title: Determination of polychlorinated biphenyls and organochlorine pesticides in small volumes of human blood by high-throughput on-line SPE-LVI-GC-HRMS.
abstract: A fully automated and robust method featuring on-line solid-phase extraction (SPE) and large volume injection (LVI) gas chromatographic (GC) high resolution mass spectrometry (HRMS) is used to determine polychlorinated biphenyls (PCBs) and organochlorine pesticides, such as penta- and hexachlorobenzene (PeCBz, HxCBz), hexachlorocyclohexane isomers (HCH) and 4,4'-dichlorodiphenyldichloroethene (a metabolite of dichlorodiphenyltrichloroethane (DDT)), with only 200μl of human blood, serum or plasma. After spiking the sample with (13)C-labeled internal standards and precipitating the proteins, the sample is passed through a 10mm×2.0mm ID SPE cartridge filled with C18 material that adsorbs the analytes. After washing and drying, the cartridge is extracted with hexane/dodecane (99/1, v/v); the extract is directly injected into a LVI where GC/HRMS analysis follows. The fully automated system utilizes a robotic autosampler and a modular SPE system including two high-pressure syringe pumps, an automatic SPE cartridge exchanger unit and 6 switchable valves. All sample preparation steps are performed within 20min during the GC run of a previous sample, limiting the throughput with only the GC runtime. The contents are quantified using the isotope dilution method. Due to laboratory air contamination problems, we achieved LOQs of 0.017 (PeCBz), 0.009 (HxCBz), 0.007 (HCH), 0.016 (DDE), while for the six indicator PCBs, we achieved values of 0.030 (PCB-28), 0.044 (PCB-52), 0.024 (PCB-101), 0.009 (PCB-138), 0.015 (PCB-153) and 0.008 (PCB-180)μg/l serum. Under clean laboratory air conditions, these values may be improved. This method is recommended when high throughput is desirable and/or only small amounts of material are available, such as during studies involving children.
authors.affiliation: Department of Hygiene, Social and Environmental Medicine, Ruhr-University Bochum, Universitätsstraße 150, D-44801 Bochum, Germany. Electronic address: wittsiepe@hygiene.rub.de.
authors.forename: Jürgen
authors.initials: J
authors.lastname: Wittsiepe
authors.affiliation: Instrumental Analytical Chemistry, University Duisburg-Essen, Universitätsstraße 5, D-45141 Essen, Germany.
authors.forename: Marco
authors.initials: M
authors.lastname: Nestola
authors.affiliation: Department of Hygiene, Social and Environmental Medicine, Ruhr-University Bochum, Universitätsstraße 150, D-44801 Bochum, Germany.
authors.forename: Matthias
authors.initials: M
authors.lastname: Kohne
authors.affiliation: Department of Analytical Chemistry, Ruhr-University Bochum, Universitätsstraße 150, D-44801 Bochum, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Zinn
authors.affiliation: Department of Hygiene, Social and Environmental Medicine, Ruhr-University Bochum, Universitätsstraße 150, D-44801 Bochum, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Wilhelm
mesh_terms: D004867:Equipment Design; D008401:Gas Chromatography-Mass Spectrometry / Q000191:economics / Q000295:instrumentation*; D057166:High-Throughput Screening Assays / Q000191:economics / Q000295:instrumentation*; D006801:Humans; D006843:Hydrocarbons, Chlorinated / Q000097:blood*; D057230:Limit of Detection; D010575:Pesticides / Q000097:blood*; D011078:Polychlorinated Biphenyls / Q000097:blood*; D052616:Solid Phase Extraction / Q000191:economics / Q000295:instrumentation*
chemical_list: D006843:Hydrocarbons, Chlorinated; D010575:Pesticides; D011078:Polychlorinated Biphenyls
keywords: Gas chromatography; Human blood; Large volume injection; Mass spectrometry; On-line solid phase extraction; Organochlorine pesticides; Polychlorinated biphenyls