一种基于常压消解仪同时测定烟用有机肥中总氮、总磷、总钾含量的样品前处理方法

A sample pretreatment method for simultaneous determination of total nitrogen,total phosphorus and total potassium in organic fertilizer for tobacco based on atmospheric digestion instrument

采用正交表头L16(4^3×2^6)设计正交实验,优化了一种适用于同时测定烟用有机肥中总氮、总磷、总钾含量的样品消解仪方法。实验考察了三个因子:称样量、冲洗水体积、硫酸体积,每个因子各四水平的实验条件。经过直观分析发现:称样量对钾的测定结果影响较大,故取钾测定时消化条件中称样量的最佳条件,即0.4 g,而冲洗水体积和H2SO4体积对总氮、总磷、钾测定结果的影响都不大。本着尽量淹没样品、节约试剂的原则,冲洗水和H2SO4的体积均选择4 m L。

In this paper,the orthogonal head L16(4^3×2^6)was used to optimize a digester method for simultaneous determination of total nitrogen,total phosphorus and total potassium in organic fertilizer for tobacco.The experimental conditions of three factors:sample weight,volume of flushing water and volume of sulfuric acid were investigated.After intuitive analysis,it was found that:the sample weight has a great influence on the determination results of potassium,so the best condition of weighing sample volume in digestion conditions is 0.4 g,while the volume of flushing water and H2SO4 has little influence on the determination results of total nitrogen,total phosphorus and potassium.In the principle of submerging the sample as much as possible and saving reagents,the volume of flushing water and H2 SO4 are selected as 4 m L.