Detection of chloride in drinking water with mercury thiocyanate spectrophotometry

Objective:To establish the method which can be used to determine chloride with mercury thiocyanate spectrophotometry.Methods:The interaction between chloride ion and thiocyanate could release thiocyanate ion which had a chemical reaction with iron ion to generate the salmon pink ferric thiocynate,and there was a positive correlation between the color strength and the concentration of chloride ion.Hereby,we established the method to determine chloride.Results:Under the experimental conditions,the concentration of chloride was 0~300 mg/L,and there was excellent linear relationship between the concentration of chloride and the absorbance,r=0.9993.with detection wavelength at 460 nm.The recovery rate was 92%~103% and the relative standard deviation was 2.1%.Conclusion:The method is sensitive,stable,and accurate with little interference,so it is suitable for determining chloride in drinking water.