Study of a new matrix certified reference material for accurate measurement of florfenicol in prawn meat powder

A new matrix certified reference material (CRM) of florfenicol in prawn meat powder [GBW(E)100638] was developed for validation of analytical method and assurance of measurement quality in the routine monitoring of prawn food safety. The incurred prawn materials were freeze-dried, ground, sieved, homogenized, bottled and gamma-irradiated to prepare the CRM candidates. For characterization of the CRM, isotope dilution coupled with liquid chromatography tandem mass spectrometry as a reliable and accurate method was studied and employed by all participants in co-laboratory value assignment program. The certified value with expanded uncertainty (k = 2, at a confidence of 95%) was 11.8 mu g/kg +/- 1.9 mu g/kg for florfenicol in prawn meat powder. Homogeneity, long-term stability of fifteen months at -20 degrees C for storage, and short-term stability of nine days at 4 degrees C, 20 degrees C and 40 degrees C for transportation and use were examined. In addition, uncertainties originating from characterization, inhomogeneity and instability were assessed.