土壤中阳离子交换量分析方法的优化研究

Analysis Methods for Cation Exchange Capacity in Soil: Optimization

为了提高土壤中阳离子交换量的检测效率,针对现用标准方法的不足,介绍了一种利用阳离子交换量前处理系统并结合全自动凯氏定氮仪测定土壤中阳离子交换量的快速方法,对离心和蒸馏滴定分析步骤进行了优化改进。在原理不变的前提下,对实验仪器的参数进行了最佳选择。实验得出:乙酸铵搅拌15 min,乙醇淋洗4次,蒸馏5 min。该条件下,通过对国家土壤有证标准物质进行测试,得出分析方法的精密度和准确度均符合要求。本研究的分析方法操作简便、效率高、准确度和重复性良好,适用于大批量土壤中阳离子交换量的测定。

To improve the detection efficiency of the cation exchange capacity in soil,in view of the deficiency of the present standard,this study puts forward a rapid detection method by combining the pretreatment system of cation exchange capacity and Kjeltec Automatic Azotometer.The analytical steps of centrifugal and distillation titration were optimized and improved.On the premise of constant principle,the parameters of the instrument were optimized.The results were as follows:ammonium acetate was stirred for 15 min;ethanol was used to wash the soil for 4 times,and distilled for 5 min.Under the condition,the precision and accuracy of this analysis method were in accordance with the requirements by testing the national soil certified reference materials.Thus the analysis method is simple,efficient,accurate and reproducible.It is suitable for the determination of the cation exchange capacity in large quantities of soil samples.