DETERMINATION OF THIOCYANATE, THIOSULFATE, SULFITE AND NITRITE BY HIGH PERFORMANCE LIQUID CHROMATOGRAPHY COUPLED WITH ELECTROCHEMICAL DETECTION

Abstract

High performance liquid chromatography with an electrochemical detector (Yanaco Model VMD-101) was used to determine SCN^-, S₂O₃^2-, SO₃^2- and NO₂^-. Those anions were separated on a TSK-GEL IEX-520 QAE (anion exchanger) column, with a mobile phase of 0.05 M sodium phosphate buffer (pH 7.5) containing 0.05 M NaNO₃ and were detected electrochemically at 0.9 V vs. Ag/AgCl. The minimum detectable amounts of SCN^-, S₂O₃^2-, SO₃^2- and NO₂^- were 0.015, 0.05, 2.5, 0.012 ppm, respectively.