Chloramphenicol immunoassay

In order to prevent veterinary dmgs from being transported to the human food chain, radioisotopic immunoassays were developed to monitor veterinary antibiotics such as penicillin and chloramphenicol [56-75-7] C22H22Cl2N20, in meat, milk, and eggs (qv) (see ANTIBIOTICS Meatproducts Milk AND MILKPRODUCTS). 

Certain drugs such as chloramphenicol require additional tests for their detection and quantification in meat tissues. The Competitive Enzyme Labeled Immunoassay for Chloramphenicol (CELIA) was developed and is used by FSIS laboratories to detect and quantify this drug in the meat supply chloramphenicol is not approved for use in food animals. CELIA detects 5 ppb chloramphenicol in tissue extracts. 

Despite the fact that the preparation of chloramphenicol-specific antibodies was reported as early as in 1966 (36), it was 1984 before the first immunoassay was published for the determination of chloramphenicol residues in swine muscle, eggs, and milk (37). This first-published method was a radioimmunoassay that required an extraction procedure and special laboratory facilities to attain a quantification limit of 1 ppb. Employed polyclonal antibodies showed insignificant crossreactivity with structurally related compounds, except that thiamphenicol that did not interfere with the analysis. However, cross-reactivity was significant for metabolites deviating from the parent compound in the acyl side chain. 

An indirect enzyme immunoassay suitable for the determination of chloramphenicol and its glucuronide was developed for the analysis of urine, milk, tissue, and eggs as well (48). In this assay, chloramphenicol succinate was coupled to both bovine serum albumin and horseradish peroxidase by a mixed anhydride procedure. Unlike tissue and egg samples, urine and defatted milk could be directly analyzed, but when an ethyl acetate extraction was employed in milk analysis, the limit of detection was lowered at least 10 times. 

Immunochemical methods that utilize radioisotopic labeling can detect the use of anabolic sex hormones that increase the growth in meat animals. Stilbene [588-59-0], C14H12, trenbolone [10161-33-8], and zeranol [55331-29-8], C18H2605, can be successfully monitored by these immunoassay techniques (45). In order to prevent veterinary dmgs from being transported to the human food chain, radioisotopic immunoassays were developed to monitor veterinary antibiotics such as penicillin and chloramphenicol [56-75-7], C H CyX C, in meat, milk, and eggs (qv) (see Antibiotics Meat products Milk AND MILKPRODUCTS). 

Procedures for the determination of chloramphenicol concentrations in blood serum include HPLC and immunoassay. Methods for chloramphenicol determination must be able to differentiate between the prodrug forms, chloramphenicol palmitate or succinate, and their active metabolite, chloramphenicol. (An HPLC method for measuring chloramphenicol is included on this book s accompanying Evolve site, found at http //evoIve. elsevier.com/Tietz/textbook/.)... 

Barker, S.A. Long, A.R. Preparation of milk samples for immunoassay and liquid chromatographic screening using matrix solid-phase dispersion. J.AOAC Int, 1994, 77, 848-854 [MSPD infant formula also albendazole, chloramphenicol, chlorsulon, chlortetracycline, fenbendazole, furazolidone, mebendazole, oxfendazole, oxytetracycUne, sulfadiazine, sulfadimethoxine, sulfamerazine, sulfa-... 

Gaudin V, Maris P, Development of a biosensor-based immunoassay for screening of chloramphenicol residues in milk, FoodAgric. Immunol. 2001 13 77-86. 

Maertlbauer, E. Terplan, G. Enzyme immunoassay for the detection of chloramphenicol in milk. Arch. Lebensntittelhyg., 38 3-7. 1987. German. 

Enzyme immunoassays, in a card-test format, are also used for screening carcasses by testing of urine for specific antimicrobial residues such as sulfadimidine and chloramphenicol. The sol particle immunoassay uses adsorption of specific antibodies to dyed colloidal particles (e.g., carbon) as a mechanism for making directly visible the presence of residues (i.e., antigen) in the sample. A lateral flow membrane device is used to identify residue-positive samples through the absence of color formation at the test capture zone (Figure 5). 

---