[Determination of the conversion of air oxidation of penicillin derivatives by high performance liquid chromatography].

In air oxidation of penicillin G p-methoxybenzyl ester (PGPMB) to its sulfoxides (PGPMBO), sol-gel technique was employed to encapsulate the catalyst Co (acac)3, by which the reaction was run under heterogeneous conditions. A reversed-phase high performance liquid chromatographic method was established for the determination of the conversion of this reaction. The analysis of PGPMBO was carried out on a C18 column (4.6 mm i.d. x 150 mm, 10 microm) with the mobile phase of methanol-water (85:15, V/V), at a flow rate of 1 mL min(-1) and with detection wavelength of 270 nm. The linearity of the calibration curve of PGPMBO was obtained over the range of 0.05 g x L(-1) - 0.40 g x L(-1) with a relative coefficient of 0.999 2. The highest conversion was 98.8%. The method can be applied to determine this conversion promptly in the reaction system.