A method for simultaneous preconcentration and determination of mercury species in water and soil samples was established using high-performance liquid chromatography with hydride generation atomic fluorescence spectrometry after ultrasound-assisted dual-cloud point extraction. The extraction process was divided into two steps. In the first cloud point extraction, inorganic mercury and methylmercury formed chelates with sodium diethyldithiocarbamate and were extracted into Triton X-114 micelles. In the second stage, a displacement reaction between sodium diethyldithiocarbamate-inorganic mercury/methylmercury and l-cysteine occurred, and the analytes entered the l-cysteine aqueous solution under ultrasonication. This aqueous solution was directly introduced to the high-performance liquid chromatography with hydride generation atomic fluorescence spectrometry and the detection was completed within 6 min. Under the optimum experimental conditions, the linear range was 0.10–5.0 μg/L (r ≥0.9993) for inorganic mercury and methylmercury, and the enhancement factors were 15.7 for inorganic mercury and 6.35 for methylmercury. The limits of detection for inorganic mercury and methylmercury were 0.004 and 0.016 μg/L, respectively. The approach was successfully applied to the determination of trace inorganic mercury and methylmercury in water and soil samples with good recoveries (85.3–110%). This method solved the problem of peak fusion of the two analytes and was successfully applied to the speciation analysis of mercury.

中文翻译：

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超声辅助双浊点提取与高效液相色谱-氢化物发生原子荧光光谱法用于环境水和土壤样品中的汞形态分析

建立了超声辅助双浊点提取后采用氢化物发生原子荧光光谱法的高效液相色谱法同时预浓缩和测定水​​和土壤样品中汞种类的方法。提取过程分为两个步骤。在第一次浊点萃取中，无机汞和甲基汞与二乙基二硫代氨基甲酸钠形成螯合物，并被萃取到 Triton X-114 胶束中。在第二阶段中，二乙基二钠-无机汞/甲基汞之间的置换反应升-半胱氨酸发生，并且分析物进入升-半胱氨酸水溶液超声处理。将该水溶液直接引入具有氢化物发生原子荧光光谱的高效液相色谱法，在6分钟内完成检测。在最佳实验条件下，线性范围为0.10～5.0 μg/L（r≥0.9993）无机汞和甲基汞，无机汞增强因子为15.7，甲基汞增强因子为6.35。无机汞和甲基汞的检测限分别为 0.004 和 0.016 μg/L。该方法已成功应用于水和土壤样品中痕量无机汞和甲基汞的测定，回收率达 85.3-110%。该方法解决了两种分析物的峰融合问题，并成功应用于汞的形态分析。