Automated solid-phase extraction coupled online with HPLC-FLD for the quantification of zearalenone in edible oil

Abstract

Established maximum levels for the mycotoxin zearalenone (ZEN) in edible oil require monitoring by reliable analytical methods. Therefore, an automated SPE-HPLC online system based on dynamic covalent hydrazine chemistry has been developed. The SPE step comprises a reversible hydrazone formation by ZEN and a hydrazine moiety covalently attached to a solid phase. Seven hydrazine materials with different properties regarding the resin backbone, pore size, particle size, specific surface area, and loading have been evaluated. As a result, a hydrazine-functionalized silica gel was chosen. The final automated online method was validated and applied to the analysis of three maize germ oil samples including a provisionally certified reference material. Important performance criteria for the recovery (70-120 %) and precision (RSDr <25 %) as set by the Commission Regulation EC 401/2006 were fulfilled: The mean recovery was 78 % and RSDr did not exceed 8 %. The results of the SPE-HPLC online method were further compared to results obtained by liquid-liquid extraction with stable isotope dilution analysis LC-MS/MS and found to be in good agreement. The developed SPE-HPLC online system with fluorescence detection allows a reliable, accurate, and sensitive quantification (limit of quantification, 30 μg/kg) of ZEN in edible oils while significantly reducing the workload. To our knowledge, this is the first report on an automated SPE-HPLC method based on a covalent SPE approach.

Plant organ cultures as masked mycotoxin biofactories: Deciphering the fate of zearalenone in micropropagated durum wheat roots and leaves

“…Analytical standards of ZEN (100 μg mL -1 in acetonitrile), α-ZEL (solution in acetonitrile 10 μg mL -1 ) and β-ZEL (solution in acetonitrile 10 μg mL -1 ) were obtained from Sigma-Aldrich (Taufkirchen, Germany). Zearalenone-14-glucoside (ZEN14Glc) was synthesised and purified in our laboratory [ 4 ], as well as cis -zearalenone [ 14 ]. Zearalenone-16-glucoside (ZEN16Glc) was kindly provided by Prof. Franz Berthiller (IFA-Tulln, University of Natural Resources and Life Science, Vienna).…”

“…Although ZEN largely occurs as trans -isomer, it has been reported that cis -ZEN may be formed upon light exposure and in water, in presence of some ionic species [ 13 ]. The cis -isomer is usually overlooked in food analysis, but its presence in edible plant matrices has been reported and in mammals its metabolites have comparable estrogenicity as trans -ZEN [ 14 – 16 ]. In infected cereals, ZEN may undergo conjugation through glycosylation; zearalenone-14-glucoside (ZEN14Glc) is its most known masked form [ 1 ].…”

Quantification of mycotoxins in vegetable oil by UPLC-MS/MS after magnetic solid-phase extraction

“…Comparing with other sample preparation approaches previously reported for oil analysis, all recoveries of the present MSPE UPLC-MS/MS method are good. As shown in Table 4, analytical figures of this method are compared for several HPLC-based quantitative methods reported for analysis of mycotoxins in oils (Ferracane et al 2007;Majerus et al 2009;Drzymala et al 2015;Li et al 2015).…”

Automation of Solubility Measurements on a Robotic Platform

“…Other research groups use prepacked cartridges, well plates, or disks for automated solid‐phase extractions 6–9. With the preparation of immobilized materials, the combination of liquid and solid handling on an automated platform can be realized.…”