Determination of methionine sulfoxide in compound amino acid injection by HPLC-FLD with pre-column derivatization
Objective To establish an HPLC-FLD method for the determination of methionine sulfoxide in compound amino acid injection.Methods Pre-column derivatization HPLC-FLD was performed on the Agilent Poroshell 120 EC-C18 column(3.0 mm×100 mm,2.7 μm),using the gradient elution program comprising mobile phase A(sodium acetate tetrahydrofuran solution)and mobile phase B[sodium acetate solution-acetonitrile-methanol(20∶40∶40)]at the flow rate of 1.0 mL/min.The excitation wavelength and the emission wavelength of the fluorescence detector were 233 nm and 441 nm,respectively.Results The linear range of methionine sulfoxide was 0.02605-2.605 μg/mL(r=0.9996),the limit of detection was 1.3×10-3 ng,the average recovery was 100.1%and the RSD was 0.3%.Conclusion The method is simple,accurate with high sensitivity,which could be used for the determination of methionine sulfoxide in compound amino acid injection.