title: Quantification of PCDD/Fs and dioxin-like PCBs in small amounts of human serum using the sensitive H1L7.5c1 mouse hepatoma cell line: optimization and analysis of human serum samples from adolescents of the Flemish human biomonitoring program FLEHS II.
abstract: Since the CALUX (Chemically Activated LUciferase gene eXpression) bioassay is a fast and inexpensive tool for the throughput analysis of dioxin-like compounds in a large number of samples and requires only small sample volumes, the use of this technique in human biomonitoring programs provides a good alternative to GC-HRMS. In this study, a method for the separate analysis of PCDD/Fs and dioxin-like PCBs (dl-PCBs) in human serum with the new sensitive H1L7.5c1 mouse hepatoma cell line was optimized. Sample dilution factors of 5 and 2.4 were selected for routine analysis of respectively the PCDD/Fs and dl-PCBs. The validation studies showed that repeatability and within-lab reproducibility for the quality control (QC) standard were within the in-house criteria. A long-term within-lab reproducibility of 25% for the PCDD/F fraction and 41% for the dl-PCB fraction for the analysis of pooled serum samples, expressed as pg BEQ/g fat, was determined. CALUX recoveries of the spiked procedural blanks were within the acceptable in-house limits of 80-120% for both fractions and the LOQ was 30.3 pg BEQ/g fat for the PCDD/Fs and 14.5 pg BEQ/g fat for the dl-PCBs. The GC-HRMS recovery of a C13-spiked pooled serum sample was between 60 and 90% for all PCDD/F congeners and between 67 and 82% for the non-ortho PCBs. An adequate separation between both fractions was found. The CALUX/GC-HRMS ratio for a pooled serum sample was respectively 2.0 and 1.4 for the PCDD/Fs and the dl-PCBs, indicating the presence of additional AhR active compounds. As expected, a correlation was found between human serum samples analyzed with both the new H1L7.5c1 cell line and the more established H1L6.1c3 cell line. The geometric mean CALUX-BEQ values, reported for the adolescents of the second Flemish Environment and Health Study (FLEHS II) recruited in 2009-2010, were 108 (95% CI: 101-114) pg CALUX-BEQ/g fat for the PCDD/Fs and 32.1 (30.1-34.2) pg CALUX-BEQ/g fat for the dioxin-like PCBs.
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: E
authors.initials: E
authors.lastname: Den Hond
authors.forename: L
authors.initials: L
authors.lastname: Bruckers
authors.forename: A
authors.initials: A
authors.lastname: Colles
authors.forename: G
authors.initials: G
authors.lastname: Koppen
authors.forename: I
authors.initials: I
authors.lastname: Loots
authors.forename: V
authors.initials: V
authors.lastname: Nelen
authors.forename: G
authors.initials: G
authors.lastname: Schoeters
authors.forename: T
authors.initials: T
authors.lastname: Nawrot
authors.forename: N
authors.initials: N
authors.lastname: Van Larebeke
authors.forename: M S
authors.initials: MS
authors.lastname: Denison
authors.forename: T
authors.initials: T
authors.lastname: Vandermarken
authors.forename: M
authors.initials: M
authors.lastname: Elskens
authors.forename: W
authors.initials: W
authors.lastname: Baeyens
mesh_terms: D000293:Adolescent; D000818:Animals; D001530:Belgium; D001572:Benzofurans / Q000032:analysis* / Q000097:blood; D045744:Cell Line, Tumor; D000072338:Dibenzofurans, Polychlorinated; D004305:Dose-Response Relationship, Drug; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D057230:Limit of Detection; D008114:Liver Neoplasms, Experimental / Q000737:chemistry* / Q000473:pathology; D051379:Mice; D011078:Polychlorinated Biphenyls / Q000032:analysis* / Q000097:blood; D000072317:Polychlorinated Dibenzodioxins / Q000031:analogs & derivatives* / Q000032:analysis / Q000097:blood; D015203:Reproducibility of Results
chemical_list: D001572:Benzofurans; D000072338:Dibenzofurans, Polychlorinated; D000072317:Polychlorinated Dibenzodioxins; D011078:Polychlorinated Biphenyls