Fast simultaneous determination of main components and impurity sodium ion in PAMA injection by mixed-mode chromatography.

This study describes an analytical method to control the quality of potassium aspartate and magnesium aspartate (PAMA) injection based on the simultaneous detection of the main components (K+, Mg2+ and Asp) and impurities (Na+) using a mixed-mode chromatography coupled with charged aerosol detector. To obtain optimal chromatographic separation, the effects of organic content, column temperature, buffer types, pH and concentrations were evaluated. A Response Surface Methodology (RSM) optimal design was performed after single factor experiment. The mixed-mode HPLC method is proved to be a complementary approach to the conventional ion chromatography (IC). The optimized method was successfully validated and applied to the analysis of Asp, K+, Na+ and Mg2+ in PAMA injection with good specificity, linearity, accuracy, and repeatability. The method would be useful for quality control in PAMA injection and other similar drugs, which can provide references for the analysis of drug quality by enterprises and drug regulatory department.