连续光源原子吸收光谱法测定土壤中的有效硫含量

Determination of Available Sulfur in Soil by Continuum-source Atomic Absorption Spectrometry

[目的]为了建立连续光源原子吸收光谱法测定土壤中有效硫的方法。[方法]采用连续光源原子吸收光谱法,在富燃乙炔-空气火焰条件下,通过测定CS双原子分子吸收,确定土壤提取液中有效硫的含量,研究优化试验条件。[结果]在CS 258.056 nm时测定硫元素的检出限为3.97 mg/L,定量限为14.8 mg/L,CS分子吸收具有较宽的线性范围,方法在试验浓度范围（0-500 mg/L）内获得良好的线性。对土壤标准物质中有效硫元素含量的测定结果均在其不确定度范围内。[结论]连续光源原子吸收光谱法是一种测定土壤中有效硫元素含量的简便、快速、准确的方法。

[Objective] The research aimed to establish a method for the determination of available sulfur in soil. [Method]The concentration of available sulfur in soil was determined by continuum-source atomic absorption spectrometry based on the absorption of CS diatomic molecule formed in fuel-rich air and ethyne flame. The instrumental conditions were optimized. [Result] The detection limit of sulfur was 3. 97 mg / L,and the limit of quantification was 14. 8 mg / L in CS 258. 056 nm. CS molecular absorption has a wide linear range. This method had good linearity within the tested concentration scope（ 0- 500 mg / L）. The concentration of available sulfur in certified soil reference material was determined,and the results met the required accuracy and precision. [Conclusion]Continuum-source atomic absorption spectrometry was proved to be an easy,rapid and accurate method for available sulfur determination in soil.