Development of an LC-MS/MS method for the determination of aflatoxins B1, B2, G1, and G2 in Brazil nut

An LC-MS/MS method with atmospheric pressure chemical ionization in the positive mode [M + H](+), for simultaneous determination of the aflatoxins (AFLs): AFB(1), AFB(2), AFG(1), and AFG(2) in Brazil nuts matrix is described. By means of multiple reaction monitoring it was possible to analyse the AFLs fragment ions to increase specificity and sensitivity. The separation of the toxins was carried out in a C-8 column with gradient mobile phase composed of water:methanol (25 mM ammonium acetate) in a total run time of 5.0 min. The toxin extraction solvent was acetonitrile: water (80: 20) and no clean up was required for tile Brazil nut samples. The method values of LOD and LOQ utilizing the Brazil nut matrix for AFB(1), AFB(2), AFG(1), and AFG(2) were 0.04; 0.045; 0.050 and 0.060 mu g kg(-1); 0.08, 0.09, 0.10 and 0.12 mu g kg(-1), respectively. The recoveries from the Brazil nuts were between 92 and 100% and Sigma AFL levels obtained from the positive naturally contaminated Brazil nuts ranged from 1.2 to 11.5 mu g kg(-1).