Development of reference materials: Homogeneity and stability assessment based on the determination of chloramphenicol in fish muscle

The need for comparable and reliable analytical results is necessary for ensuring food safety and facilitating competitive local and global trade. The use of reference material (RM) is a key element for quality assurance. This study focused on developing a reference material for chloramphenicol in fish. Fish fillet, previously freeze-dried and fortified with chloramphenicol, was homogenized, and packed into individual units, producing 99 bottles with a net content of 4 g. Homogeneity was assessed through random stratified sampling, with measurements conducted via HPLC-PDA. Statistical analyses, including linear regression and Cochran's Test, revealed no significant trends or outliers. The prepared RM was sufficiently homogeneous based on ANOVA, with a relative standard uncertainty ( u bb ) of 1.12 %. A short-term stability assessment, employing linear regression, confirmed the RM's stability during transport at 4 °C for up to three weeks. Long-term stability study demonstrated that the RM was stable when stored for six months at −20 °C, with a relative standard uncertainty from instability ( u lts ) of 2.16 %. The developed RM holds a promising application in quality control and method validation, serving as a benchmark for accurate detection of chloramphenicol residues in fish muscle and potentially other similar matrices. Its application supports the Philippine agriculture sector by ensuring reliable testing laboratory results, aiding food safety decisions, and promoting product excellence, thereby enhancing fair and competitive worldwide trade.