Determination of Trace Iodide,Thiocyanate and Glyphosate in Drinking Water by Capillary Ion Chromatography
A method was developed for the simultaneous determination of iodide,thiocyanate and glyphosate in drinking water by capillary ion chromatography(CIC).The sample was directly injected into CIC after filtrated by 0.22 mm nylon filter membrane,and then analyzed by IC.The analytical column was Dionex IonPac AS19(250 mm×0.4 mm) and gradient KOH was used as the eluent at a flow rate of 1.0 mL/min.The detection was performed by a suppressed conductive detector.The external standard calibration curve was used for the quantitative analysis.The linear range of the method for iodide,thiocyanate and glyphosate was 2.0-100 mg/L,the correlation coefficients were 0.9997,0.9998 and 0.9998,and the detection limits(S/N=3) were 0.3,0.2 and 0.2 mg/L,respectively.The average recoveries were 86.0%-100.6%.The method has been applied to determine trace iodide,thiocyanate and glyphosate in bottled drinking water with satisfactory results.