Method for Improving the Determination of Dibromoacetic Acid in Cefathiamidine

[Objectives]To establish an LC-MS method for the determination of dibromoacetic acid in Cefathiamidine and Cefathiamidine for Injection.[Methods]Shiseido PC HILIC column(2.0 mm ×100 mm,3μ.m)was used.The mobile phase was 0.005 Mammonium formate and the mobile phase was acetonitrile with gradient elution.The flow rate was 0.3-0.8mL/min.[Results]The limit of detection was 0.2500 ng/mL and the limit of quantification was 0.500 ng/mL,which were 2.5%and 5.0%of the impurity limits,respectively.The recov-ery rate was 103.85%.[Conclusions]This method improved the detection of dibromoacetic acid impurities in Cefathiamidine,and has that advantage of good specificity,low limit of detection and limit of quantification,high sensitivity,high accuracy,interference resistance,can meet the detection requirements of Cefathiamidine,and is suitable for the quality control of Cefathiamidine.

Analysis of Polymer Impurities in Cephalosporin Antibiotics

[Objectives]To establish a HPLC-MS method for the determination of polymer impurities in cefathiamidine and its preparations.[Methods]Kromasil 100-5 C_(18) column(4.6 mm ×250 mm,5μm)was used for analysis;mobile phase ammonium acetate solution(pH 6.30)-acetonitrile,gradient elution;volumetric flow rate 1.0 mL/min;column temperature 40℃;multi-reaction monitoring mode was used for analysis,and positive ion scanning was chosen as the electrospray ion source.[Results]The resolution between impurities and main peaks under this method was greater than 1.5,and 8 known impurities and 2 polymer impurities could be completely separated and distinguish-ed.It was inferred that the molecular ion peak[M+H]^(+):m/z727.1874,m/z 785.1937 was the possible polymer impurity of this product.[Conclusions]A method for the analysis of polymer impurities in cefathiamidine and its preparations was formed,which could achieve the purpose of simultaneous analysis of small molecule impurities and polymer impurities,and could better control the content of single impurities in the polymer,providing a reliable inspection basis for strict control of cefathiamidine quality.