Determination of phosphate in wheat flour products by microwave digestion-ion chromatography

Phosphate in wheat flour products,which was pretreated by microwave digestion technique,was determined by ion chromatography equipped with a conductivity detector.The chromatographic column was IonPac AS19(4×250 mm)and the mobile phase was 35 mmol/L KOH solution at a flow rate of1.0 mL/min.The result showed that the recovery rate for this method was 97.0%~115.0%and the relative standard deviation was less than 0.5%.The linear regression coefficientwas higher than 0.999 within the concentration range of 1.0~50.0 mg/L.As a simple and rapid testing,this method showed satisfied accuracy and was suitable for the determination of phosphate in wheat flour products.