Determination of Reference Standards of Four Moxifloxacin Hydrochloride Impurities by Quantitative Proton Nuclear Magnetic Resonance
OBJECTIVE To establish a quantitative proton nuclear magnetic resonance(qHNMR)method for determination of the reference standards of moxifloxacin hydrochloride impurities A,B,C and D.METHODS Proton nuclear magnetic resonance(1H-NMR)spectra of four reference standards of impurities were obtained in dimethylsulfoxide-d6(DMSO-d6)or chloroform-d(CDCl3)using a nuclear magnetic resonance spectrometer.The internal standard was 1,3,5-trimethoxybenzene.All 1H-NMR spectra for quantitative analysis were measured with noesyigld1d pulse sequence using the following experimental parameters:32 number of scans(NS),relaxation delay time(DI)of 30 s,25 ℃ testing temperature.RESULTS The quantitative peak signals of four moxi-floxacin hydrochloride impurities and 1,3,5-trimethoxybenzene were well separated on 1H-NMR spectra,and the linear relationship was good within the linear range(r2>0.999 4).The injection precision and repeatability of the method were good.The contents of four reference standards of impurities determined by qHNMR method were basically consistent with those determined by mass balance method.CONCLUSION The established qHNMR method is accurate,reliable,simple,fast,which provides a new way for content determination of these impurities and can also be used as a mutual verification method for the calibration results of these reference sub-stance by the mass balance method.
quantitative proton nuclear magnetic resonancemoxifloxacin hydrochloride impurityreference standardcharacter-izationcontent determination