Study on the determination of chloride ions by hydrogen peroxide pretreatment and silver nitrate titration
The determination of chloride ions(Cl-)plays a crucial role in studying chloride nutrition and salt stress processes.However,the sample preparation remains a challenge in detecting Cl-,and there is no unified method for plant,soil,fertilizer and water samples.Based on the mechanism of silver nitrate(AgNO3)titration for Cl-determination,the mechanism and method of using hydrogen peroxide(H2O2)for sample pretreatment was investigated.The results showed that H2O2,in a non-concentrated acid environment,could not oxidize Cl-to chlorine gas(Cl2).The hydrogen ions(H+)produced from the ionization of H2O2 could combine with Cl-to form hydrogen chloride(HC1),which volatilized under heating conditions,leading to loss of Cl-.The sample could be pretreated using H2O2 under heating reflux and condensation conditions,which not only prevented loss of Cl-but also facilitated subsequent determination of titration end point.The H2O2 pretreatment method was suitable for determination of Cl-in plants,soil and turbid water samples.This method had the advantages of simple operation,no secondary pollution,high accuracy and precision of measurement results.This study established a theoretical and practical foundation for developing a unified standard testing method for Cl-in different matrix samples.
万方数据
维普
