Development of clenbuterol reference materials: lyophilized bovine eye samples free of clenbuterol (CRM 673) and containing clenbuterol (CRM 674). Part 1. Preparation, homogeneity and stability

摘要: Within the EU Standards, Measurement and Testing Program (SMT) two clenbuterol reference materi- als (RMs) were developed. Since readily ac- cumulates is slowly depleted from pigmented tissues such as retina, homogenized eye liquid content most sensitive tissue for detection of mis- use. Therefore, both RMs produced bovine matrix: a negative control - RM 673 ref- erence material, free (<0.50 µg/kg matrix) positive 674 material contain- ing (~10 matrix). Eyes sam- pled 103 German Simmental cattle inner liq- uid was to wet (HLC). This pool divided into sub-pools, one which spiked with final concentration 10 µg clen- buterol/kg HLC. Of each exactly 2.0±0.01 g (±0.5%) portions weighed 790 containers. Lyophiliza- tion 1580 containers performed in batch. Parameters filling containers, dry matter con- tent, residual moisture accordance requirements. A three-year stability study homo- geneity studies at various storage temperatures (-60 °C, -20 +4 +20 +37 °C) performed. Low variation observed within all homogeneity studies, proving that homogeneous this independent temperature time. In measured concentrations remained constant under limit 0.15±0.01 equivalent/kg HLC (n=110) also 11.21±0.15 clenbuterol/kg (n=150; duplicates). These demonstrate clenbuterol- containing clenbuterol-free matrix can be successfully produced. Based on results de- scribed above, it concluded may suit- able candidates certification.