Rapid and sensitive determination of the prochloraz residues in the cultivated mushroom, Agaricus bisporus (Lange) Imbach

The QuEChERS ( quick, easy, cheap, efficient, rugged, and safe) sample preparation method and gas chromatography-electron capture detector (GC-ECD) were adopted for rapid extraction and determination of prochloraz residues in cultivated mushrooms. The results were further confirmed by using a gas chromatography-mass spectrometry (GC-MS) system. The method showed that there was a good linear relationship with a correlation coefficient of r(2) = 0.999 in the concentration ranges from 52.9 to 1000 mu g L-1 . The limit of detection (LOD) of the GC-ECD method was 15.9 mu g kg(-1) and the limit of quantification (LOQ) was 52.9 mu g kg(-1) The data satisfactorily demonstrated the good repeatability of the method with relative standard deviations (RSDs) lower than 20%. The recovery values for spiked mushroom samples were 100.6 +/- 1.6% and 105.6 +/- 3.9% for 250 and 1000 mu g kg (-1), respectively. The samples from seven different mushroom growing facilities were analyzed. The residue levels of prochloraz ranged from <LOQ to 105.4 +/- 16.9 mu g kg(-1). Although, this was the first study on determination of prochloraz residues in mushroom samples by GC-ECD after QuEChERS extraction, the adopted method adequately met the validation criteria and was successfully applied to analyze prochloraz residues in the mushroom samples. Therefore, this method could be regarded as a new alternative for routine analysis of trace levels of this most commonly used pesticide in mushroom production.