电感耦合等离子体发射光谱(ICP-OES)法测定水泥熟料中铬的干扰研究

电感耦合等离子体发射光谱法（ICP-OES）测定重金属时常面临干扰问题。为提高ICP-OES测定水泥熟料中铬的准确度，研究选取了Cr205.560、Cr267.716和Cr283.563三条谱线，根据水泥熟料中主量元素（铁、铝、钙和镁）含量，设计不同浓度单元素干扰试验，结果表明：铁对Cr283.563谱线测定有较大的正干扰，钙对三条谱线均有较大的负干扰，两者导致的相对误差（RE）均在±10%以上，其他一般为负干扰，RE在±10%以内。进一步线性回归分析发现，除铝外，其他干扰元素的干扰大小与浓度呈强线性相关性。通过多元素复合干扰试验发现干扰导致的RE约为-18%~11%，同单元素干扰加和结果比较，两者相差约为8%~10%。实际样品检测结果表明实际干扰同多元素复合干扰试验基本相同，Cr283.563谱线测定结果误差可能更小，三条谱线的实际样品加标回收率大致相当，约为80%，经回收率修正，Cr205.560和Cr267.716谱线结果满意，而Cr283.563谱线误差较大。以多元素复合干扰试验溶液作为基体，采用基体匹配法测定可基本消除干扰影响。以钙溶液作为基体的简化基体匹配法同样有效，但仅可选用Cr205.560和Cr267.716谱线。本研究从实际干扰问题出发，通过系统分析问题，找到干扰的原因，并据此提出消除干扰方法，提高了测定铬的准确度，也为检测人员解决相关干扰问题提供借鉴。

Study on the interference in the determination of chromium in cement clinker by ICP-OES

ICP-OES has been widely used in the determination of heavy metal content, while inspectors encounter interference problems frequently in the process of testing . To improve the accuracy of determination of chromium in cement clinker by ICP-OES, Cr205.560, Cr267.716 and Cr283.563 spectral lines were selected in this study. According to the main elements (Fe, Al, Ca and Mg) of cement clinker content, single element interference tests with different concentrations were carried out. The results show that: iron has a large positive interference for Cr283.563, calcium has a large negative interference for all three lines, the relative errors (RE) of them are more than ±10%, RE of the other are within ±10%, generally negative interference. Further linear regression analysis shows that there is a strong linear correlation between the interference and the concentration of interference elements except aluminum. It is found that the RE caused by interference is about -18%~11% by multi-element composite interference test, which is about 8~10% different from the sum result of single element interference. The actual sample detection results show that the actual interference is basically the same as the multi-element composite interference test. The error of the determination results of Cr283.563 spectral line may be smaller, and the recoveries of the three spectral lines are similar, about 80%. After the recovery correction, the spectral lines of Cr205.560 and Cr267.716 are satisfactory, while Cr283.563 is low. The matrix interference can be eliminated by matrix matching method with multi-element composite interference test solution as matrix. The simplified matrix matching method with calcium solution as matrix is also effective, but only Cr205.560 and Cr267.716 can be used for spectral line. In this study, the interference was systematically studied and found the reason, a method to eliminate the interference was put forward, which improved the accuracy of determination of chromium , and provided a reference to solve related problems.