Abstract: An ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was successfully developed for the simultaneous determination of amatoxins (AMA) and phallotoxins in plasma and urine. Guinea pigs were orally administered with α-AMA, β-AMA, phallacidin (PCD) and phalloidin (PHD) at single doses of 1.0, 0.486, 0.079 and 0.120 mg/kg·bw respectively. Plasma and urine samples at different time points were collected and analyzed by the developed method to study the metabolism patterns of these toxins in laboratory animals. The results showed that the limits of detection (LODs) were 0.3 and 1.0 μg/L for urine and plasma, respectively. The average recoveries at three spiked levels of 2–100 μg/L varied from 76.8% to 109.0% with relative standard deviations (RSDs) of 1.30%–12.00% (n = 6). α-Amanitin and β-amanitin rapidly reached the maximum levels of 14.6 and 7.24 μg/L in plasma, respectively at 2 h after administration. At 24 h, the amanitins were near the LODs or were undetectable. However, the phallotoxins were below the LODs in plasma at all time points investigated. All four toxins were detected at concentrations of 45.9–1 905 μg/L in urine at 2 h after administration.

Key words: amatoxin, phallotoxin, ultra performance liquid chromatography-tandem mass spectrometry, plasma, urine