Estimation of measurement uncertainty of pesticides, polychlorinated biphenyls and polyaromatic hydrocarbons in sediments by using gas chromatography–mass spectrometry

[Display omitted] ► We report an evaluation of uncertainty associated to analysis of POPs in sediments. ► We give useful and easy to follow guidance to calculate uncertainty. ► Evaluation of uncertainty is essential in environmental analysis. ► Uncertainty derived of calibration is the main contribution. ► We present strategies for diminish uncertainty. The evaluation of the uncertainty associated to analytical methods is essential in order to demonstrate quality of a result. However, there is often lack of information about uncertainty of methods to estimate persistent organic pollutants concentration in complex matrix. Current work has thoroughly evaluated uncertainty associated to quantification of several organochloride pesticides, PCBs and PAHs in sediments. A discussion of the main contributions to the overall uncertainty is reported, allowing authors to establish the accuracy of results and plan future improvements. Combined uncertainties ranged between 5–9% (pesticides), 4–7% (PCBs) and 5–10% (PAHs), being uncertainty derived of calibration the main contribution. Also, the analytical procedure was validated analysing a standard reference material (IAEA-408).