电感耦合等离子体质谱法测定土壤/沉积物中16种重金属的研究

目的]采用Carius管密封溶样技术,建立了王水消解—电感耦合等离子体质谱(ICP-MS)直接测定土壤/沉积物中16种重金属元素的分析方法。方法]190℃下王水消解样品,稀释后即可直接测定。结果]ICP-MS测定时,乙醇不仅对As、Se的检测信号有较明显的增敏作用,而且对复合离子40Ar35Cl+、35Cl16O+、37Cl16O+的形成有一定的抑制作用。结论]该方法应用于一系列土壤和水系沉积物国家标准物质,所得结果与推荐值相吻合,方法精度优于5%,方法检出限(3σ,DF=1000)为0.001 mg/kg(Cd)～0.774 mg/kg(Cr)。

Determination of 16 Heavy Metals in Soils/Sediments by Inductively Coupled Plasma Mass Spectrometry

Objective] A method had been developed for the determination of sixteen kinds of heavy metals in soils/sediments by inductively coupled plasma mass spectrometry.Method] Using the Carius tube technique,the samples were digested using aqua regia at 190 ℃,and the content of the heavy metal could be determined after direct dilution of the supernatant.Result] The effects of ethanol on analyte sensitivity was evaluated and the optimal effect was obtained using ethanol,making the intensity of As and Se increase.In addition,ethanol could play some function in suppression of the formation of the polyatomic 40Ar35Cl+,35Cl16O+ and 37Cl16O+.Conclusion] The method was applied to a series of certified reference materials and the analytical results were consistent with their certified values.The precision for this method was better than 5%.The limits of detection(3σ criteria) for this method were evaluated and they were obtained within the range of 0.001 μg/g(Cd) to 0.774 mg/kg(Cr).