Determination of amoxicillin,cefaclor and cefixime Residues in dihydroartemisinin and piperaquine Phosphate tablets by LC-MS

OBJECTIVE To establish an LC-MS/MS method for the determination of amoxicillin,cefaclor and cefixime residues in dihydroartemisinin and piperaquine phosphate tablets.METHODS The column was Thermo Gold C₁₈(2.1 mm×50 mm,1.9 mm),mobile phase was 10 mmol·L^-1 ammonium acetate solution (A)-acetonitrile (B).The diluent of amoxicillin and cefaclor was 10 mmol·L^-1 ammonium acetate solution (adjust the pH value to 7.2 with ammonia),the flow rate was 0.3 mL·min^-1,and the injection volume was 10 mL.The diluent of Cefixime was 10 mmol·L^-1 ammonium acetate solution (adjust the pH value to 11.0 with ammonia),the flow rate was 0.25 mL·min^-1,injection volume was 2 mL.Amoxicillin,cefaclor and cefixime were eluted by 2 gradient conditions respectively.RESULTS The linearity of the method was good,the linear equations were y=3 734.53x-2 188.63(r=0.999 5)(amoxicillin),y=1 396.67x-266.554(r=0.999 8)(cefaclor),y=3 636.39x+2 277.48(r=0.999 7)(cefixime).The repeatability RSDs of amoxicillin,cefaclor and cefacoxime were 3.1%,2.8%,2.2%,respectively.The recovery rates of the three antibiotics were 107.1%,97.0%,105.8%,RSDs were 4.3%,2.9%,4.4%,respectively.The detection limit was 2 ng·mL^-1.CONCLUSION The established method for the determination of amoxicillin,cefaclor and cefixime in dihydroartemisinin and piperaquine phosphate tablets by LC-MS is rapid,sensitive and reproducible,which can be used for the determination of the three components.