Abstract:

The results were compared for determining gentamycin C components by high performance liquid chromatography with different detectors in pharmacopoeias. Evaporative light-scattering detector (ELSD) was first used in Pharmacopoeia of People’s Republic of China （ChP） 2005, while British Pharmacopoeia （BP） 2005 adopted pulsed amperometric detector in quantitative analysis of gentamycin. As gentamycin C components could not produce signals using UV detector, pre-column derivatization method made the detection possible, referring to United State Pharmacopoeia （USP） 29th Ed, etc. However, the absorbance of by-products and reagents overlapped with gentamycin C components, which caused much trouble in integrating peaks. That is the reason that the quantitative results were calculated based on area and height in different editions of ChP. To make the determination more accurate, “pure” chromatogram was resolved by heuristic evolving latent projection (HELP) method， based on calculating the data obtained with high performance liquid chromatography-diode array detection (HPLC-DAD) using pre-column derivatization with o-phthalic aldehyde （OPA）. After subtracting the interference of impurities, gentamycin C1 component in samples was quantitatively determined accurately. The results were comparable to what achieved with HPLC-evaporative light-scattering detector and column switching. At the same time, it was proved that the HPLC-ELSD method in ChP 2005 was more reliable than the pre-column derivatization method.

Key words: column switching, evaporative light-scattering detection （ELSD）, gentamycin C , heuristic evolving latent projection, o-phthalic aldehyde pre-column derivatization-diode array detection, high performance liquid chromatography （HPLC）