New reversed-phase liquid chromatographic method to detect aflatoxins in food and feed with cyclodextrins as fluorescence enhancers added to the eluent.
The effect of succynil-beta-cyclodextrin (beta-CD-Su), dimethyl-beta-cyclodextrin (DIMEB) and beta-cyclodextrin (beta-CD) on the fluorescence of aflatoxins B1, B2, G1, G2 and M1 (AFB1, AFB2, AFG1, AFG2 and AFM1) was studied: beta-CD-Su promoted the largest fluorescence enhancement for AFB1 and AFM1 while DIMEB showed better results for AFG1 . On the basis of the fluorescence enhancement, a new RP-HPLC method for detecting aflatoxins B1, B2, G1, G2 and M1 was developed using cyclodextrins directly dissolved in the LC eluent. Aflatoxins B1, B2, G1 and G2 were resolved using a MICRA NPS ODS-1 column using methanol-water as mobile phase to which 6 x 10(-3) M beta-CD-Su or beta-CD were added. Chromatographic responses of AFB1 and AFG1 achieved using beta-CD dissolved in the mobile phase were enhanced, respectively, 8 and 12 times, and 10 and 15 times with beta-CD-Su. Detection limits lower than 0.3 microg/kg were achieved for all the four aflatoxins. Aflatoxin M1 was analysed using a Spherisorb S3 ODS-2 Narrow Bore column and methanol-water as mobile phase with added 2 x 10(-3) M beta-CD-Su. An area enhancement of 1.5 was detected for the toxin and the detection limit achieved under these analytical conditions was lower than 0.0005 microg/kg. Both methods were statistically validated showing a linear response for all the aflatoxins tested (R2 > or = 0.99), and applied to the analysis of spiked and naturally contaminated food samples.
Chiavaro
E
E
Dipartimento di Chimica Organica e Industriale dell'Università, Parma, Italy.
Dall'Asta
C
C
Galaverna
G
G
Biancardi
A
A
Gambarelli
E
E
Dossena
A
A
Marchelli
R
R
D000348:Aflatoxins / Q000032:analysis*; D000821:Animal Feed / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D003505:Cyclodextrins / Q000737:chemistry*; D005504:Food Analysis; D012680:Sensitivity and Specificity; D013050:Spectrometry, Fluorescence
D000348:Aflatoxins; D003505:Cyclodextrins