应用微分电位滴定仪测定盐渍土中氯离子的初步研究

在盐渍化土壤中,阴离子氯具有高度的迁移性,土壤水盐运动的状况常借氯离子动态变化来指示,此外,氯离子对植物的危害,也比其他阴离子显著.因此,氯离子的测定,不论在理论研究上或在生产实践中都有一定的意义.盐渍土中含氯量的测定,一般用容量滴定法(莫尔法),但因其终点显示是用目测指示剂的颜色变化来决定,待测标本如果混浊或有色,就会给测定带来一定困难.

PRELIMINARY STUDY ON THE APPLICATION OF AN AUTOMATIC DIFFERENTIAL POTENTIOMETRIC TITRATOR FOR THE DETERMINATION OF CHLORIDE IN SALTAFFECTED SOILS

The chloride content in various salt-affected soils in Jiangsu,Xinjiang,Henan and Gansu provinces are determined by three methods,which are the automatic differential potentiometric titration,Mohr method and anticipated end point potentiometric titration.The advantages of the application of an automatic differential potentiometric titrator for the determination of chloride in salt-affected soils are as follows:1.The result of determination is not affected by the change in Eo' of electrode,slope of the titration curve and the variation in ionic strength of soil solution.2.The method is rapid and accurate.It is not necessary to anticipate and check the end point potential.The results of determination have good reproducibility.3.This instrument can also be used in other fields,such as complexometric titration,oxidation-reduction titration,acid-base titration etc.