Feasibility study for development of candidate reference material for food analysis: Chloramphenicol in milk powder

Reliable analytical results are necessary to ensure effective consumer protection and the use of certified reference material (CRM) is an important tool for quality assurance. The Brazilian Metrology Institute (Inmetro) studied the feasibility of the production of a candidate CRM of chloramphenicol (CAP) in milk. CAP is an antibiotic banned for treatment of food-producing animals. A minimum required performance limit (MRPL) for analytical methods of 0.3 μg kg−1 was set by the European Community for the detection of CAP residues in food matrices. Liquid chromatography with isotope dilution mass spectrometry (LC-IDMS) was employed for CAP determination and water content was measured by Karl Fischer coulometric titration. The feasibility study showed milk powder processed with both spray dryer and lyophilization lead to the best results, showing good degree of inhomogeneity for CAP residues (5.0%) and for water content (3.0%), therefore demonstrating that the production of this candidate CRM was feasible.