Quantitative analysis of lovastatin in capsule of Chinese medicine monascus by capillary zone electrophoresis with UV-vis detector.

A capillary zone electrophoresis (CZE) method was developed for the quantitative analysis of lovastatin (Lvt) in capsule of monascus-Chinese medicine. Lvt in the capsule was separated using an electrolyte system consisting of 16% ethanol (v/v) in 60 mM Gly-sodium hydroxide buffer, pH 10.5, 16 kV applied voltage, 238 nm detection wavelength with a capillary of 51 cm x 75 microm i.d (43 cm to detector). Under the optimized conditions, the linear response of Lvt concentration ranges from 4.0 to 240 microg/mL with high correlation coefficient (r=0.9998, n=9), the limits of detection (LOD) and quantification (LOQ) for Lvt are 0.73 and 2.42 microg/mL, the precision values (expressed as R.S.D.) of intra-day and inter-day are 1.40-2.12% and 1.47-3.88%, respectively. The recoveries of the analyte at three concentration levels are 90.28-100.71%. The developed method can be well used for the quantification of Lvt in the drug in commercial formulations.