Determination of aflatoxin B1 in alcoholic beverages: comparison of one- and two-photon-induced fluorescence

The qualitative and quantitative analysis of aflatoxin B1 in a model system (water/ethanol), in different wines and in beer using one- and two-photon-induced fluorescence is discussed. The absorption and fluorescence properties of aflatoxin B1 depend on the solvent and pH. The two-photon-absorption cross-section was calculated for aflatoxin B1 in beer and wine (σ2 ∼ 25 GM) for excitation at 720 nm. A comparison of the one- and two-photon- induced fluorescence results showed that the disturbance due to background emission originating from matrix constituents is significantly reduced under two-photon-excitation conditions. The limit of detection for the one- and two-photon-induced fluorescence was determined.