Abstract: This paper studies the commutation test con-ditions for the determination of Cl^- and SO₄^2- in valve cool-ing medium.The test determined by ion chromatography.Using the gradient elution mode to replace traditional iso-cratic elution mode, which obtain good separating effect and quantitative accuracy in chromatographic component.Test procedure is simple, in addition, it Solves the problem in measuring Cl^- and SO₄^2- in aqueous solution in the con-verter valve cooling medium in glycol.To provide a reli-able basis for quality supervision for HVDC converter valve cooling medium,which effectively controls the corrosion in internal cooling water system.

Key words: converter valve, glycol, ion Chromatogra? phy, Cl^-, SO₄^2-