High-performance liquid chromatography with post-column derivatisation and fluorescence detection for sensitive determination of aflatoxin M1 in milk and cheese

Occurrence of Aflatoxin M1 in Dairy Products

“…In past years, TLC methods have also been widely used and, even more recently, a TLC protocol to determine AFM1 in milk has been reported and validated (Grosso et al, 2004). As regards cheese and other dairy products, some instrumental analysis methods have been described (Oruc et al, 2006;Kamkar et al, 2008;Mendonca & Venancio, 2005;Govaris et al, 2001;Deveci, 2007;Hisada et al, 1984;Pietria et al, 1997;Manetta et al, 2005). Validation according to EU regulation has been reported for an LC-FLD method applied to yogurt (Tabari et al, 2011).…”

“…Schematically, confirmatory analytical protocols consist of: (i) extraction of the toxin with some organic solvent (dichloromethane, chloroform, methanol, acetonitrile); (ii) clean-up, which usually exploits the affinity and selectivity of antibodies immobilized in a solid-phase extraction (SPE) column (Immuno Affinity Chromatography) to reduce matrix interfering components and to strongly concentrate the target compound; alternatively C18-SPE is used for the purpose; (iii) chromatographic separation by reverse-phase HPLC; (iv) detection of the native fluorescence of AFM1. In 2005, Manetta and co-workers described a particularly sensitive method of analysis (LOD as low as 1 ng/kg in cheese) which used post-column derivatisation to enhance AFM1 fluorescence (Manetta et al, 2005). Mass spectrometric detection has also been successfully applied for the determination of AFM1 in different types of cheese samples (Cavaliere et al, 2006) and for the simultaneous detection of the toxin with other eight mycotoxins (Kokkonen et al, 2005).…”

Aflatoxins: Their Measure and Analysis

“…Initially, the post-column reaction used iodination (Shepherd & Gilbert, 1984), but it has several disadvantages, like peak broadening and the risk of crystallisation of iodine. An alternative method is represented by bromination by an electrochemical cell (Kobra Cell) with potassium bromide dissolved in an acidified mobile phase or by addition of bromide or pyridinium hydrobromide perbromide (PBPB) to mobile phase and using a short reaction coil at ambient temperature (Stroka et al, 2003;Manetta et al, 2005;Senyuva & Gilbert, 2005;Brera et al, 2007;Manetta et al, 2010). The www.intechopen.com bromination methods offer the advantage to be rapid, simple and easy to automate, improving reproducibility and ruggedness and reducing analysis time.…”

Sensitive detection of aflatoxin B1 molecules on gold SPR chip surface using functionalized gold nanoparticles

“…It is very useful to develop new and more sensitive methods for quantitative determination of hydrophobic molecules (Du et al 2007;Kham et al 2007;Pál et al 2009;Varga et al 2009). Although numerous procedures can detect and determine the aflatoxin derivatives, the most typical one is the time-delayed analysis of aflatoxin derivatives by thin-layer chromatography, high-performance liquid chromatography, overpressuredlayer chromatography, and enzyme-linked immunosorbent assay (Li and Zhang 2009;Manetta et al 2005;Moricz et al 2007;Peiwu et al 2009;Urusov et al 2014b;Var et al 2007). The detection of mycotoxins by SPR from food-stuff has already been reported in several publications and those with low molecular weight (aflatoxin, ochratoxin A) were determined by SPR immunosensors (Daly et al 2000;Hodnik and Anderluh 2009;Homola 2008;Li et al 2012;Yuan et al 2009).…”