Pilot study of labelling bovine muscle tissue with 14C

A pilot study has been performed to assess the feasibility of labelling bovine muscle tissue with 14C, in order to produce material suitable for intercomparison exercises. Approximately 1 kg of tissue was prepared by grinding, blending, labelling with 14C-methylated bovine haemoglobin and thoroughly mixing by repeated blending. The product was sealed in cans and sterilized to preserve it. Portions of raw material were dried to test the homogeneity of moisture content. Homogeneity of 14C in the natural and labelled materials was tested by analyzing sub-samples of 2-3 g in weight of the freeze-dried materials. The 14C content was determined by combusting and collecting the CO2 for liquid scintillation counting. The material was found to be homogeneous to the extent of 2-4% (R.S.D.), which is comparable with the R.S.D. of the 14C measurements. The 14C concentration in the labelled material was 8190 +/- 220 Bq.kg-1 of carbon. It was concluded that bovine muscle prepared in this manner would be suitable for intercomparison exercises. The 14C level in unlabelled tissue was found to be 260 +/- 7 Bq.kg-1 of carbon, which is similar to the level of 14C previously determined in milk and both are consistent with levels measured in vegetation in Eastern Ontario.