性。结论饮用水中余氯对草甘膦的分解有较大影响,农村及边远地区饮用水通过氯消毒可降低草甘膦对人体健康产生的危害。

Objective To analyze the decomposition of glyphosate in chlorinated drinking water, so as to provide scientific basis for safe drinking water in rural and remote areas. Methods A series of mixed solutions with the same total volume and same glyphosate content but different residual chlorine content were prepared. After the glyphosate in mixed solution was separated by ultra - high performance liquid chromatographic column, a strong fluorescent substance was generated with the reaction of the derived reagent. The glyphosate was detected by fluorescence detector and was confirmed by ultra - high per- formance liquid chromatography tandem mass spectrometry. Results The content of glyphosate and residual chlorine in so- lution was stable after 1 h of reaction. It indicated that glyphosate and residual chlorine had reached equilibrium within 1 h ; with the increase of residual chlorine concentration, the content of glyphosate gradually decreased until it was completely de- composed. When the residual chlorine concentration in the solution was greater than 1.3 μg/ml, the detection results of glyphosate in the solution were not detected. The results were consistent after confirmation by ultra - high performance liquid chromatography - tandem mass spectrometry. Conclusion The residual chlorine in drinking water has a great influence on the decomposition of glyphosate. Drinking water in rural and remote areas can reduce the harmful effects of glyphosate to hu- man health through chlorine disinfection.