Quinoxaline‐2‐carboxylic acid (QCA) in swine liver and muscle

Abstract

The concentration of quinoxaline-2-carboxylic acid (QCA) determined by HPLC after alkaline hydrolysis of liver and muscle of swine, ranged from < 3 ng/g to 45.3 ng/g in liver, and from < 3 ng/g to 10.8 ng/g in muscle samples. After the 77th day of therapy QCA was found in samples of liver (9.7 ng/g). Recoveries obtained for both liver and muscle were 70% at 5 ng/g, 77% and 75% respectively at 10 ng/g, and 90% for both liver and muscle at 30 ng/g. This experiment was performed within the frame of the National Monitoring Programme of Residues in Animal Tissues in the Republic of Croatia.

Development and validation of an improved method for confirmation of the carbadox metabolite, quinoxaline-2-carboxylic acid, in porcine liver using LC-electrospray MS-MS according to revised EU criteria for veterinary drug residue analysis

“…Methods using high performance liquid chromatography (HPLC) with UV detection, [6][7][8][9] and gas chromatography-mass spectrometry (GC-MS) 10,11 have been published describing the analysis of QCA in tissue. The European Union is revising the criteria that must be applied in both the screening and confirmation of veterinary drug residues in animals of food origin, 12 replacing those currently used.…”

Confirmation of carbadox and olaquindox metabolites in porcine liver using liquid chromatography–electrospray, tandem mass spectrometry

“…This paper describes a method for the confirmation of both the carbadox metabolite QCA and the olaquindox metabolite MQCA in porcine liver that meets the new technical criteria. The described method also offers a considerable advantage in terms of turnaround time over previously published methods [7][8][9][10] and in the numbers of samples that can be processed by a skilled analyst per batch [13].…”

“…To ensure confidence in the meat industry and to enforce the ban of both compounds, tissues of food-producing animals must be guaranteed free of such residues within the EU. Methods such as high performance liquid chromatography (HPLC) with UV detection [7,8] and gas chromatography-mass spectrometry (GC-MS) [9,10] have been published, describing the analysis of QCA in tissue. No methods have yet been published describing the analysis of MQCA, Published methods describe only the detection of olaquindox or its desoxy metabolites in tissue [11,12].…”

Development and validation of an indirect competitive enzyme-linked immunosorbent assay for monitoring quinoxaline-2-carboxylic acid in the edible tissues of animals

“…In recent years several methods, such as HPLC (Binnendijk et al 1991;Rose et al 1995;Rutalj et al 1996;Wu et al 2007), GC-MS (Lynch et al 1991;Sin et al 2004) and LC-MS (Hutchinson et al 2002(Hutchinson et al , 2005Horie and Murayama 2004), have been used to detect QCA content. Although these methods are sensitive and specific, they are very expensive and not suitable for screening a large number of samples.…”