ABSTRACT
Objective:To establish a method of ion chromatography for the determination of sodium, potassium and citric acid in potassium sodium hydrogen citrate granule. Methods:The chromatographic conditions for potassium and sodium were as follows:a Di-onex IonPac CS12A column (250 mm × 4. 6 mm, 5μm), 0. 02 mol·L-1 methane sulfonic acid solution as the mobile phase, the flow rate of 1. 0 ml·min-1 , the suppressor of CSRS 300, the inhibition current of 59 mA, the inhibition type conductivity detector, and the injection volume of 25 μl. The chromatographic conditions for citrate were as follows: a Dionex HPICE-AS1 colunm ( 250 mm × 9. 0 mm,7. 5 μm), 0. 015 mol·L-1sulfuric acid solution as the mobile phase, the flow rate of 0. 6 ml·min-1, the detection wave-length of 220 nm and the injection volume of 10 μl. Results: The linear range of sodium was 0.82-82.49 μg·ml-1(r=0.9999), and the average recovery was 98.9%(RSD =0.55%, n =9). The linear range of potassium was 1.38-137.89 μg·ml-1 (r =1. 0000), and the average recovery was 100. 5% (RSD=0. 53%, n=9). The linear range of citric acid was 0. 021-10. 600 μg· ml-1(r=1. 0000), and the average recovery was 99. 1% (RSD=0. 54%, n=9). Conclusion:The method is simple, rapid and ac-curate, and can be used for the quality control of potassium sodium hydrogen citrate granule.