Direct electrochemical detection of trichothecenes in wheat samples using a 96-well electrochemical plate coupled with microwave hydrolysis

Abstract

The use of a 96-well electrochemical plate for the fast and sensitive detection of deoxynivalenol and nivalenol in wheat samples is shown. Deoxynivalenol and nivalenol are hydrolysed using a microwave hydrolysis procedure (2 min) which leads to the production of electroactive compounds that can be sensitively detected by the use of cheap screen-printed electrodes. A procedure of extraction with aqueous acetonitrile and a clean-up step was demonstrated to be suitable for the application with wheat samples providing suitable detection limit (LOD=1.1 µg/g) and working range (2-20 µg/g) for the determination of deoxynivalenol in cereals for feed consumption.

Scientific Opinion on risks for animal and public health related to the presence of nivalenol in food and feed

“…This offers advantages, in principle, for electrochemical measurements. However, the method of Ricci et al (2009) is not able to distinguish between deoxynivalenol and nivalenol and, despite the abovementioned advantages, electrochemical methods for nivalenol may currently found only in academic research circles and (commercial) applications of this approach are not available yet. Ricci et al (2009) applied this approach in an analytical method involving a microwave hydrolysis procedure for the production of electroactive compounds from deoxynivalenol and nivalenol in combination with screen-printed electrodes and a new 96 well electrochemical plate.…”

“…Of interest is the finding of Hsueh et al (1999) that group B trichothecenes give rise to electroactive compounds after a hydrolysis step performed in basic solution. Ricci et al (2009) applied this approach in an analytical method involving a microwave hydrolysis procedure for the production of electroactive compounds from deoxynivalenol and nivalenol in combination with screen-printed electrodes and a new 96 well electrochemical plate. Screen-printed electrodes offer several advantages to the classic electrode surfaces usually adopted in analytical chemistry applications.…”

Rapid and Easy Detection of Deoxynivalenol on a Bismuth Oxide Screen‐printed Electrode

“…The obtained LOD for DON is similar or better than those published for a stripping adsorptive square‐wave voltammetric method on glassy carbon (41 μg L −1 , 1.4×10 −7 mol L −1 ) or carbon paste (3.6 μg L −1 , 1.2×10 −8 mol L −1 ) electrodes and polarographic methods (8.6 μg L −1 , 2.9×10 −8 mol L −1 ) . The reported LOD values for DON determination methods based on hydrolysis procedures prior to the electrochemical measurement, by square‐wave voltammetry (2.7 mg L −1 , 9.1×10 −6 mol L −1 ) or differential pulse voltammetry using 96‐well screen‐printed microplates (1.1 mg L −1 , 3.7×10 −6 mol L −1 ) , are worse than the LOD value for the method proposed in the present paper. Moreover, these methods with a previous hydrolysis are time consuming and increase the risks of analyte loss due to the additional step to perform the analysis.…”

“…Therefore, regardless the characteristics of the techniques and methods employed, extraction and clean‐up steps are usually required. For this reason, more or less laborious clean‐up methods are employed in all published electroanalytical methods for DON determination in real samples. We have explored the applicability of the developed method for the determination of DON in rice samples.…”

“…Most recently, a square wave adsorptive anodic stripping voltammetric method on glassy carbon and carbon paste electrodes has been published for the indirect determination of DON . A 96‐well screen‐printed microplate, with working graphite electrodes has been proposed for detection of DON, but in this work, a hydrolysis procedure is employed, in a microwave digestion system, for the production of electroactive compounds previous to the measurement by Intermittent Pulse Amperometry .…”