title: Influence of the drying step within disk-based solid-phase extraction both on the recovery and the limit of quantification of organochlorine pesticides in surface waters including suspended particulate matter.
abstract: In this study, 21 organochlorine pesticides (OCPs) were determined based on sample preparation using solid-phase extraction disks (SPE disks) coupled with programmable temperature vaporizer (PTV)-large-volume injection gas-chromatography mass spectrometry (LVI-GC-MS). The work includes a comprehensive testing scheme on the suitability of the method for routine analysis of surface and drinking water including suspended particulate matter (SPM) with regard to requirements derived from the European Water Framework Directive (WFD, Directive 2000/60/EC). SPM is an important reservoir for OCPs, which contributes to the transport of these compounds in the aquatic environment. To achieve the detection limits required by the WFD, a high pre-concentration factor during sample preparation is necessary, which was achieved by disk SPE in this study. The performance of disk SPE is strongly influenced by the drying step, which could be significantly improved by effective elimination of the residual water by combination of a high vacuum pump and a low humidity atmosphere. Detection limits of the WFD in the ng/L range were achieved by large volume injection of 100μL sample extract. The recoveries ranged from 82% to 117% with an RSD smaller than 13%. The applicability of this method to natural samples was tested for instrumental qualification and system suitability evaluation. Successful participation in an interlaboratory comparison proved the suitability of the method for routine analysis.
authors.affiliation: IWW Water Centre, Moritzstraße 26, 45476 Mülheim an der Ruhr, Germany; University of Duisburg-Essen, Instrumental Analytical Chemistry, Universitätsstraße 2, 45141 Essen, Germany. Electronic address: a.guenter@iww-online.de.
authors.forename: Anastasia
authors.initials: A
authors.lastname: Günter
authors.affiliation: IWW Water Centre, Moritzstraße 26, 45476 Mülheim an der Ruhr, Germany. Electronic address: p.balsaa@iww-online.de.
authors.forename: Peter
authors.initials: P
authors.lastname: Balsaa
authors.affiliation: IWW Water Centre, Moritzstraße 26, 45476 Mülheim an der Ruhr, Germany. Electronic address: friedrich.werres@t-online.de.
authors.forename: Friedrich
authors.initials: F
authors.lastname: Werres
authors.affiliation: IWW Water Centre, Moritzstraße 26, 45476 Mülheim an der Ruhr, Germany; University of Duisburg-Essen, Instrumental Analytical Chemistry, Universitätsstraße 2, 45141 Essen, Germany. Electronic address: torsten.schmidt@uni-due.de.
authors.forename: Torsten C
authors.initials: TC
authors.lastname: Schmidt
mesh_terms: D003890:Desiccation; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D006843:Hydrocarbons, Chlorinated / Q000032:analysis*; D057230:Limit of Detection; D052638:Particulate Matter / Q000032:analysis*; D010575:Pesticides / Q000032:analysis*; D052616:Solid Phase Extraction / Q000379:methods*; D014867:Water / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D006843:Hydrocarbons, Chlorinated; D052638:Particulate Matter; D010575:Pesticides; D014874:Water Pollutants, Chemical; D014867:Water
keywords: Gas chromatography–mass spectrometry; Solid phase extraction disk; Surface water; Suspended particular matter; Water framework directive