ABSTRACT
Objecave To develop a sensitive and specific LC-MS/MS method for determination of testolactone in human urine.Methods A C_(18 )column(2.1×50mm,3.5μm) was used.The mobile phase Was a mixture of acetonitrile and the buffer solution(ammonium acetate-water solution adjusted with formic acid to pH 3.5)at a flow rate of 0.5ml/min.A mass spectrometer equipped with electrospray ionization source was used as a detector and operated in the positive mode.In multiple reaction monitoring(MRM)mode,the ion transitions of m/z 301→121 and m/z 301→25 was used to qualify and quantify the testolactone,respectively.Results Chromatograms showed no endogenous interfering peaks with the urine blank sample.Each analysis was completed within 7min The calibration wag linear in the concentration range within 0.1～50μg/ml.The intra-batch and inter-batch RSD were less than 10%.The recovery rate of the extraction was about 60%.Conclusions The method is proved to meet the requirements of WADA and be suitable for routine screening.
ABSTRACT
A method has been developed for the determination of stimulants in products of nutritional supplement. The stimulants in the samples were extracted with a solution of sodium hydroxide and then cleaned up by liquid -liquid partitioning.The extracted stimulants were analyzed by gas chromatography with HP-5capilary column and detected by the Nitrogen-Phosphorus detector (NPD). The results showed that the method had good purifying effect with high sensitivity. The operation was also simple and quick. The detection limit ranged from 5 to 40 ?g/L and the average recovery rate was 75.4%～143.1% with relative standard deviations (RSDs) ranged from 0.27% to 5.5%.
ABSTRACT
To study the chemical constituents of Buddleja lindleyana Fort.. Methods The constituents were isolated and purified by various chromatographic methods and structurally identifed by physico-chemical properties and spectral analysis. Results 10 compounds were obtained as α-spinasterol (Ⅰ), stigmasterol (Ⅱ)， β-sitosterol (Ⅲ), ursolic acid (Ⅳ), oleanolic acid (Ⅴ),phenanthrene (Ⅵ), glycerol mono tetracosanoate (Ⅶ), nonacosane (Ⅷ), acaciin (Ⅸ) and 6-O-vanilloyl-ajugol (Ⅹ). Conclusion All these compounds were obtained from this plant for the first time.