DEVELOPMENT OF BOVINE MUSCLE, LIVER AND URINE REFERENCE MATERIALS FORZERANOL - PREPARATION, HOMOGENEITY AND STABILITY

Samples of bovine muscle, liver and urine, zeranol-free (RM 508, RM 50 9 and RM 510, respectively) and zeranol-containing (RM 511, RM 512 and RM 513, respectively) were prepared and tested as candidate reference materials. Preliminary studies on achievement of target zeranol conte nt, intercomparison of analytical methods (HPLC-RIA and GC-MS) and eff ects of lyophilisation and irradiation on zeranol content are describe d. The preparation of the materials and testing for homogeneity and st ability of zeranol in the materials are discussed. The coefficients of variation for zeranol determinations for between-vial homogeneity (4. 0%, 4.4% and 4.6% for muscle, liver and urine, respectively) are simil ar to those for the analytical method (4.0%, 7.3% and 6.8% for muscle, liver and urine, respectively) indicating that the materials are homo geneous. Stability data over a 12-month storage period at temperatures ranging from -18 degrees C to + 37 degrees C indicate that the materi als are sufficiently stable for use as reference materials.