title: Analysis of PCDD/Fs and dioxin-like PCBs in atmospheric deposition samples from the Flemish measurement network: Optimization and validation of a new CALUX bioassay method.
abstract: Since the CALUX (Chemically Activated LUciferase gene eXpression) bioassay is a fast, sensitive and inexpensive tool for the analysis of a high number of samples, validation of new methods is urgently needed. In this study, a new method for the analysis of PCDD/Fs and dioxin-like PCBs in atmospheric deposition samples with the CALUX bioassay was developed, optimized and validated. The method consists of 4 steps: filtration, extraction, clean up and bioassay analysis. To avoid the use of large amounts of toxic solvents, new techniques were used for filtration and extraction: a C18 filter was used instead of a liquid/liquid extraction and an Accelerated Solvent Extractor (ASE) was used instead of the traditional soxhlet extraction. After pre-oxidation of the sample extract, clean up was done using a multi-layer silica gel column coupled to a carbon column. The PCDD/F and PCB fractions were finally analyzed with the H1L7.5c1 and/or the H1L6.1c3 mouse hepatoma cell lines. The limit of quantification was 1.4pg CALUX-BEQm(-2)d(-1) for the PCBs and 5.6pgCALUX-BEQm(-2)d(-1) for the PCDD/Fs, when using the new sensitive H1L7.5c1 cell line. The GC-HRMS recovery for all PCDD/F congeners was between 55% and 112%, with a mean recovery of 90%. CALUX recoveries of spiked procedural blanks were between the accepted ranges of 80-120%. Repeatability and reproducibility were satisfactory and no interferences from metals were detected. The first results from the Flemish measurement program showed good correlation between CALUX and GC-HRMS.
authors.affiliation: Vrije Universiteit Brussel, Department of Analytical and Environmental Chemistry (ANCH), Pleinlaan 2, 1050 Brussels, Belgium. kim.croes@vub.ac.be
authors.forename: K
authors.initials: K
authors.lastname: Croes
authors.forename: K
authors.initials: K
authors.lastname: Van Langenhove
authors.forename: M
authors.initials: M
authors.lastname: Elskens
authors.forename: M
authors.initials: M
authors.lastname: Desmedt
authors.forename: E
authors.initials: E
authors.lastname: Roekens
authors.forename: A
authors.initials: A
authors.lastname: Kotz
authors.forename: M S
authors.initials: MS
authors.lastname: Denison
authors.forename: W
authors.initials: W
authors.lastname: Baeyens
mesh_terms: D001272:Atmosphere / Q000737:chemistry; D001530:Belgium; D001572:Benzofurans / Q000032:analysis*; D001681:Biological Assay / Q000379:methods*; D000072338:Dibenzofurans, Polychlorinated; D004147:Dioxins / Q000032:analysis*; D004784:Environmental Monitoring / Q000379:methods*; D008401:Gas Chromatography-Mass Spectrometry; D011078:Polychlorinated Biphenyls / Q000032:analysis*; D000072317:Polychlorinated Dibenzodioxins / Q000031:analogs & derivatives* / Q000032:analysis
chemical_list: D001572:Benzofurans; D000072338:Dibenzofurans, Polychlorinated; D004147:Dioxins; D000072317:Polychlorinated Dibenzodioxins; D011078:Polychlorinated Biphenyls