RT null T1 Guidelines for the Sampling and Pre-treatment of National Samples within the UNEP Capacity Building Project 2016-2019 A2 de Boer, Jacob A2 Fiedler, Heidelore K1 persistent organic pollutant YR 2018 FD 2018 LK https://wedocs.unep.org/handle/20.500.11822/26206 UL https://wedocs.unep.org/handle/20.500.11822/26206 DS UN Environment Document Repository RD Sep 16, 2026