Speciation analysis of mercury in wild edible mushrooms by high-performance liquid chromatography hyphenated to inductively coupled plasma mass spectrometry

Abstract

Wild edible mushrooms can accumulate significantly elevated levels of mercury from the surrounding environment, which could be harmful to consumers' health. Speciation analysis of mercury in wild edible mushrooms aids in understanding the human exposure to these toxic compounds. In this study, we developed a high-performance liquid chromatography hyphenated to inductively coupled plasma mass spectrometry (HPLC-ICP-MS) method for the simultaneous determination of inorganic mercury (Hg(II)), methylmercury (MeHg), ethylmercury (EtHg), and phenylmercury (PhHg) in wild edible mushrooms. A rapid separation of four target mercury species was achieved within 11 min by a C8 column without utilizing high proportion of organic phase in HPLC. The parameters affecting the extraction efficiency of mercury in samples have been investigated. The proposed method showed good linearity within 0-50 μg/L with the detection and quantification limits of 0.6-4.5 μg/kg (S/N = 3), and 2.0-15 μg/kg (S/N = 10), respectively. This proposed method was successfully applied to the mercury speciation analysis in 7 varieties (95 samples) of wild edible mushrooms. The results indicated that in most mushroom samples, mercury mainly occurred as inorganic mercury. But there were two Tricholoma matsutakes, one contained 0.14 mg/kg of methylmercury, another contained 1.05 mg/kg of phenylmercury, which were higher than the maximum allowable content of total mercury in edible mushrooms in China. Graphical abstract.

Keywords: High-performance liquid chromatography; Inductively coupled plasma mass spectrometry; Mercury; Speciation analysis; Wild edible mushroom.