Abstract: A method for simultaneous determination of four kinds of phosphate by ion chromatography in detergent product was established.The detergent sample was dissolved in water for injection.NaOH solution was used as gradient elution agent and the anions were separated by AS11-HC column (250 mm×4 mm).Content of the four kinds of phosphate were quantified by conductivity detector.The peak area vs. mass concentration exhibits linearity in the range of 5.0-100.0 mg·L^-1.The lowest limits of detection of phosphate,pyrophosphate,tripolyphosphate and trimetaphosphate are 0.2,0.5,0.5 and 0.1 g·kg^-1 respectively.The spiked recoveries are in the range of 96.20%-103.40%.The relative standard deviations are 1.98%-3.81%.

Key words: detergent, phosphate, ion chromatography