Determination of Related Impurities in Contrast Agent Iopromide by High Performance Liquid Chromatography

A method for the determination of five impurities in iopromide, a non-ionic contract agent, was proposed by high performance liquid chromatography. Eclipse C₁₈ Plus chromatographic column was used as the separation column, and the mixed solution of water-acetonitrile-2-butanol with a volume ratio of 55:40:5 and water with various volume ratios was used as the mobile phase for gradient elution. Five impurities in 5.0 g·L^-1 sample solution were determined at the detection wavelength of 245 nm. As found by results that linerity ranges of standard curves were kept in the ranges of 2.57-51.4 mg·L^-1, 5.05-101 mg·L^-1, 2.56-51.2 mg·L^-1, 1.01-20.2 mg·L^-1, 0.51-10.2 mg·L^-1, respectively, with detection limits (3S/N) of 0.10, 0.20, 0.15, 0.12, 0.10 mg·L^-1, respectively. Spiked recovery tests were made on the actual sample at three concentration levels, giving recoveries of impurities of 1-5 were 105%, 93.7%, 95.2%, 97.8%, 112%, respectively. Results of tests for repeatability and intermediate precision showed that RSDs (n=6) of measured values of impurities of 1-5 were all less than 15%.