密闭酸溶-电感耦合等离子体质谱法测定道路扬尘中铜铅锌镉铬镍砷

准确测定道路扬尘样品中重金属元素Cu、Pb、Zn、Cd、Cr、Ni、As,对于城市道路环境污染的防治工作来说意义重大.采用HF-HNO3体系密闭酸溶法消解样品,选择52Cr、60Ni、63Cu、66Zn、75As、111Cd、208Pb为测量同位素,采用He气模式的碰撞反应池技术测定Cr和As,采用仪器自带干扰校正公式...

Determination of copper,lead, zinc,cadmium, chromium,nickel and arsenic in road dust by inductively coupled plasma mass spectrometry with acid digestion in closed system

The accurate determination of heavy metals (Cu, Pb, Zn, Cd, Cr, Ni and As) in road dust samples is of great significance for the prevention and control of environmental pollution in urban roads. The samples were digested by acid dissolution in closed system in HF-HNO₃ system. ⁵²Cr, ⁶⁰Ni, ⁶³Cu, ⁶⁶Zn, ⁷⁵As, ¹¹¹Cd and ²⁰⁸Pb were selected as the measuring isotopes. The contents of Cr and As were determined by collision reaction cell technique using mode of He. The determination results of Cd were corrected by the interference correction equation equipped in the instrument. Consequently, the determination method of Cu, Pb, Zn, Cd, Cr, Ni and As in road dust samples by inductively coupled plasma mass spectrometry (ICP-MS) was established. The sample dissolution conditions were optimized. The results showed that 0.1 g of sample could be fully dissolved by 7.0 mL of mixed acid (HF∶HNO₃=1∶6, volume ratio) after digestion in closed system at 160 ℃ for 2 h. Under the optimized experimental conditions, the correlation coefficient of the calibration curve was higher than 0.999. The limit of detection ranged from 0.012 to 0.096 μg/g, and the limit of quantification was between 0.040 μg/g and 0.32 μg/g. The proposed method was applied to the determination of Cu, Pb, Zn, Cd, Cr, Ni and As in road dust samples. Moreover, the spiked recovery tests were also conducted. The relative standard deviations (RSD, n=12) of determination results were all less than 4%, and the spiked recoveries were between 95% and 104%. The road dust samples were analyzed according to the experimental method. The measurement results were basically consistent with those obtained by high-pressure microwave digestion-ICP-MS for Cu, Pb, Zn, Cd, Cr and Ni, and hydride generation atomic fluorescence spectrometry (HG-AFS) for As.