Determination of 187 pesticide residues in edible fungi by liquid chromatography-tandem mass spectrometry

A rapid and sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method is developed for simultaneous determination of 187 pesticide residues in edible fungi. Samples of edible fungi (20 g) were homogeneously extracted with acetonitrile, the extracts were cleaned up using stacked solid-phase extraction (SPE) cartridges containing graphitized carbon black and aminopropyl sorbents. The residue pesticides were eluted with acetonitrile-toluene (3 : 1, v/v), and the eluates were concentrated and used for analysis. In the linear range of each pesticide, the linear correlation coefficient R-2 was equal to or greater than 0.990. At low and high fortification levels, recoveries ranged from 70% to 118%. The relative standard deviation (RSD) was always below 30% and was below 25% for 169 pesticides, accounting for 90%. The limit of detection (LOD) was 0.01-85 mu g kg(-1), 165 pesticides had LOD <= 10 mu g kg(-1), accounting for 88%. The proposed method is suitable for determination of 187 pesticide residues in shiitake, black fungus, nameko and enoki mushroom.