Accurate determination of fumonisins, secondary metabolites produced by some Fusarium species, in maize and maize-based foods is essential for a reliable evaluation of human exposure to these carcinogenic mycotoxins. This study describes a comparison of analytical methods for quantifying fumonisins (FB1 and FB2) in masa, the alkali-treated maize flour traditionally produced through the nixtamalization process. Two commercial masa flours were analysed by using methanol+water, acetonitrile+methanol+water, methanol+acqueous ethylenediaminetetraacetic acid (EDTA) or acetonitrile+methanol+citrate-phosphate buffer as extraction solvents, strong anion exchange (SAX), immunoaffinity (IMA) or C18 columns for extract clean-up and HPLC/fluorescence detection of o-phthaldialdehyde (OPA) derivatives for fumonisins quantification. The efficacy of extraction solvents was evaluated by comparing fumonisin content in naturally contaminated masa samples and by recovery experiments at spiking levels of 450 and 950 µg/kg FB1 and 150 and 315 µg/kg FB2 (triplicate experiments). Although the extraction with acetonitrile+methanol+water and IMA column clean-up provided higher fumonisins recoveries (up to about 60%), as compared to methanol+water extraction (up to about 20%) and SAX column clean-up, they were still unacceptable according to performance criteria required by Community legislation for fumonisin analysis. The incorporation of the chelating reagent EDTA in the extraction solvent and C18 columns clean-up improved the extraction of fumonisins and gave recoveries higher than 80% for FB1 and FB2, respectively, with relative standard deviations (RSDs) less than 14%. Similar recovery values (96-97% for FB1 with RSDs <2% and 75-86% for FB2, with RSDs <5%) were obtained by using a heat extraction with acetonitrile+methanol+citrate-phosphate buffer and IMA column clean-up. Although these methods gave comparable results, the latter provided better chromatographic profiles due to the specificity of the antibody contained in the IMA columns.
Analysis of deoxynivalenol in wheat by Fourier-Transform Near Infrared (FT-NIR) spectroscopy
De Girolamo A;Pascale M;Visconti A
2009
Abstract
Accurate determination of fumonisins, secondary metabolites produced by some Fusarium species, in maize and maize-based foods is essential for a reliable evaluation of human exposure to these carcinogenic mycotoxins. This study describes a comparison of analytical methods for quantifying fumonisins (FB1 and FB2) in masa, the alkali-treated maize flour traditionally produced through the nixtamalization process. Two commercial masa flours were analysed by using methanol+water, acetonitrile+methanol+water, methanol+acqueous ethylenediaminetetraacetic acid (EDTA) or acetonitrile+methanol+citrate-phosphate buffer as extraction solvents, strong anion exchange (SAX), immunoaffinity (IMA) or C18 columns for extract clean-up and HPLC/fluorescence detection of o-phthaldialdehyde (OPA) derivatives for fumonisins quantification. The efficacy of extraction solvents was evaluated by comparing fumonisin content in naturally contaminated masa samples and by recovery experiments at spiking levels of 450 and 950 µg/kg FB1 and 150 and 315 µg/kg FB2 (triplicate experiments). Although the extraction with acetonitrile+methanol+water and IMA column clean-up provided higher fumonisins recoveries (up to about 60%), as compared to methanol+water extraction (up to about 20%) and SAX column clean-up, they were still unacceptable according to performance criteria required by Community legislation for fumonisin analysis. The incorporation of the chelating reagent EDTA in the extraction solvent and C18 columns clean-up improved the extraction of fumonisins and gave recoveries higher than 80% for FB1 and FB2, respectively, with relative standard deviations (RSDs) less than 14%. Similar recovery values (96-97% for FB1 with RSDs <2% and 75-86% for FB2, with RSDs <5%) were obtained by using a heat extraction with acetonitrile+methanol+citrate-phosphate buffer and IMA column clean-up. Although these methods gave comparable results, the latter provided better chromatographic profiles due to the specificity of the antibody contained in the IMA columns.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
