双电解池正反馈示波计时电位滴定法测定土壤中钾含量

Determination of Soil Potassium by the Method of Electrometric titration with Double Electrolysis Pools Positive-negative Feedbake Oscillegraph

采用四苯硼钠为滴定剂 ,双电解池正反馈示波计时电位法确定终点测定土壤中钾含量 ,滴定在 p H大于 7的 Na OH- Na Ac碱性底液中进行 ,将溶液加热煮沸后 ,铵离子没有干扰。本方法测定的回收率在 99.5%～ 10 0 .5% ,准确度与火焰光度法接近 ,装置简单 ,操作简便 ,测量条件易于控制 。

In this papter ,TPB is used as titration agent,potassium in soil was determined by means of double cell positive feedbake oscillographic chronopotentio\|titration in NaoH\|NaAc solution(pH>7).The recovery rate of method is between in 99.5%~100.5% and accuracy is same as flame spectrophotometry.It's apparatus and apperation are simply,the measurement condition is easy to control.It can be used to determine potassium in soil.