LC/MS Determination of Ceftriaxone Sodium Related Substances

Objective: To develop a capillary electrophoresis method for determination of related substances in ceftriaxone sodium. Methods:The uncoated fused-silica capillary (50 cm×75μm) was used. The running buffer composed of 40 mmol·L~(-1) phosphate buffer containing 100 mmol·L~(-1) sodium dodecylsulphate. The separation voltage was 12 kV (40-50 μA) and the capillary temperature was 25℃. The detection wavelength was 254 nm. The sample was solved in water with a concentration of 5 mg·mL~(-1) and 0. 1 mg·mL~(-1) respectively for impurity determination and content assay,and was injected to the column by pressure(3. 447 kPa) for 4 s. Results:Twenty-one impurities in ceftriaxone sodium could be detected. Ceftriaxone sodium and the degradations obtained by acid hydrolysis, alkaline hydrolysis and oxidation could be separated well. The calibration curve of ceftriaxone sodium was linear in the range of 0.0125-0.4 mg·mL~(-1). The limit of detection and limit of quantitation were 5.2 μg·mL~(-1) and 12. 5 μg·mL~(-1) respectively. The number of impurities detected by CE was more than that by HPLC,however the biggest impurity content determined by CE was the same as that by HPLC. The values of intra-day and interday RSD of migration time of impurities were less than 0. 94% and 1. 15% respectively. The values of intra-day and inter-day RSD of peak area were less than 17.0% and 26. 8% respectively. The lower impurity content was, the bigger the RSD was. Conclusions: The HPCE method developed was accurate, and could be complement to HPLC for determination of the impurity and help pharmaceutical manufacturer to analysis the possible source of the impurity.