Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer reviewed journal
Publication Acceptance Date: 1/12/1996
Publication Date: N/A
Citation: Interpretive Summary: This study describes the development of a simple, rapid, immunoassay for detecting the veterinary drug furosemide. A quick screening method to detect this residue in meat and in milk is presently unavailable. The immunoassay described is based on an anti-furosemide monoclonal antibody and is capable of detecting this drug in the low part-per-billion range in milk. Furosemide is used in dairy cattle to treat swelling following calfing. Milk from animals infected with this drug were analyzed with the immunoassay. These results suggested that the drug rapidly disappeared from the milk. Furthermore, the immunoassay is easier, faster, and more sensitive than the traditional chemical assay that relies on a high-performance liquid chromatography system. The simplicity and low cost of the immunoassay makes it a useful tool for producers for the management of their animals and for agencies interested in monitoring for compliance with applicable regulations.
Technical Abstract: Furosemide is a potent diuretic drug used in both human and veterinary medicine. High performance liquid chromatographic methods (HPLC) were developed to detect furosemide in blood and urine samples. Recently, immunoassay kits have appeared to measure furosemide, these were developed for the race horse industry where furosemide is used to treat epistaxis. In dairy, cattle, furosemide is used for treatment of physiological parturient edema and there is a 48 h withdrawal period before milk from treated animals can be used. We report here the development of a monoclonal antibody-based enzyme-linked immunosorbent assay (ELISA) for detecting furosemide in milk. In addition, we report on the development of an HPLC method for detection in serum and blood. Unlike the HPLC method, no sample preparation is necessary for the ELISA. Raw milk is added directly into the assay, or if needed it is diluted with assay buffer. The immunoassay had a lower limit of quantification of 2 ppb and a lower limit of detection of approximately 0.5 ppb. Good correlation's were observed between the HPLC and ELISA methods when samples with both incurred and spiked furosemide residues were analyzed.