Comparison of ISO-GUM and Monte Carlo methods for the evaluation of measurement uncertainty: Application to direct cadmium measurement in water by GFAAS

摘要: The propagation stage of uncertainty evaluation, known as the distributions, is in most cases approached by GUM (Guide to Expression Uncertainty Measurement) framework which based on law assigned various input quantities and characterization measurand (output quantity) a Gaussian or t-distribution. Recently, Supplement ISO-GUM was prepared JCGM (Joint Committee for Guides Metrology). This Guide gives guidance propagating probability distributions through numerical simulation (Monte Carlo Method) determining distribution measurand. In present work two approaches were used estimate direct determination cadmium water graphite furnace atomic absorption spectrometry (GFAAS). expanded results (at 95% confidence levels) obtained with Framework Monte Method at concentration level 3.01 μg/L ±0.20 ±0.18 μg/L, respectively. Thus, slightly overestimates overall 10%. Even after taking into account additional sources that considers negligible, again same result (±0.18 μg/L). main source this difference approximation estimating standard calibration curve produced least squares regression. Although proves be adequate particular case, generally has features avoid assumptions limitations Framework.