[Spectrophotometric investigations on aflatoxin B1 and aflatoxin G1 (author's transl)]

UV-spectrophotometric and fluorescence-spectrophotometric investigations have been performed on the aflatoxins B1 and G1 with the aim of their unequivocal identification and quantitative estimation in the routine examination. The lower limits of the quantitative and semiquantitative estimations have been found to be 0,4 ng (thin layer chromatography, semiquantitative), Imug/ml (UV-spectroscopy) and 10 ng/ml (fluorescence spectroscopy) for the aflatoxin B1 and 0,3 ng (TLC, semiquantitative), 1 mug/ml (UV-spectroscopy) and 1 ng/ml (fluorescence spectroscopy). Quinine sulfate in 0.1 n sulfuric acid was successfully utilized as a convenient standard substance for quantitative fluorescence spectroscopic estimations of the aflatoxins B1 and G1. In an extensive series of estimations the fluorescence intensity of aflatoxin B1 in chloroform in the range of 0,01-10 mug/ml has been compared with that of equally concentrated solutions of quinine sulfate in sulfuric acid. The ratio of the intensities was 0.5 : 1(0.509 : 1). Similar comparative estimations of aflatoxin G1 in chloroform in the range of 0.001 bis 1 mug/ml and quinine sulfate in sulfuric acid resulted in a ratio of 5 : 1 (4.99 : 1). These ratios have been found using a fluorescence spectrophotometer Beckman SF 1078.