氢化物发生-原子荧光光谱法测定羊剪绒鞋中汞和砷含量
HG-AFS Determination of Mercury and Arsenic in Sheepskin Shoes
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摘要: 羊剪绒鞋样品采用人工汗液萃取(40 ℃,20 min)和硝酸微波消解两种前处理方法进行处理,所得试样溶液以20 g·L-1硼氢化钾溶液为还原剂,盐酸(5+95)溶液为载流,用氢化物发生-原子荧光光谱法测定其中汞和砷的含量。试验结果表明:两种前处理方法所得精密度和回收率都较好。汞和砷的质量浓度分别在一定的范围内与其荧光强度呈线性关系,方法1#所得汞和砷的检出限(3S/N)分别为0.001 0,0.005 7 μg·L-1,方法2#所得汞和砷的检出限(3S/N)分别为0.000 8,0.005 3 μg·L-1。用两种方法测定了羊剪绒鞋样品中汞和砷的含量,并用标准加入法做回收试验,测得回收率分别在93.5%~99.2%和91.9%~102%之间,测定值的相对标准偏差(n=5)分别在1.1%~4.3%和1.0%~4.5%之间。Abstract: Samples of sheepskin shoes were treated by extraction with artificial sweat (method 1#) and microwave digestion with HNO3 (method 1#) separately, and the contents of Hg and As in the sample solutions were determined by HG-AFS with 20 g·L-1 KBH4 as reducing reagent and HCl (5+95) solution as carrying solution. It was found that precision and recovery of the method obtained by the two pretreatment methods were all satisfactory. Linear relationships between values of absorbance and mass concentration of Hg and As were kept in definite ranges, with detection limits (3S/N) of 0.001 0 and 0.005 7 μg·L-1 (method 1#) and 0.000 8 and 0.005 3 μg·L-1 (method 2#)) respectively. The proposed method was applied to the analysis of sample of sheepskin shoes and recovery was tested by standard addition method values of recovery found were in ranges of 93.5%-99.2% for Hg and 91.9%-102% for As. Values of RSD′s (n=5) were found in ranges of 1.1%-4.3% for Hg and 1.0%-4.5% for As.