漩涡辅助液液微萃取和气相色谱法分析水样中甲草胺、乙草胺和丁草胺残留

Determination of metoalchlor,acetochlor and butachlor residues in water samples using vortex-assisted liquid-liquid microextraction and gas chromatography analysis

采用漩涡辅助液液微萃取技术作为前处理方法,气相色谱-微池电子捕获检测器作为色谱分析仪器,建立了水样中甲草胺、乙草胺和丁草胺3种酰胺类除草剂的残留分析方法。对影响微萃取效率的各种条件进行了优化,建立的微萃取条件为:在25mL容量瓶中,依次加入20mL水样和50μL甲苯,在2800r/min下漩涡1min。该方法线性范围在0.02～5μg/L之间,相关系数(R2)大于0.997。方法的富集倍数大于500倍。按照信噪比为3时估算的检出限在3.0～4.5ng/L之间(纯水),方法的报告限为0.05μg/L(自来水)和0.5μ/L(雪水)。使用该方法进行了自来水和雪水中的添加回收试验,在0.5,0.05μg/L添加水平,方法的添加回收率在74.2%～96.3%之间,相对标准偏差在4.9%～12.1%之间。

A vortex-assisted liquid-liquid microextraction (VALLME) has been developed and used for extraction amide herbicides from water samples,followed by gas chromatography micro-cell electron capture detection (GC-μECD).Experimental factors affecting the extraction efficiency were investigated.For the optimized VALLME method,aliquots of 50 μL toluene used as extraction solvent was directly injected into 20 mL water in a 25 mL volumetric flask.The extraction solvent dispersed into the water phase under vigorously...