Determination of Organic Acids in Sheng-mai Injection by Ion Exclusion Chromatography
A method was developed for the separation and determination of three organic acid,viz citric acid,malic acid and succinic acid in Sheng-mai Injection by ion exclusion chromatography with suppressed conductivity detection.The chromatographic separation was performed on a Transgenomic Sep-ION-300 column(300 mm length ×7.8 mm i.d.,8 μm) at 70 ℃ and eluted with a mixture of 5 mmol/L sulphuric acid and acetone(95 ∶ 5) at the flow rate of 0.4 mL/min.The effects of the concentration of sulphuric acid,the volume ratio of acetone and column temperature were investigated and optimized.The calibration curve for citric acid,malic acid and succinic acid was in a good linearity in the range of 7.45-476.5 mg/L,14-521.0 mg/L and 3.47-222.0 mg/L,respectively.The average recovery for citric acid,malic acid and succinic acid was 97.12% with RSD 2.7%,96.9% with RSD 2.3%,and 95.09% with RSD 1.9%,respectively.The validated method was successfully applied to determination of organic acids in 15 batches of Sheng-mai Injection.