Determination of 5 Mycotoxins in Quzhou Aurantii Fructus by Ultra-High Performance Liquid Chromatography-Tandem Mass Spectrometry with Composite Immunoaffinity Column Purification

The method mentioned by the title was proposed to determine aflatoxin B₁, B₂, G₁, G₂, and ochratoxin A in Quzhou Aurantii Fructus samples. After ultrasonic extraction on the sample in the mixed solution composed of acetonitrile, water and acetic acid at volume ratio of 79∶20∶1, the extract was centrifuged. The supernatant was diluted by phosphate buffer solution (pH 7.0), purified with a composite immunoaffinity column, and filtered. The targets in the filtrate was separated on the XDB C₁₈ chromatographic column using mixed solutions composed of methanol-5 mmol·L⁻¹ ammonium acetate mixed solution (volume ratio of 1∶9) and methanol-5 mmol·L⁻¹ ammonium acetate mixed solution (volume ratio of 9∶1) at different volume ratios, detected by the ESI⁺ and MRM modes, and quantified by the isotope internal standard method. It was shown that linear relationships between values of the mass concentration ratio and corresponding peak area ratio of the 5 mycotoxins to their isotope internal standards were kept in definite ranges, with detection limits in the range of 0.05-0.20 μg·kg⁻¹. Recoveries of the 5 mycotoxins in negative samples at three spiked concentration levels ranged from 82.7% to 97.3%, and RSDs (n=6) of the determined values were in the range of 5.2%-12%.