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A sensitive method has been developed and validated for the simultaneous determination of triptolide, tripdiolide, and tripterine in human serum using hydrocortisone as an internal standard (IS). After triptolide, tripdiolide, and tripterine in human serum were extracted with ethyl acetate, the extracts were separated on an XDB C(18) column (30 mm x 2.1-mm i.d., 3 microm) using a mobile phase of acetic acid/ammonium acetate (5 mmol/L, pH 4.5)/acetonitrile/methanol in gradient elution. Detection was performed by high-performance liquid chromatography coupled with atmospheric-pressure chemical ionization ion trap mass spectrometry in negative multiple reaction monitoring mode. The transition ions m/z 359 --340, m/z 375 --357, m/z 449 --405, and m/z 419 --329 were selected for the quantification of triptolide, tripdiolide, tripterine, and IS, respectively. The linear range was 1.0-100.0 ng/mL, the absolute recoveries were between 78.3 and 89.2%, the relative recoveries were between 88.1 and 94.6%, and the limits of quantification in human serum were 0.5-1.0 ng/mL for the three target compounds. The intra- and interday relative standard deviations were less than 11.9% and 13.0%, respectively. This method was found to effectively and simultaneously determine trace triptolide, tripdiolide, and tripterine in human serum and can be suitable for clinical and toxicological studies.

Euonine and wilforidine are biologically active Tripterygium wilfordii Hook. f. alkaloids. In this paper, a rapid and sensitive high-performance liquid chromatography-mass spectrometry (MS) method was developed and validated for the simultaneous determination of trace euonine and wilforidine in human plasma. An Oasis® mixed-mode cation-exchange polymeric sorbent was used for solid-phase extraction. The separation was carried out on a reversed-phase Zorbax Plus C18 column (50 mm × 2.1 mm, 1.8 μm) by using ammonium acetate (5 mmol/L)/acetonitrile (30/70, v/v) as the mobile phase at a flow rate of 0.7 mL/min. The quantification was carried out via ion trap MS in the positive selected ion monitoring mode using aconitine as an internal standard. Calibration curves showed good linearity ranging from 0.5 to 100.0 μg/L with correlation coefficient values >0.9990. The average recoveries of euonine and wilforidine ranged from 85.4 to 101.0% and 92.0 to 97.5%, respectively. The intra- and interday relative standard deviations were

Measurement of indandione rodenticides is important in the diagnosis and treatment of accidental rodenticide ingestion. Current assays lack effective measurements for simultaneous analysis of the indandiones, especially the isomers. The intent of this study was to establish a novel and selective method for the simultaneous determination of indandione-type rodenticides (diphacinone, chlorophacinone, valone, and pindone) in human serum by liquid chromatography-electrospray ionization-tandem mass spectrometry. After addition of internal standard, the sample was extracted with 10% methanol in acetonitrile and cleaned by solid-phase extraction (SPE). The analytes were separated on a C(18) rapid column and infused into an ion trap mass spectrometer in the negative electrospray ionization mode. The multiple-reaction monitoring ion pairs were m/z 339 --> 167, m/z 373 --> 201, m/z 229 --> 145, m/z 229 --> 172, and m/z 307 --> 161 for diphacinone, chlorophacinone, valone, pindone, and IS, respectively. Recoveries were between 81.5 and 94.6%, and the limits of quantification were 0.2 to 0.5 ng/mL. Intra- and interday RSDs were less than 7.9 and 11.5%, respectively. The assay was linear in the range of 0.5-100.0 ng/mL with coefficients of determination (r(2) > 0.99) for all analytes. The proposed method enables the unambiguous confirmation and quantification of the indandiones in both clinical and forensic specimens.

Valone is a chronic anticoagulant rodenticide that has come into wide use in China. Current literature lacks analytical methods for the determination of valone. In this paper, a sensitive and selective assay was established for the identification and quantification of valone in serum by liquid chromatography-tandem mass spectrometry. After addition of the internal standard, warfarin, serum samples were extracted with 10% methanol in acetonitrile and cleaned using Oasis HLB solid-phase extraction (SPE) cartridges. The compounds were separated on an Agilent SB C18 column with a mobile phase of methanol/acetic acid-ammonium acetate (5 mmol/L, pH 6.3) (75:25, v/v). Detection was performed by electrospray ionization ion trap mass spectrometry in the negative multiple reaction monitoring mode. The transition ions of m/z 229 --> 145 and m/z 307 --> 161 were selected for quantification of valone and the internal standard, respectively. The overall extraction efficiency was between 81.1% and 91.1%. The limit of quantification was 0.5 ng/mL. Regression analysis of the calibration data revealed good correlation (r(2) > 0.99) for valone. Intra- and interday precisions for quality-control samples were less than 7.8% and 12.8%, respectively. This method combines a rapid SPE procedure with an extremely fast chromatographic analysis, which is especially advantageous or clinical laboratories.