Determination of Chloride in Drinking Water by Chloride Ion-Selective Electrode / 环境与健康杂志

ABSTRACT

Objective To establish a simple,rapid,accurate and practical method for determination of chloride in drinking water by chloride ion-selective electrode.Methods The chlorine ion-selective electrode was used as indicator electrode and type217saturated calomel electrode of the double salt bridge(the lower salt bridge was filled with a solution of0.1mol/L potassium nitrate)was used as reference electrode.The contents of chloride in water were calculated using the calibration curve method in the electrolyte containing0.1mol/L potassium nitrate.Results The linear range of the method was10 -5 -10 0 mol/L and the best lin ear range was10 -4 -10 -1 mol/L with r=0.9999and the slope=53.5?0.667.The detection limit,recovery rate and coefficient of variation(CV)were0.3545mg /L,94.2%-102.2%(mean98.1%)and2.8%respectively.The suitable pH for the determination of the method was2-10.In the solution containing3.545mg/L chloride,50times more BrO -3 ,NO -2 ,CH 3 COO - ,SO 42- ,F - ,CrO 42- and10times more CO 32- could not interfere with the detection,but Br - and I - were interfering factors.The re-sults obtained by the chlorine ion-selective electrode method and the national standard determination method showed no statistic differences.Conclusion The method was easy to operate,rapid,accurate and suitable for determination of chloride in water.