矿物饲料样品磷酸钙经硝酸溶解,采用原子荧光光谱法测定其中砷和汞的含量.对影响测定的因素如仪器工作条件、溶样试剂的种类、盐酸介质的浓度、预还原剂的种类、硼氢化钾浓度、共存离子的干扰等作了研究并予以优化.荧光强度与砷和汞的质量浓度分别在100.0,5.0 μg·L-1范围以内呈线性关系,检出限(3s)依次为0.18,0.06 μg·L-1,相对标准偏差(n=11)均小于8.0%.应用此法分析3个矿物饲料,并用标准加入法测得砷和汞的回收率分别为91.7%~103.0%和91.0%~93.7%.

The sample of mineral feed,calcium orthophosphate,was dissolved with HNO3 solution,and the contents of As and Hg in the sample solution were determined by AFS.Influential factors,including working conditions of instrument,kinds of reagents for dissolving sample,concentration of HCl medium,amount of pre-reductant required,concentration of potassium borohydride,and interferences of coexisting ions,were studied and optimized.Linear relationships between the values of fluorescence intensity and mass concentration of As and Hg found were in the ranges within 100.0 and 5.0 μg·L-1,with detection limits (3s) of 0.18 and 0.06 μg·L-1,respectively.The values of RSD′s (n=11) found were all less than 8.0%.The proposed method was applied to the analysis of 3 samples of calcium orthophosphate,and test for recovery was made by standard addition method,giving values of recovery in ranges of 91.7%-103.0% (As) and 91.0%-93.7% (Hg).