Validation of analytical methods to determine the content of aflatoxin, ochratoxin and patulin in foodstuffs of vegetable origin
An HLPC method for ochratoxin A using immunoaffinity column clean-up was collaboratively tested at three levels of ochratoxin A in barley which were in the region of proposed European regulatory limits. The test portion was extracted with acetonitrile/water by blending at high speed. The sample extract was filtered, diluted with phosphate buffered saline and applied to an ochratoxin immunoaffinity column. The column was washed with water and the ochratoxin A was eluted with methanol. The solvent was then evaporated an the residue re-dissolved in HPLC solvent. Following injection of this solution on a reverse phase HPLC, ochratoxin A was detected by fluorescence detector. Eight samples of low level naturally contaminated barley and two samples of blank barley were sent, along with ampoules of ochratoxin A calibrant and spiking solutions, to 17 laboratories in 13 different European countries. Test portions of samples were spiked at levels of 4ng/g and recoveries ranged from 65% to 113%. Based on results from spiked samples as well as naturally contaminated samples the relative standard deviation for repeatability ranged from 4% to 24% and the relative standard deviation for reproducibility ranged from 12% to 33%. The method showed acceptable within laboratory and between-laboratory precision, as evidenced by HORRAT ratios, at the low level of determination for ochratoxin A in barley.
Bibliographic Reference: EUR 18594 EN, (1999) 43pp.
Availability: Available free of charge from Documentation Service DG XII
ISBN: ISBN 92-828-2243-5
Record Number: 199910996 / Last updated on: 1999-07-23
Original language: en
Available languages: en