Determination of 5 Amanita Toxoids in Wild Mushrooms from Wutong Mountain in Shenzhen by High Performance Liquid Chromatography-Triple Quadrupole Tandem Mass Spectrometry

For the case of wild mushroom poisoning from Wutong Mountain in Shenzhen, 23 species of wild mushrooms were collected at the accident site. Simultaneous determination of the 5 Amanita toxoids, including α-amanitin (α-AMA), β-amanitin (β-AMA), phallacidin (PCD), phallisacin (PSC) and phalloidin (PHD), was made by the title method, and the 5 toxins in the fruiting bodies of Amanita exitialis, the only one in which toxins was detected, at different growth periods were investigated. Water of 10 mL was added into 1 g of fresh mushroom or 0.2 g of dried mushroom, and the mixture was homogenized, sonicated for 10 min, and centrifuged for 5 min. An aliquot (1 mL) of the supernatant was taken and passed through a 0.22 μm water phase filtration membrane. The filtrate was analyzed by high performance liquid chromatography-triple quadrupole tandem mass spectrometry. ACQUITY UPLC HSS T3 column was used as stationary phase, and the mixed solution composed of 5 mmol·L^-1 ammonium acetate solution and acetonitrile at different volume ratios was used as mobile phase for gradient elution. The separated targets were ionized under positive ion mode with electricspray ion source, and detected under multiple reaction monitoring mode in the tandem mass spectrometer. It was shown that the mass concentrations of the 5 Amanita toxoids were all linearly related the respective peak areas in the range of 20.0-500.0 μg·L^-1, with the same detection limits (3S/N) of 6 ng·g^-1. The spiked recovery test was made on the blank samples, giving results in the range of 78.3%-98.3%, and RSDs (n=6) of the determined values ranged from 0.30% to 11%. Except for Amanita exitialis, the 5 Amanita toxoids were not detected in the other 22 species among the 23 species of wild mushrooms. α-AMA, β-AMA, PCD and PSC were detected in Amanita exitialis, the total content of toxins was the highest in mature period (1.50 mg·g^-1, wet weight) and the lowest in growing period (1.05 mg·g^-1, wet weight), and detection amount of β-AMA was the highest, following by that of α-AMA.