Reduced graphene oxide and gold nanoparticle composite-based solid-phase extraction coupled with ultra-high-performance liquid chromatography- tandem mass spectrometry for the determination of 9 mycotoxins in milk

摘要

A reliable solid-phase extraction (SPE) procedure using reduced graphene oxide and gold nanoparticle (rGO/Au) composite as sorbent was proposed for purification and enrichment of aflatoxin B-1 (AFB(1)), aflatoxin M-1 (AFM(1)), ochratoxin A (OTA), zearalenone (ZEA), alpha-zearalenol (alpha-ZOL), beta-zearalenol (beta-ZOL), zearalanone (ZAN), alpha-zearalanol (alpha-ZAL) and beta-zearalanol (beta-ZAL) in milk. Main parameters affecting the performance of SPE procedure were thoroughly investigated. The optimized conditions included 2% acetonitrile in water as the loading solution, 5% methanol in water as the washing solution, and methanol/acetonitrile/formic acid (50/49/1, v/v/v) as the elution solvent. Satisfactory linearity (R-2 = 0.992), high sensitivity (limit of quantification in the range of 0.02-0.18 ng mL(-1)), adequate recovery (70.2-111.2%), and acceptable precision (RSD, 2.0-14.9%) were obtained when the optimal sample pretreatment protocol was combined with ultra-high-performance liquid chromatography-tandem mass spectrometry detection. The applicability of the validated method was further verified in real milk samples.