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An ion chromatographic (IC) method was developed for the determination of maleic acid (anhydride) in starch.Maleic acid belongs to the resin adhesive chemical raw materials,mainly used in industrial adhesive.1f added in the food,maleic acid can increase the elasticity and shelf life,but that was harmful to the human body.Starch was at high risk of being added maleic acid (anhydride).Maleic anhydride was hydrolyzed into maleic acid quickly in water,so we can get the amount of maleic acid (anhydride) by detecting the content of maleic acid in the sample.As an organic acid,maleic acid dissolved in water and was in the status of anion,and ion chromatography became the preferred method for determination of maleic acid.The sample was extracted by water in ultrasonic for 20 minutes,filtrated by DIONEX OnGuard Ⅱ RP column and 0.22μm membrane,and then injected to the IC system directly.4.5mmol/L Na2CO3-1.4mmol/L NaHCO3 was used as the eluent at a flow rate of 1.0mL/min.The analytical column was DIONEX lonPac AS22(4×250mm),the detection was performed by a Dionex DS6 conductive detector.The quantitive analysis of external standard calibration curves was used.The linear range of the method for maleic acid was 0.5~100.0 mg/L (r=0.9998).The average recoveries were 91.3~94.6% with the relative standard deviations(RSD) less than l.4%.The detection limits(S/N=3) was 0.08 mg/L for maleic acid,that was 0.83mg/Kg eauivalent in the real samples.The method has been used to determine the maleic acid (anhydride) in starch samples with satisfactory results.