电感耦合等离子体原子发射光谱法测定高纯铁中痕量磷

在0.57～1.43 mol/L硝酸介质中, 用甲基异丁基酮(MIBK)萃取钼酸铵与磷生成的磷钼杂多酸, 使磷与基体铁分离后, 选择波长213.618 nm的谱线作为分析线, 采用电感耦合等离子体原子发射光谱法(ICP-AES)测定了高纯铁中磷的含量。校准曲线的线性回归方程为I= 15.04ρ+0.012 1, 相关系数为0.999 6, 方法的检出限为0.020 mg/L。通过萃取分离和选择合适的谱线作为磷的分析线, 基体和共存元素对测定没有干扰。方法用于多个高纯铁标准物质中磷的测定, 测定值与认定值一致, 测定结果的相对标准偏差(n=10)在0.54%～2.9%之间。方法适用于高纯铁中0.000 10%～0.010%磷的测定。

Determination of trace phosphorus in high purity iron by inductively coupled plasma emission spectrometry

After ammonium phosphate was extracted with methyl isobutyl ketone (MIBK) to form phosphomolybdic heteropoly acid with phosphorus in 0.57-1.43 mol/L nitric acid medium, phosphorus could be separated with iron substrate. Thus, a method for determination of phosphorus in high purity iron was established by inductively coupled plasma atomic emission spectrometry (ICP-AES) with 213.618 nm as the analytical line. The linear regression equation of the calibration curve was I = 15.04ρ +0.012 1 with the correlation coefficient of 0.999 6, and the detection limit was 0.020 mg/L. With extraction separation and the suitable spectral lines as the analytical line for phosphorus, there was no interference from the matrix and the coexisting elements with the determination. The system was applied to the determination of phosphorus in multiple certified reference materials of high purity iron, the results were consistent with the certified values and the relative standard deviations (n=10) were in the range of 0.54%-2.9%. The method was applicable to the determination of phosphorus in the range of 0.000 10%-0.010 % in high purity iron.