0.500 0 g金属铬样品用盐酸10 mL,过氧化氢1 mL溶解,加入高氯酸1 mL蒸至冒烟,使铬(Ⅲ)氧化至铬(Ⅵ),加水稀释并在乙酸缓冲介质中加入100 g·L-1乙酸铅溶液9.0 mL沉淀分离铬,滤液用水定容至100 mL作为试液。采用电感耦合等离子体原子发射光谱法测定其中铜、镍、铁、锰、铝和镁等6种杂质元素。所选择此6种元素的分析谱线依次为327.393,231.604,238.204,257.610,396.153,285.213 nm。6种元素的质量浓度均在10.00 mg·L-1以内与其发射强度呈线性关系,方法的检出限(3s)在0.001 8~0.020 mg·L-1之间。方法应用于实样分析,测定值与基体匹配法测定结果相符,测定值的相对标准偏差(n=6)在0.87%~2.9%之间。用标准加入法测定了方法的回收率,测得回收率在93.2%~113%之间。

The sample (0.500 0 g) was dissolved with HCl (10 mL) and H2O2 (1 mL). The solution was fumed with 1 mL of HClO4 to oxidize Cr(Ⅲ) to Cr(Ⅵ). After diluting with water, and in an HOAc buffer medium, 9.0 mL of 100 g·L-1 lead acetate solution was added to precipite matrix chromium and the filtrate was diluted to 100 mL with water. Six impurity elements, i.e. Cu, Ni, Fe, Mn, Al and Mg in the solution were determined by ICP-AES at their analytical spectral lines of 327.393 nm, 231.604 nm, 238.204 nm, 257.610 nm, 396.153 nm and 285.213 nm respectively. Linear relationships between values of emission intensity and mass concentration of the 6 elements were kept in the same range within 10.00 mg·L-1, with detection limits (3s) in the range of 0.001 8-0.020 mg·L-1. The proposed method was applied to the analysis of substantial sample, giving results in consistency with the values obtained by matrix matching method. Values of RSD′s (n=6) found were in the range of 0.87%-2.9%. Test for recovery was performed by standard addition method, giving values of recovery in the range of 93.2%-113%.