Abstract
Aflatoxin B1, B2, G1 and G2 (AFB1, AFB2, AFG1 and AFG2) were analyzed by thermospray liquid chromatography/mass spectrometry. The ionization efficiency of each aflatoxins (AFs) was stongly affected by the temperatures of the tip point of the vaporizer probe (TIP) and the vapor temperature. By controlling the vapor temperature rather than the TIP temperature, more stable analytical conditions were achieved. The strongest ions of each of the AFs were (M+H)+ followed by (M+NH4)+ and (MH-44)+ and the ratios of these ions were changed by ionization mode. The minimum quantitative limits of AFs were one ng using selected ion monitoring chromatography. The quantitative determination of the four AFs were linear up to 1000 ng. No interference peaks were observed at M/Z 313, 315, 329 and 331, which correspond to (M+H)+ of AFB1, AFB2, AFG1 and AFG2, from samples of maize, peanut meal and mold culture extracts. The minimum quantitative limits of aflatoxins in these samples were about 10 ppb.
