Resolution of Aflatoxins B1, B2, G1, and G2 by High-Pressure Liquid Chromatography

Abstract

Aflatoxins were completely resolved as sharp peaks in the order B₁-B₂-G₁-G₂ by high-pressure liquid chromatography on a small particle (10 μm) porous silica gel column in 7–13 min (B₁ through G₂) by a water-saturated chloroform-cyclohexane-acetonitrile elution solvent (25+7.5+1.0), with detection by ultraviolet absorbance at 360 nm. The relationship between peak height and amount injected was linear over a 5–400 ng range for each aflatoxin. Both retention times and peak heights were highly reproducible, multiple injections of mixed standards giving coefficients of variation of 1.0–1.4% (retention time) and 1.6–2.8% (peak height) for the 4 aflatoxins. Detection was highly sensitive, with mean peak height, mm/ng, of 7.1 (B₁), 6.4 (B₂), 4.5 (G₁), and 4.1 (G₂), allowing detection of 1–2 ng of each aflatoxin.