A fully automated and fast method using direct sample injection combined with fused-core column on-line SPE–HPLC for determination of ochratoxin A and citrinin in lager beers
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A new fast and sensitive method based on on-line solid-phase extraction on a fused-core precolumn coupled to liquid chromatography with fluorescence detection has been developed for ochratoxin A (OTA) and citrinin (CIT) determination in lager beer samples. Direct injection of 100 μL filtered beer samples into an on-line SPE–HPLC system enabled fast and effective sample extraction including separation in less than 6 min. Preconcentration of OTA and CIT from beer samples was performed on an Ascentis Express RP C18 guard column (5 × 4.6 mm), particle size 2.7 μm, with a mobile phase of methanol/0.5 % aqueous acetic acid pH 2.8 (30:70, v/v) at a flow rate of 2.0 mL min−1. The flow switch from extraction column to analytical column in back-flush mode was set at 2.0 min and the separation was performed on the fused-core column Ascentis Express Phenyl-Hexyl (100 × 4.6 mm), particle size 2.7 μm, with a mobile phase acetonitrile/0.5 % aqueous acetic acid pH 2.8 in a gradient elution at a flow rate of 1.0 mL min−1 and temperature of 50 °C. Fluorescence excitation/emission detection wavelengths were set at 335/497 nm. The accuracy of the method, defined as the mean recoveries of OTA and CIT from light and dark beer samples, was in the range 98.3–102.1 %. The method showed high sensitivity owing to on-line preconcentration; LOQ values were found to be 10 and 20 ng L−1 for OTA and CIT, respectively. The found values of OTA and CIT in all tested light, dark and wheat beer samples were significantly below the maximum tolerable limits (3.0 μg kg−1 for OTA and 2000 μg kg−1 for CIT) set by the European Union.
KeywordsOn-line SPE–HPLC Ochratoxin A Citrinin Mycotoxins Beer Fused-core column
The authors are grateful to the Charles University Grant Agency for grant GAUK no. 1316213. I. Lhotská would like to acknowledge financial support of the project of specific research, no. SVV 260 292. The work was co-financed by the project GAČR no. 15-10781S.
Compliance with ethical standards
Conflict of interest
The authors report no conflicts of interest in this work.
- 10.Flajs D, Peraica M. Toxicological properties of citrinin. Arch Ind Hyg Toxicol. 2009;60:457–67.Google Scholar
- 11.EU. Commission Regulation (EC) No 1881/2006 of 19 December 2006 setting maximum levels for certain contaminants in foodstuffs. Off J Eur Union L. 2006;364:16.Google Scholar
- 12.EU. Commission Regulation (EU) No 212/2014 of 6 March 2014 amending Regulation (EC) No 1881/2006 as regards maximum levels of the contaminant citrinin in food supplements based on rice fermented with red yeast Monascus purpureus. Off J Eur Union L. 2014;67:4.Google Scholar
- 19.Wang L, Wang Z, Gao W, Chen J, Yang M, Kuang Y, et al. Simultaneous determination of aflatoxin B1 and ochratoxin A in licorice roots and fritillary bulbs by solid-phase extraction coupled with high-performance liquid chromatography–tandem mass spectrometry. Food Chem. 2013;138:1048–54.CrossRefGoogle Scholar
- 27.O'Mahony J, Clarke L, Whelan M, Kennedy R, Lehotay SJ, Danaher M. The use of ultra-high pressure liquid chromatography with tandem mass spectrometric detection in the analysis of agrochemical residues and mycotoxins in food - challenges and applications. J Chromatogr A. 2013;1292:83–95.CrossRefGoogle Scholar
- 33.Franco CM, Fente CA, Vazquez B, Cepeda A, Lallaoui L, Prognon P, et al. Simple and sensitive high-performance liquid chromatography-fluorescence method for the determination of citrinin application to the analysis of fungal cultures and cheese extracts. J Chromatogr, A. 1996;723:69–75.CrossRefGoogle Scholar
- 43.EU. Commission Regulation (EU) No. 105/2010 of 5 February 2010 amending Regulation (EC) No. 1881/2006 setting maximum levels for certain contaminants in foodstuffs as regards ochratoxin A. Off J Eur Union L. 2010;35:8.Google Scholar