Publikationsdatenbank

Determination of ochratoxin A in grains by immuno-ultrafiltration and HPLC-fluorescence detection after postcolumn derivatisation in an electrochemical cell (2011)

Art

Zeitschriftenartikel / wissenschaftlicher Beitrag

Autoren

Reiter, Elisabeth Viktoria

Cichna-Markl, Margit

Chung, Duck-Hwa

Shim, Won-Bo

Zentek, Jürgen

Razzazi-Fazeli, Ebrahim

Quelle

Analytical and bioanalytical chemistry

Bandzählung: 400

Heftzählung: 8

Seiten: 2615 – 2622

ISSN: 1618-2642

Sprache

Englisch

Verweise

DOI: 10.1007/s00216-011-4942-2

Pubmed: 21461614

Kontakt

Institut für Tierernährung

Königin-Luise-Str. 49
14195 Berlin
+49 30 838 52256
tierernaehrung@vetmed.fu-berlin.de

Abstract / Zusammenfassung

The paper presents a new sample clean-up method based on immuno-ultrafiltration for the analysis of ochratoxin A in cereals. In contrast to immunoaffinity chromatography, in immuno-ultrafiltration, the antibodies are used in non-immobilised form. Ochratoxin A was extracted with ACN/water (60/40, v/v), and the extract was loaded onto the ultrafiltration device. After a washing step with phosphate-buffered saline, containing 0.05% Tween 20, ochratoxin A was eluted with MeOH/acetic acid (99/1, v/v). The detection of ochratoxin A was carried out with high-performance liquid chromatography and a fluorescence detector coupled to an electrochemical cell (Coring cell). The electrochemical cell was used to eliminate matrix interferences by oxidising matrix compounds. The method was validated by repeatedly analysing spiked barley and rye samples as well as a certified wheat reference material. Recoveries and standard deviations (1 SD) were found to be 71 ± 9%, 77 ± 12% and 77 ± 8% in wheat, barley and rye, respectively. The limit of detection (S/N = 3) and limit of quantitation (S/N = 10) were determined to be 0.4 μg kg(-1) and 1 μg kg(-1). The analysis of the certified reference material resulted in ochratoxin A concentrations which were in the range assigned by the producer. Additionally, the effect of the electrochemical cell on other widely used clean-up techniques, namely the immunoaffinity clean-up and multifunctional columns (Mycosep #229), was evaluated. In all clean-up methods, an improvement of the chromatogram quality was registered.