Screening for chloramphenicol residues in the tissues and fluids of treated cattle by the four plate test, Charm II radioimmunoassay and Ridascreen CAP-Glucuronid enzyme immunoassay†

Abstract

The administration of chloramphenicol (CAP) is banned in food animals in the European Union (EU). It is, therefore, important to have adequate screening methods to determine if residues of CAP and its major metabolite, chloramphenicol-glucuronide (CAP-Gluc), are present in samples taken for monitoring purposes. Six castrated male cattle were treated with a single intramuscular injection of 10 mg kg-1 CAP. Animals were sampled once daily for urine and were slaughtered at 3 and 6 d post-injection. Samples of bile, kidney, liver and diaphragmatic muscle were removed at slaughter. All matrices were analysed using the four plate test (FPT) bioassay, the Charm II radioimmunoassay and a Ridascreen CAP-Glucuronid competitive enzyme immunoassay (EIA). The FPT detected CAP residues in urine samples taken up to 2 d post-treatment. The Charm assay detected CAP in the urine for up to 4 d post-treatment. The EIA detected CAP throughout the 6 d sampling period. Samples of bile were positive by both the EIA and the Charm assay at day 3 and day 6. No zones of inhibition were obtained using the FPT in bile or diaphragm either with or without sample pre-treatment with beta-glucuronidase. However, the kidney and the liver from one animal killed at day 6 gave larger zones of inhibition after treatment with beta-glucuronidase, indicating the presence of CAP. The kidneys of all treated animals slaughtered at day 3 were positive by both the EIA and the Charm assay but none of the kidneys at day 6 tested positive by either method. Owing to technical difficulties, the Charm assay was not suitable for the analysis of liver. The EIA failed to detect CAP in the liver of any treated animal. It is concluded that urine appears to be the best matrix for screening purposes. The sensitivity of the FPT is inadequate for the determination of CAP residues were minimal withdrawal periods have been observed. The Charm assay and the EIA were suitable for the detection of both CAP and CAP-Gluc in tissues and body fluids for longer periods post-administration. The EIA was more sensitive for the determination of low concentrations of CAP and its metabolite.

Rapid determination of chloramphenicol and its glucuronide in food products by liquid chromatography–electrospray negative ionization tandem mass spectrometry

“…The methods applied for CAP may be divided into two groups: preliminary screening done by immunoassay [5][6][7] and confirmatory methods, based on gas chromatographymass spectrometry [7,8], or liquid chromatography-mass spectrometry.…”

Analysis of chloramphenicol in honeys of different geographical origin by liquid chromatography coupled to electrospray ionization tandem mass spectrometry

“…Different analytical methods have been developed to determine CAP in food, including radio and enzyme immunoassay (Arnold and Somogyi 1985, Charm and Chi 1988, Sheth and Sporns 1990, Van De Water and Haagsma 1991, Lynas et al 1998, Kolosova et al 2000, Gaudin and Maris 2001, gas chromatography (GC) (Weber 1990, Pfenning et al 2000, highperformance liquid chromatography (HPLC) (Jurgens 1982, Keukens et al 1986, Long et al 1990, Smedley and Weber 1990, Samouris et al 1993, Ramos et al 1994, Chevalier et al 1995, Hummert et al 1995, Perez et al 2002 and negative chemical ionization gas chromatography coupled to mass spectrometry (GC-MS-NCI) (van der Heeft et al 1991, Kijak 1994.…”

Development of a Biosensor-based Immunoassay for Screening of Chloramphenicol Residues in Milk

“…It is obviously negligible in milk because no conjugated CAP has been observed in this matrix, but it would be of primary importance in urine or bile because it is the main metabolite of chloramphenicol. 90% of CAP is excreted in urine and bile as a glucuronide conjugate, a microbiologically inactive metabolite (Lynas et al, 1998). Moreover, urine and bile are easy to collect compared to muscle or kidney.…”