Monitoring the levels of deoxynivalenol (DON) in cereals in Lebanon and validation of an HPLC/UV detection for the determination of DON in crushed wheat (bulgur)

Abstract

This paper reports for the first time a method for determining deoxynivalenol (DON) in crushed wheat (bulgur) using an high-performance liquid chromatography (HPLC) method with ultraviolet light detection. Linearity (r ² > 0.999), selectivity and recovery (70–110%) were acceptable. Results show that the limit of detection (LOD) was 50 µg kg⁻¹ and the limit of quantification (LOQ) was 80 µg kg⁻¹. The level of DON was determined in 165 samples of cereals – wheat, forkha (wheat flour special for cake) and bulgur (crushed wheat) – marketed in Lebanon. The results showed that the contamination with DON was 8.75%, 7.5% and 5.0% in bulgur, wheat and forkha, respectively. The LOD and LOQ for wheat (or forkha) were, respectively, 40 and 50 µg kg⁻¹. The level of DON in all samples was below 1250 µg kg⁻¹ as recommended by European Union Directives (Commission Regulation (EC) No. 1126/2007), except for one sample of wheat which contained 2307 µg kg⁻¹. These data suggest that the Lebanese population is exposed to DON through food ingestion at concentrations lower than the tolerable daily intake (TDI) and suggest that measures must be performed routinely to avoid high levels of DON contamination to be found on Lebanese market.

Keywords:

• high-performance liquid chromatography (HPLC)
• mycotoxins – trichothecenes
• cereals and grain

Acknowledgements

The authors would like to acknowledge Mr Boutros Kerbaje (Libios) for the supply of materials and reagents. This work was supported by the ‘Programme CEDRE’ and the ‘Conseil de la recherche – Université St Joseph’.