地下水中无机砷的高效液相色谱-氢化物发生-原子荧光测定法

目的 建立地下水中无机砷(iAs~(3+)、iAs~(5+))的高效液相色谱.氢化物发生-原子荧光(HPLC-HG-AFs)测定法.方法 以磷酸氢二铵为流动相,在Hamilton PRP-X100阴离子交换柱上有效分离出水中iAs~(3+)和iAs~(5+),通过氢化物发生-原子荧光光谱仪测定iAs~(3+)和iA5+的含量.结果 在2～150μg/L线性范围内,iAs~(3+)的线性回归方程为y=159 280x-9515.9,r=0.9998,检出限为0.22μg/L;iAs~(5+)的线性回归方程为y=78 901x+53 737,r=0.999 2,检出限为0.75 μg/L.该方法所得iAs~(3+)的平均回收率为100.49%～102.05%,RSD为1.59%～3.69%;iAs~(3+)的平均回收率为99.08%～101.06%,RSD为1.83%～4.12%.该方法和氢化物发生.冷阱捕获.原子吸收法(HG-cold trap-AAS)测定地下水无机砷含量的结果比较,差异无统计学意义(P>0.05).结论 该方法线性范围宽、精密度高、稳定性好,适用于地下水样品中无机砷的测定.

Determination of Inorganic Arsenic in Groundwater by High Performance Liquid Chromatography-Hydride Generation Atomic Fluorescence Spectrometry

Objective To develop a method for the determination of inorganic arsenic species iAs~(3+) and iAs~(5+) in groundwater with high performance liquid chromatography-hydride generation-atomic fluorescence spectrometry (HPLC-HG-AFS). Methods Diammonium phosphate was used as mobile phase. iAs~(3+) and iAs~(5+) were separated effectively in a PRP-X100 anion exchange column, then they were detected with HG-AFS. Results The results showed that in the range of 2-150 μg/L, the linear equation for iAs~(3+) was y=159 280χ-9 515.9(r=0.999 8), for iAs~(5+) was y=78 901x+53 737 (r=0.999 2). The detection limit of iAs~(3+) and iAs~(5+) were 0.22 ug/L and 0.75 μg/L. respectively. For iAs~(3+), the average recovery rates were 100.49%-102.05% and RSD was the range of 1.59%-3.69%. For iAs~(5+), the average recovery rates were 99.08%-101.06% and RSD was in the range of 1.83%-4.12%. The results were consistent with those by hydride generation-cold trap-atomic absorption spectrometry (HG-cold trap-AAS) (P>0.05). Conclusion This method is sensitive, accurate, stabile and is applicable to the determination of inorganic arsenic in groundwater samples.