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9. Optimizing the balance between false positive and false negative error probabilities of confirmatory methods for the detection of veterinary drug residues†

Author

de Boer, Waldo J., primary, van der Voet, Hilko, additional, de Ruig, Wil G., additional, (Hans) van Rhijn, J. A., additional, Cooper, Kevin M., additional, Glenn Kennedy, D., additional, Patel, Raj K. P., additional, Porter, Sharon, additional, Reuvers, Thea, additional, Marcos, Victoria, additional, Muñoz, Patricia, additional, Bosch, Jaume, additional, Rodríguez, Pilar, additional, and Grases, Josep M., additional

Published
1999
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15. Production of CTC-containing porcine reference materials†

Author

McEvoy, John D. G., primary, Ferguson, Julie P., additional, Crooks, Steven R. H., additional, Glenn Kennedy, D., additional, van Ginkel, Leendert A., additional, Maghuin-Rogister, Guy, additional, Meyer, Heinrich H. D., additional, Pfaffl, Michael W., additional, Farrington, William H. H., additional, and Juhel-Gaugain, Murielle, additional

Published
1998
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22. Optimizing the balance between false positive and false negative error probabilities of confirmatory methods for the detection of veterinary drug residues†

Author

J. de Boer, Waldo, van der Voet, Hilko, G. de Ruig, Wil, A. (Hans) van Rhijn, J., M. Cooper, Kevin, Glenn Kennedy, D., K. P. Patel, Raj, Porter, Sharon, Reuvers, Thea, Marcos, Victoria, Muñoz, Patricia, Bosch, Jaume, Rodríguez, Pilar, and M. Grases, Josep

Abstract

GC-MS data on veterinary drug residues in bovine urine are used for controlling the illegal practice of fattening cattle. According to current detection criteria, peak patterns of preferably four ions should agree within 10 or 20% from a corresponding standard pattern. These criteria are rigid, rather arbitrary and do not match daily practice. A new model, based on multivariate modeling of log peak abundance ratios, provides a theoretical basis for the identification of analytes and optimizes the balance between the avoidance of false positives and false negatives. The performance of the model is demonstrated on data provided by five laboratories, each supplying GC-MS measurements on the detection of clenbuterol, dienestrol and 19β-nortestosterone in urine. The proposed model shows a better performance than confirmation by using the current criteria and provides a statistical basis for inspection criteria in terms of error probabilities.

Published
1999
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23. Production of CTC-containing porcine reference materials†

Author

D. G. McEvoy, John, P. Ferguson, Julie, R. H. Crooks, Steven, Glenn Kennedy, D., A. van Ginkel, Leendert, Maghuin-Rogister, Guy, H. D. Meyer, Heinrich, W. Pfaffl, Michael, H. H. Farrington, William, and Juhel-Gaugain, Murielle

Abstract

The European Commission (EC) established the Standards, Measurements and Testing programme for the preparation of Reference Materials (RMs) as an aid to harmonise testing for veterinary drug residues throughout the European Union (EU). The production of chlortetracycline (CTC)-free and CTC-incurred pig tissues as candidate RMs is described. High performance liquid chromatography (HPLC) with fluorescence detection of CTC and 4-epi-CTC was used for all tissue analyses. A pilot study revealed that incurred CTC residues were stable in pig kidney, liver and muscle lyophilised powders during storage for 10 weeks at –70, –20 and +37 °C, obviating the need for addition of a stabiliser (thimerosal). In the main study, 500 vials each of CTC-free and CTC-incurred kidney, liver and muscle were produced. Target concentrations in the CTC-incurred lyophilised tissue powders were 750–1500, 500–1000 and 300–600 µg kg–1 for kidney, liver and muscle, respectively. Following lyophilisation, the mean ± s concentrations of CTC in the incurred positive RMs were 1 315 ± 56.9, 765 ± 35.3 and 378 ± 16.8 µg kg–1 for kidney, liver and muscle respectively. Residual moisture in the RMs ranged from 1.6 ± 0.53% for muscle to 3.0 ± 0.50% for liver. Between-vial homogeneity for incurred powders was determined for 20 vials of each material, which had been removed at regular intervals during the filling process. Relative standard deviations (RSDs) for kidney, liver and muscle were 4.3, 4.6 and 4.4% respectively, being within the interassay RSD of the method and indicating that mixing was effective. Stability of powders stored at –18, 4, 20 and 37 °C was assessed over a period of 79 weeks. No measurable degradation occurred over this time period at any of the storage temperatures. It is concluded that these candidate RMs are homogenous, stable and are suitable for certification.

Published
1998
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25. The development and application of liquid chromatographic-mass spectrometric methods for the veterinary drugs carbadox and olaquindox

Author

Hutchinson, Michael John, Glenn Kennedy, D., and Young, Paul

Subjects
636.0895954
Abstract

The use of veterinary drugs and zootechnical feed additives has become widespread in modern agricultural practice. Each Member State of the European Union is required to monitor for residues of these compounds in animal tissue and animal products that are intended for human consumption. From 1st September, 1999, the use of the zootechnical feed additives, carbadox and olaquindox is not permitted within the European Union. An electrospray LC-MS-MS method for the confirmation of carbadox and olaquindox in meal is described. The method was developed for contamination level analysis of each drug in feed. An electrospray LC-MS-MS method for the carbadox marker residue in tissue, quinoxaline-2-carboxylic acid, is described. The method was validated over the range 3.0 - 300 pg kg"1, to reflect the range of concentrations measured in NI National Surveillance Scheme samples. The Decision Limit and Detection Capability are also described. This tissue method was applied to the pharmacokinetic study of pigs exposed to housing contaminated by carbadox treated animals. Tentative criteria are suggested for a method that enables National Authorities to discriminate between deliberate use and accidental exposure to contaminated housing. A dual electrospray LC-MS-MS method for the carbadox and olaquindox tissue marker residues, quinoxaline-2-carboxylic acid and methyl-3-(quinoxaline-2)-carboxylic acid, respectively, are presented. The method was validated over the range 3.0 - 150 pg kg"1, to reflect the range of possible concentrations to be measured in Northern Ireland National Surveillance Scheme samples. The Decision Limit and Detection Capability are also described. All the presented methods have been validated according to current European Union criteria for veterinary residue analysis (European Commission Decision 2002/657/EC). All the described methods are to be applied to the statutory analysis of samples taken in Northern Ireland.

Published
2004

26. Occurrence of alpha- and beta-nortestosterone residues in the urine of injured male cattle.

Author

Glenn Kennedy D, Desmond Shortt H, Crooks SR, Young PB, Price HJ, Smyth WG, and Hewitt SA

Subjects
Animal Husbandry, Animals, Cattle urine, Male, Meat Products, Wounds and Injuries urine, Anabolic Agents urine, Cattle injuries, Drug Residues analysis, Nandrolone urine, Wounds and Injuries veterinary
Abstract

The administration of anabolic steroids, for the purposes of growth promotion, to food-producing animals is banned in the EU. Among the compounds covered by this prohibition is ss-nortestosterone (beta-NT). This hormone is known to occur naturally in stallions and boars, and its main bovine metabolite, alpha-nortestosterone (alpha-NT), occurs naturally in pregnant cows and neonatal calves. However, neither compound is believed to occur naturally in male cattle. During 2006, the presence of alpha-NT and, on occasion, beta-NT was confirmed in male cattle (bulls and steers) slaughtered in Northern Ireland on welfare grounds, as a result of acute injury. Subsequent investigations revealed no evidence of abuse at any of the farms involved and revealed that the phenomenon also occurred in three other regions of the EU, in similarly injured animals. A hypothetical link to release of the adrenal steroid, dehydroepiandrosterone (DHEA), in response to the stress of the injury was tested. Following the intravenous administration of DHEA to two normal steers, beta-NT (but not alpha-NT) was confirmed in the urine of one steer. Thus, it may be concluded that both beta-NT and, by implication, alpha-NT can occur naturally in male cattle (or a specific cohort thereof) in contrast to previously accepted scientific knowledge.

Published
2009
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