连续光源原子吸收光谱法测定土壤水溶性盐中钙镁

Determination of Water-soluble Ca and Mg in Soils by High-resolution Continuum Source Atomic Absorption Spectrometry

使用连续光源原子吸收光谱仪在不更换元素灯情况下,一次进样测定土壤水溶盐组成中钙、镁离子含量,测定值与标准值的相对偏差小于5%,测定速度显著提高。连续光源原子吸收光谱法可选择元素任一谱线测定,对比30个土壤样品Mg次灵敏线202 nm与主灵敏线285 nm两条谱线测定结果,两者基本一致。高浓度时Mg次灵敏线202 nm的标准曲线相关性好于主灵敏线285 nm。与传统线光源原子吸收光谱仪相比,连续光源原子吸收光谱仪测试灵敏度显著提高。

High-resolution continuum source atomic absorption spectrometer （HR-CS AAS ） without alternating hollow cathode lamp used for simultaneously quantitative determination of Ca and Mg with single sample introduction was reported in this paper. Results showed that comparing with certified values of the standard samples the relative determination deviations were less than 5% and the sample analysis efficiency was remarkably improved. Continuous radiation source provides flexibility in selection of elemental determination lines. The results from the determination of Mg in 30 soil samples showed that the accordant analytical results were obtained by using primary and secondary sensitive lines （285 nm and 202 nm respectively）, but the correlation coefficient of the calibration curve from secondary sensitive line （202 nm） is better than that from primary sensitive line （285 nm） for the samples with high Mg content. Compared with line-source atomic absorption spectrometer, sensitivity of HR-CS AAS was improved notably.