超声辅助分散液-液微萃取-火焰原子吸收光谱法测定水样中的痕量锌

Ultrasound-assisted dispersive liquid-liquid microextraction combined with flame atomic absorption spectrometry for determination of trace zinc in water samples

建立了以1-（2-吡啶偶氮）-2-萘酚（PAN）为配位剂、四氯化碳为萃取剂的超声辅助分散液-液微萃取-火焰原子吸收光谱法测定水样中痕量锌的新方法。对萃取剂进行了筛选,并研究了pH、PAN的用量、萃取温度、萃取时间等试验条件对萃取效率的影响。在优化条件下,富集5.0 mL样品溶液,锌的检出限为0.95μg/L,富集倍率为12.5,线性范围10.0~450.0μg/L,相对标准偏差（RSD）为3.55%。本方法应用于自来水、河水及海水中痕量锌的分析,加标回收率在92.4%~101.5%。

The process of ultrasound-assisted dispersive liquid-liquid microextraction（USADLLME） was successfully applied for the extraction and preconcentration of trace zinc from water samples,prior to flame atomic absorption spectrometry（FAAS）.In the proposed approach,1-（2-pyridylazo）-2-naphthol（PAN） was used as a chelating agent and carbon tetrachloride was selected as extraction solvent.Some effective parameters on the microextraction and the complex formation were selected and optimized.These parameters included extraction solvent type,extraction time,extraction temperature,pH and the amount of the chelating agent.Under optimum conditions,an enrichment factor of 12.5 was obtained from only 5.0 mL of water sample.The calibration graph was linear in the range of 10.0-450.0 μg/L with a detection limit of 0.95 μg/L.The relative standard deviation（RSD） for eleven replicate measurements of 300 μg/L of zinc were 3.55%.The method was applied to the analysis of tap,river,and sea water samples and good spiked recoveries over the range of 92.4-101.5% were obtained.