HPLC determination of the related substances in aztreonam for injection

Objective:An HPLC method for the testing of the related substances in aztreonam for injection was established.Method:The column:Agilent HC-C18column(250 mm×4.6 mm,5 μm).The mobile phase:methanol-phosphate(dipotassium hydrogen phosphate 0.8 g,dilute to 1000 mL with water,adjust its pH value to 3.0 by1 mol·L-1 phosphoric acid).The detective wavelength:254 nm.The flow rate:1.0 mL·min-1.Result:E-lsomer and open ring Aztreonam and their related sudstances could be separated completely from aztreonam for injetion.The linear range of open ring Aztreonam was 0.04-0.36 μg(r=0.9999);the average recovery was 99.2% and RSD 0.9%;the lowest limit of detection was 1.6ng.Conclusion:The method was simple,accurate and sensitive,and can be used for the determination of impurity in aztreonam for injection.