Monitoring of aflatoxins in Egyptian hot chili prepared for export using GPC as a new cleanup technique and reversed phase-HPLC

New method was developed for determination of aflatoxins BI, B2,G1 and G2 in hot chili using gel permeation chromatography [GPC as a new clean up technique. High performance liquid chromatography [HPLC] connected with fluorescence detector was used for determination of the four types of aflatoxin. The method was tested on different levels of fortified samples of hot chili [6 sample for each level] and the limit of detection [LOD] was [0.5 ph]. The average recoveries of aflatoxins from different levels [2,4,10 and 50 ppb] varied between 87 and 107%. The reproducibility expressed as relative standard deviation was less than 20%. The method showed to be linear from the limit of quantitation [2 ug/kg] up to 50 ug/kg level. The four types of aflatoxins were determined in fortified samples by extraction with acetonitrile and purified by GPC, [[Bio bead - SX 3 gerl] was used as stationary phase and hexane: ethyl acetate [1:1] as mobile phase]. Drivatiztion of B1 and G1 were obtained by reaction with trifluoroacetic acid [TEA] in a pre-column step. Quantitation of aflatoxins is carried out using reversed phase high performance liquid chromatography with isocratic mobile phase water/methanol/acetonitrile [65:25:15%]. The detection was done at excitation and emission wavelengths of 360 and 440 nm respectively. This method wss used for monitoring of aflatoxins in 87 hot chili samples prepared for export. Only aflatoxins B1 and B2 were detected and all samples were free from any traces of G1 and G2. Sixty samples were contaminated with aflatoxin B1 and only 20 samples were contaminated with aflatoxin B2. The minimum amount of B1 and B2 was 0.5 ppb LOD], while the maximum amounts were 78.95 and 5.21 ppb respectively. The means were 18.57 and 1.80 ppb for B1 and B2 respectively. Forty six samples were violated with aflatoxin B1 depending on EU MRL limits [2 ppb] when 27 samples were violated depending on CODEX-MIRL limits [5 ppb]