Aflatoxin screening by MALDI-TOF mass spectrometry

Efficient detection of aflatoxins B-1, B-2, G(1), and G(2) has been performed by matrix-assisted laser desorption/ ionization time-of-flight mass spectrometry using a UV-absorbing ionic liquid matrix to obtain matrix-free mass spectra and addition of NaCl to enhance sensitivity via Na+ cationization. Using ionic alpha-cyano-4-hydroxycinnamic acid (Et3N-alpha-CHCA) as the matrix, matrix-free mass spectra in the m/z range of interest are acquired, and the B-1, B-2, G(1), and G(2) aflatoxins are readily detected with an LOD as low as 50 fmol. The technique is fast, requires little sample preparation and no derivatization or chromatographic separation, and seems therefore to be suitable for high-throughput aflatoxin screening. It should be easily extended to other micotoxins and provide an attractive technique to control the quality of major crops subjected to huge world commercial trades such as peanuts, corn, and rice as well as to monitor bioterrorism threats by micotoxin poisoning.