Stability of organochlorine pesticides during storage in water and loaded SPE disks containing sediment.

With regard to the Water Framework Directive (WFD) and the required investigation of the whole water sample including suspended particulate matter (SPM), a storage stability study was conducted to determine the suitable storage time and conditions of 21 organochlorine pesticides (OCPs) spiked in water samples and pre-concentrated on solid-phase extraction disks (SPE disks). Furthermore, this work demonstrates the behaviour of three different certified sediment reference materials (CRMs) contaminated with OCPs in water samples as well as loaded on SPE disks under different temperature conditions and storage time periods. Extracts collected on SPE disks were stored for 3, 14 and 30 days at both 4 °C and -18 °C in darkness covered in (a) freezer bags and (b) aluminum foil.