Determination of organic anions in waste liquid of sodium hydrosulfite production by ion chromatography

An ion chromatographic method for simultaneous determination of formate, hy droxyethyl sulfonate (HES), hydroxyethyl thiosulfate (HET), and coexisting anions in the industrial waste liquid of sodium hydrosulfite production was developed. The mixture of 1 .6 mmol/l of phthalic acid and 1.2 mmol/l tri- (hydroxyethyl) aminomethane was used as eluent. The interference of coexist ing sulfite anion with HES was avoided by selective oxidation with hydrogen peroxide as oxidizer. The other coexisting inorganic anions, Cl-, SO42- an d S2O32- can be determined simultaneously. The linear range of the peak are a calibration curves for all analytes was up to two or three orders of magn itude. The detection limits (S/N=3) for formate, HES and HET were 2.4, 1.0 and 0.5 mg/l., respectively. The recoveries for all analytes were 91.61-100 .6%. (C) 1999 Elsevier Science B.V. All rights reserved.