title: Inter-laboratory comparison study on measuring semi-volatile organic chemicals in standards and air samples.
abstract: Measurements of semi-volatile organic chemicals (SVOCs) were compared among 21 laboratories from 7 countries through the analysis of standards, a blind sample, an air extract, and an atmospheric dust sample. Measurement accuracy strongly depended on analytes, laboratories, and types of standards and samples. Intra-laboratory precision was generally good with relative standard deviations (RSDs) of triplicate injections <10% and with median differences of duplicate samples between 2.1 and 22%. Inter-laboratory variability, measured by RSDs of all measurements, was in the range of 2.8-58% in analyzing standards, and 6.9-190% in analyzing blind sample and air extract. Inter-laboratory precision was poorer when samples were subject to cleanup processes, or when SVOCs were quantified at low concentrations. In general, inter-laboratory differences up to a factor of 2 can be expected to analyze atmospheric SVOCs. When comparing air measurements from different laboratories, caution should be exercised if the data variability is less than the inter-laboratory differences.
authors.affiliation: Air Quality Research Division, Science and Technology Branch, Environment Canada, Toronto, Ontario, Canada. yushan.su@ec.gc.ca
authors.forename: Yushan
authors.initials: Y
authors.lastname: Su
authors.forename: Hayley
authors.initials: H
authors.lastname: Hung
mesh_terms: D000393:Air Pollutants / Q000032:analysis* / Q000592:standards; D002623:Chemistry Techniques, Analytical / Q000592:standards; D004391:Dust / Q000032:analysis; D007753:Laboratories / Q000706:statistics & numerical data; D012015:Reference Standards; D015203:Reproducibility of Results; D055549:Volatile Organic Compounds / Q000032:analysis* / Q000592:standards
chemical_list: D000393:Air Pollutants; D004391:Dust; D055549:Volatile Organic Compounds