Radioimmunoassay of the anabolic agent zeranol. II. Zeranol concentrations in urine of sheep and cattle implanted with zeranol (Ralgro)

Abstract

A radioimmunoassay for zeranol has been validated and used to measure the concentration of zeranol in the urine of sheep and cattle treated with zeranol (Ralgro). The assay uses an antibody raised against zeranol-16-carboxy-propyl ether conjugated to human serum albumin. In sheep and cattle urine the limits of detection were approximately 2 ng/ml and 2.5 ng/ml, respectively. In two trials 13 sheep were implanted with 12 mg zeranol at the base of the ear. The mean maximum concentrations of zeranol observed in urine were 45 ng/ml (Trial I) on day 35 and 90 ng/ml (Trial II) on day 56, and had declined to 26 ng/ml 42 days after implantation (Trial I) and 11.7 ng/ml 70 days after implantation (Trial II). In four cattle implanted with 36 mg zeranol the concentrations of zeranol in urine reached a mean maximum concentration of 13.5 ng/ml 22 days after implantation and had declined to 2.9 ng/ml 69 days after implantation.

Development and evaluation of immunoassay for zeranol in bovine urine

“…Anti-ZER antiserum was developed by immunizing New Zealand white rabbits with the conjugate of carboxypropyl ether derivatives at C-16 (16-CPE) of zeranol and the immunogenic carrier protein bovine serum albumin (BSA) (Liu et al, 2006;Dioxn and Russell, 1983). The coated antigen ZERovalbumin (ZER-OVA) was synthesized using the mixed anhydride method (Chen et al, 1990).…”

“…Various techniques have been developed for the detection of zeranol including gas chromatography/ mass spectrometry (GC-MS) (Dickson et al, 2003), high performance liquid chromatography/mass spectrometry (HPLC-MS) (Sorensen and Elbaek, 2005;Fang et al, 2002;Taguchi et al, 2001;Horie and Nakazawa, 2000) and immunoassay (Dioxn and Russell, 1983;Daniel and Robert, 1983;Jansen et al, 1986). Immunoassay is a good alternative to instrumental analysis for the determination of veterinary residues in various samples.…”

Possible Naturally Occurring Zeranol in Bovine Bile in Northern Ireland

“…All samples were assayed using an in-house radioimmunoassay for zeranol, using a polyclonal antibody similar to that described by DIXON and RUSSELL (1983). The antibody, which was raised against a conjugate between zeranol-16-carboxypropyl ether and human serum albumin, cross-reacted with Fusarzwrn toxins as shown in Table 1.…”

Development and validation of dry reagent time-resolved fluoroimmunoassays for zeranol and α -zearalenol to assist in distinguishing zeranol abuse from Fusarium spp. toxin contamination in bovine urine

“…Carboxypropylether derivative at C16 of ¬-zearalenol was prepared as described by Dixon and Russell (1983). This 16-CPE derivative was conjugated to the immunogenic carrier protein bovine thyroglobulin (BTG) using the acid anhydride method of Erlanger et al (1967).…”