Macedonian Veterinary Review (Nov 2009)
Comparison of two different analytical methods for determination of aflatoxins in feed
Abstract
Liquid chromatography - fluorescence detector and fluorometry (fluorescence spectrometry) with previous immunoaffinity column clean-up, are two methods that are compared in order to evaluate their performances in determination of total aflatoxins content in feed. Method validation was established, linearity of the methods was checked, and a good coefficient of correlation was found for bought methods (0,9994 and 0,978 respectively). The limits of detection were 0,003 ng/ml (average for HPLC-FD method) and 0,12 ng/ml for fluorometry. The accuracy of the methods was determined using reference materials with known concentration and spiked aflatoxins free samples. The recoveries were found to be 85,82% (average for HPLC-FD method) and 56,75%, for fluorometry. Twenty feed concentrates for bullock and 20 feed concentrates for swine, were analyzed parallel with bought methods. The results are in correlation only in higher concentration range. For lower concentration range (below 1,0 μg/kg) fluorometry shows limited sensitivity and selectivity. It was found that it is applicable only as a screening method for the prediction of aflatoxins. HPLC-FD method remains a method of choice for the analyst in order to achieved accurate and reliable results.
