Simultaneous determination of triptolide, tripdiolide and tripterine in human urine by high-performance liquid chromatography coupled with ion trap atmospheric-pressure chemical ionization mass spectrometry.

An accurate and selective method for the simultaneous determination of triptolide, tripdiolide and tripterine in human urine using hydrocortisone as an internal standard (IS) by high-performance liquid chromatography coupled with atmosphericpressure chemical ionization mass spectrometry in negative ion mode has been developed. After triptolide, tripdiolide and tripterine in human urine were extracted with ethyl acetate and cleaned by solid-phase extraction with C18 cartridges, a satisfactory separation was achieved on an XDB C₁₈ short column (30 x 2.1 mm i.d., 3 mm) using the mobile phase of acetic acid--ammonium acetate (5 mmol/L, pH = 4.5)--acetonitrile--methanol in gradient elution. Detection was operated by APCI in selected ion monitoring mode. The target ions m/z 359, m/z 375, m/z 449 and m/z 419 were selected for the quantification of triptolide, tripdiolide, tripterine and IS, respectively. The linear range was 1.0--100.0 ngmL^-1, and the limits of quantification in human urine were found to be 0.1-0.5 ngmL^-1 for the three compounds. The precisions (CV%) and accuracies were 6.6-12.9 and 85.1-97.0%, respectively. The developed method could be applied to the determination of triptolide, tripdiolide and tripterine in human urine for diagnosis of the intoxication and for forensic purposes. [ABSTRACT FROM AUTHOR]