Simultaneous separation and determination of three diterpenoids in Euphorbia lathyris L. and its formulations by hydrophobic interaction electrokinetic chromatography.

In this study, a hydrophobic interaction electrokinetic chromatography method has been developed for simultaneous separation and determination of three diterpenoids in Euphorbia lathyris L.: Euphorbia factors L1 , L2 , and L3 . After optimization of separation conditions, the electrolyte solution was 5.0 mM ammonium acetate buffer containing 30 mM sodium dodecyl sulfate in a 60% v/v methanol (pH 6.86), 25 kV of electric field across the capillary was applied at 25°C, and the detection wavelength was at 280 nm. Under optimum conditions, good linearity was achieved with correlation coefficients from 0.9945 to 0.9995. The limits of detection were 2.5, 7.5, and 5.6 μg/mL, and the limits of quantitation were 8.8, 23.9, and 15.3 μg/mL, respectively. Excellent accuracy and precision were obtained. Recoveries of the analytes varied from 98.5 to 103.8%. The established method was novel, simple, and rapid, and it was validated and confirmed to be applicable for the determination of the active ingredients in a quality control analysis.