Incidence and abundance of mycotoxins in maize in Rio Grande do Sul, Brazil.

The levels of aflatoxins B1, B2, G1, and G2, ochratoxin A, zearalenone and sterigmatocystin were determined by thin-layer chromatography in 36 samples of stored maize in the state of Rio Grande do Sul; the samples were obtained from May to September 1988, 23 samples were from silos and 13 samples were collected directly from farms. In 34.8% of the samples from silos aflatoxin B1+G1 was detected in concentrations that varied from 12 to 906 micrograms/kg. In 13% of the samples from silos aflatoxin B2 was detected in concentrations that varied from 48 to 180 micrograms/kg. In 9% of the samples from silos aflatoxin G2 was detected in concentrations that varied from 6 to 11 micrograms/kg. In 23% of the samples collected directly from farms aflatoxin B1+G1 was detected in concentrations that varied from 10 to 14 micrograms/kg. Ochratoxin A, zearalenone and sterigmatocystin were not detected at any time.