Comparison between top-down and bottom-up approaches in the estimation of measurement uncertainty in Bisphenol A analysis by HPLC-FLD

Measurement uncertainty is a metrological concept that characterizes distributions/variations that can make the measurement results logical and is linked to the result of the measurement. The measurement uncertainty of the method was estimated using two basic approaches (top-down and bottom-up approach). The top-down approach covers in-house validation data (trueness, repeatability and intra-lab reproducibility), while the bottom-up approach involves individual contributions to all uncertainty at each stage of the analysis/process. We estimated measurement uncertainty of BPA analysis by HPLC-FLD test according to JCGM GUM and EURACHEM-CITAC guidelines. The relative expanded uncertainties at the BPA concentration by the bottom-up approach and top-down approaches were ±3.2% and ±4.8% respectively (95% confidence interval, k=2). Thus, although it is seen that the results of the two approaches are different in chromatographic BPA analysis, it is concluded that the measurement uncertainty related to BPA analysis, especially in food analysis laboratories, can be determined by a simpler top-down approach.