Vortex-assisted dispersive liquid-liquid microextraction for the analysis of major Aspergillus and Penicillium mycotoxins in rice wine by liquid chromatography-tandem mass spectrometry

Abstract

The presence of Aspergillus and Penicillium species during the fermentation process of rice wine is inevitable. The toxic secondary metabolites produced by the two fungi need to be practically monitored for rice wine safety. In this study, we developed a fast and simple vortex-assisted dispersive liquid-liquid microextraction (VADLLME) for the extraction and preconcentration of major Aspergillus and Penicillium mycotoxins (aflatoxin B1, aflatoxin B2, aflatoxin G1, aflatoxin G2, ochratoxin A, mycophenolic acid, sterigmatocystin and verruculogen) in rice wine. The key parameters affecting the extraction efficiency of VADLLME procedure (pH value, type and volume of extraction and dispersive solvents) were optimized by response surface methodology (RSM) combined with Box-Behnken design (BBD) and desirability function. Target compounds were analyzed by liquid chromatography tandem mass spectrometry (LC-MS/MS). Under the optimum conditions, good linearity (R2>0.99) was achieved for all the analytes in the concentration range of 0.5–100 μg/L. The recoveries for spiked samples at three concentration levels were between 84.5% and 111.2%, with the relative standard deviations (RSD) lower than 20%. The limits of detection (LOD) and quantification (LOQ) ranged from 0.05 to 0.5 μg/L and from 0.1 to 1.0 μg/L, respectively. Simplicity in operation, low cost and low usage of organic solvents were the major advantages of the developed method. The method was successfully applied to the analysis of rice wine samples. It was found that mycophenolic acid had high incidence rate in rice wine, which needed to be continuously monitored.