title: Enhanced spectrofluorimetric determination of aflatoxin B1 in wheat by second-order standard addition method.
abstract: Determination of aflatoxin B1 (AFB1) in wheat has been accomplished by enhanced spectrofluorimetry in combination with second-order standard addition method (EF-SOSAM). The adopted strategy combined the use of parallel factor analysis (PARAFAC) for extraction of the pure analyte signal and the standard addition method, for a determination in the presence of matrix effect caused by wheat matrix. The method is based on the enhanced fluorescence of AFB1 by beta-cyclodextrin in 10% (w/w) methanol-water solution. After sample treatment and without any extended cleanup steps and derivatization process, four standard additions were performed for each sample. A specific PARAFAC model was built from three-way arrays formed by excitation-emission spectra and 5 measurements (sample plus 4 additions). The scores related to AFB1 were used for a linear regression in the standard addition method. Two naturally contaminated wheat and spiked wheat samples containing AFB1 in the range 0-18 microg kg(-1) were analyzed by EF-SOSAM and compared with HPLC results. EF-SOSAM analysis of spiked wheat samples gave a good correlation with spiked values (R(2)>0.990). The limit of detection of method was 0.9 microg kg(-1) for the determination of AFB1 in wheat samples.
authors.affiliation: Department of Chemistry, Faculty of Science, Tarbiat Modares University, P.O. Box 14115-175, Tehran, Iran.
authors.forename: Javad
authors.initials: J
authors.lastname: Hashemi
authors.forename: Gholamreza Asadi
authors.initials: GA
authors.lastname: Kram
authors.forename: Naader
authors.initials: N
authors.lastname: Alizadeh
mesh_terms: D016604:Aflatoxin B1 / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence / Q000379:methods*; D013997:Time Factors; D014908:Triticum / Q000737:chemistry*
chemical_list: D016604:Aflatoxin B1