Rapid, Low Cost Thin-Layer Chromatographic Screening Method for the Detection of Ochratoxin A in Green Coffee at a Control Level of 10 μg/kg
- 15 December 2001
- journal article
- Published by American Chemical Society (ACS) in Journal of Agricultural and Food Chemistry
- Vol. 50 (2), 243-247
- https://doi.org/10.1021/jf010867w
Abstract
A thin-layer chromatographic (TLC) screening method was developed for the detection of ochratoxin A (OTA) in green coffee at a control level of 10 microg/kg. The method is based on extraction of OTA with a mixture of phosphoric acid and dichloromethane, purification by liquid-liquid partition into sodium hydrogen carbonate, separation by normal-phase TLC, and detection by visual estimation of fluorescence intensity under a UV lamp at 366 nm. The method was validated by performing replicate analyses of uncontaminated green coffee material spiked at 3 different levels of OTA (5, 10, and 20 microg/kg), and also by comparing results obtained on a series of test trial green coffees naturally contaminated with OTA (range 0.2 to 136.7 microg/kg) with those measured by a quantitative immunoaffinity/HPLC method. The agreement between the two methods was excellent, and neither false positive nor false negative results were recorded. This screening method is rapid, simple, robust, and very cheap, which makes it particularly well adapted for implementation in coffee-producing countries.This publication has 12 references indexed in Scilit:
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