Study of a new matrix certified reference material for accurate measurement of pefloxacin in fish meat powder

Abstract

Matrix certified reference materials (CRMs) have played a critical role in analytical method validation and assurance of reliable measurement results. A matrix CRM of pefloxacin in fish meat powder was newly studied and developed for fishery food quality and safety monitoring. The CRM candidates were prepared from incurred samples by procedures of freeze-drying, grounding, sieving, homogenizing, secondary freeze-drying, bottling and gamma-irradiating. Isotope dilution liquid chromatography tandem mass spectrometry (ID-LC/MS/MS) was established and applied to value assignment. The certified value was 45.3 μg/kg for mass fraction of pefloxacin in fish meat powder with expanded uncertainty of 3.7 μg/kg (k = 2, at a confidence of 95 %). Homogeneity, long-term stability of six months at −20 °C for storage, and short-term stability of nine days at 4 °C, 20 °C and 40 °C for transportation were investigated. In addition, uncertainty of the certified value originating from value assignment, homogeneity testing and stability monitoring were evaluated.