Enhanced synchronous spectrofluorimetric determination of aflatoxin B1 in pistachio samples using multivariate analysis

The determination of aflatoxin B1 (AFB1) in pistachio has been accomplished by normal and synchronous fluorimetry in combination with some multivariate calibration methods and derivative techniques. Extending the two-dimensional synchronous fluorescence scan to a three-dimensional total synchronous fluorescence scan was used to obtain the optimized Δλ for AFB1 in pistachio sample. The methods are based on the enhanced fluorescence of AFB1 by β-cyclodextrine in 10% (v/v) methanol–water solution. Twenty-six pistachio samples containing AFB1 in the range 0–15 ppb were used as calibration set. Eighteen combinational methods were tested to make best model for prediction of AFB1 and finally best results obtained using a method based on synchronous fluorimetry in combination with multiple linear regressions (MLR). For concentrations ranging from 0 to 15 ppb of AFB1 in 22 pistachio samples as prediction set, the values of root mean square difference (RMSD) and relative error of prediction (REP) using MLR were 0.328 and 4.453%, respectively were observed. Two naturally contaminated pistachio samples were analyzed by synchronous fluorimetry using MLR and compared with HPLC results.