火焰原子吸收法测定微生物肥料中总钾含量的研究

Study on determining the contents of total potassium for microbial fertilizers by flame atomic absorption spectrometer

通过对样品消解、原子吸收仪器参数设置、对多个钾含量差异较大的复合生物肥料样品钾含量（1.1%-18.2%）测试、回归方程的比较,以及与重量法结果比对,建立了适应复合微生物肥料特点的总钾含量火焰原子吸收测试方法。结果表明,硫酸-双氧水消解体系可以取得良好的消解效果,且0.5 g取样量完全满足微生物肥料的钾含量实际测定需要;采用二次回归和直线回归建立回归方程进行测试,其结果都接近实际值,满足测试要求,二次回归测试结果更接近标准值,因此二次回归可作为测试的首选;建立的测定方法在准确度、检测限、与现有方法的比对等多方面都满足相关国家标准要求,且操作简便,对钾含量浓度1.1%-21.7%的微生物肥料样品钾含量测定具有良好的适用性,可以应用于微生物肥料的钾含量定量检测。

The testing method by flame atomic absorption spectrometer （FAAS） for determining the contents of total potassium for compound microbial fertilizers （CMF） was established by optimizing the method of dissolving samples, instrument parameters, comparison of regression models as well as the recovery rates of K contents with national-benchmark-matter and CMF which representing the samples of different K content （ 1.1% - 18.2% ）. The results showed that, The sulfuric acid- hydrogen peroxidel mixer could completely dissolve the CMF samples and the 1. 5 g sample could satisfy the test correctly. The quadratic regression equation was better than linear regression equation with higher precision although both of the regression equations could obtain acceptable test results. The newly established testing method was suitable for the determining the total potassium content for CMF samples whose potassium content ranged from 1.1% to 21.7% with good accuracy, recovery rate and error permission, additionally the sensitivity of the method is also high enough for the test.