Validation of an analytical method to determine the content of ochratoxin A in animal feedFunded under: FP7-KBBE
An inter-laboratory comparison was carried out to evaluate the effectiveness of a method based on immunoaffinity column clean-up followed by high performance liquid chromatography using fluorimetry (HPLC-FL). The method was tested for the determination of ochratoxin A (OTA) in animal feed at concentration levels relevant to those proposed according to Recommendation 576/2006/EC (i). The test portion of the sample was extracted with methanol: water. The sample extract was filtered, diluted, passed over an immunoaffinity column for clean-up and then eluted with methanol. The separation and determination of the OTA was performed by reverse-phase high performance liquid chromatography (HPLC) with fluorescence detection with an excitation of 333 nm and emission of 467 nm. The animal feed samples, both spiked and naturally contaminated with OTA, were sent to 35 laboratories in 15 EU Member States, Colombia, Canada and Japan. Each laboratory received 6 duplicate samples - 4 coded and 2 blanks for spiking with coded solutions. Blank marked test portions of the samples were spiked at levels of 76 mu g/kg and 305 mu g/kg OTA. The range of single recovery values reported spanned from 47 % - 124 % with an average value of 82 % and 79 % for each level respectively. Based on results for spiked samples (blind duplicates at two levels), as well as naturally contaminated samples (blind duplicates at three levels), the relative standard deviation for repeatability (RSDr) ranged from 3.1 % - 4.7 %. The relative standard deviation for reproducibility (RSDR) ranged from 13.5 % - 14.6 %. After correction for recovery, the RSDR values improved significantly and for naturally contaminated test materials ranged from 5.6 % - 6.4 %. This method therefore showed acceptable within-laboratory and between-laboratory precision for each matrix.
Bibliographic Reference: EUR 23657 EN (2009), 54 pp. Free of charge
Availability: http://bookshop.europa.eu/is-bin/INTERSHOP.enfinity/WFS/EU-Bookshop-Site/en_GB/-/EUR/ViewPublication-Start?PublicationKey=LANA23657 (Catalogue Number: LA-NA-23657-EN-C)
ISBN: ISBN: 978-92-79-11063-4
Record Number: 200910267 / Last updated on: 2009-09-22
Original language: en
Available languages: en