[Determination of triptolide in extract from leigongteng (Tripterygium Wilfordii Hook. F.) by RP-HPLC].

A reversed-phase liquid chromatographic method has been developed and validated for the analysis of triptolide in extract from Leigongteng (Tripterygium Wilfordii Hook. F.). The drugs were eluted with petroleum-ethyl acetate on a neutral alumina cartridge and then measured by HPLC using a Hypersil C18 column and acetonitrile-water (40:60, V/V) mobile phase. Triptolide was quantified by ultraviolet absorbance at 210 nm. The method proved to be linear in the range of 0.25-4.00 mg/L with a regression coefficient of 0.9997. The lower limit of detection of triptolide was 0.1 mg/L. Intra-day and inter-day coefficients of variation of assay for triptolide were 1.9%-6.5% (n = 5) and 2.7%-7.8% (n = 5), respectively. The recoveries of the method were 89.8%-92.0%.