References of "Focant, Jean-François"
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See detailRecent advances in mass spectrometric measurement of dioxins
Focant, Jean-François ULg; Pirard, Catherine ULg; Eppe, Gauthier ULg et al

in Journal of Chromatography. A (2005), 1067(1-2), 265-275

Past years, many efforts have been dedicated to the development of alternative analytical methods for the measurement of dioxins in various types of matrices. Polychlorinated dibenzo-p-dioxins (PCDDs ... [more ▼]

Past years, many efforts have been dedicated to the development of alternative analytical methods for the measurement of dioxins in various types of matrices. Polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs), and polychlorinated biphenyls (PCBs) are compounds that are present in samples at part-per-billion (ppb) or part-per-trillion (ppt) level. Their measurement requires the use of very sensitive analytical methods. Gas chromatography (GC) coupled to quadrupole ion storage mass spectrometry (QISTMS), fast GC (FGC) coupled to time-of-flight mass spectrometry (TOFMS) and comprehensive two-dimensional gas chromatography (GC x GC) coupled to TOFMS are the more promising tools challenging the reference GC high resolution mass spectrometry (HRMS) based on sector instruments. We report herein some of the advances we achieved in the past years in our laboratory on the development of alternative measurement methods for those compounds. (c) 2004 Elsevier B.V. All rights reserved. [less ▲]

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See detailComprehensive two-dimensional gas chromatography with isotope dilution time-of-flight mass spectrometry for the measurement of dioxins and polychlorinated biphenyls in foodstuffs - Comparison with other methods
Focant, Jean-François ULg; Eppe, Gauthier ULg; Scippo, Marie-Louise ULg et al

in Journal of Chromatography. A (2005), 1086(1-2), 45-60

A comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry (GC x GC-TOF-MS) experimental setup was tested for the measurement of seven 2,3,7,8-substituted polychlorinated dibenzo ... [more ▼]

A comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry (GC x GC-TOF-MS) experimental setup was tested for the measurement of seven 2,3,7,8-substituted polychlorinated dibenzo-p-dioxins (PCDDs), ten 2,3,7,8-substituted polychlorinated dibenzofurans (PCDFs), four non-ortho-polychlorinated biphenyls (PCBs), eight mono-ortho-PCBs, and six indicator PCBs (Aroclor 1260) in foodstuff samples. A 40 m RTX-500 (0.18 mm I.D., 0.10 mu m df) was used as the first dimension (D-1) and a 1.5 nn BPX-50 (0.10 mm I.D., 0.10 mu m df) as the second dimension (2 D). The GC x GC chromatographic separation was completed in 45 min. Quantification was performed using C-13-label isotope dilution (11)). Isotope ratios of the selected quantification ions were checked against theoretical values prior to peak assignment and quantification. The dynamic working range spanned three orders of magnitude. The lowest detectable amount of 2,3,7,8-TCDD was 0.2 pg. Fish, pork, and milk samples were considered. On a congener basis, the GC x GC-ID-TOF-MS method was compared to the reference GC-ID high resolution mass spectrometry (HRMS) method and to the alternative GC-ID tandem-in-time quadrupole ion storage mass spectrometry (QIST-MS/MS). PCB levels ranged from low picogram (pg) to low nanogram (ng) per gram of sample and data compared very well between the different methods. For all matrices, PCDD/Fs were at a low pg level (0.05-3 pg) on a fresh weight basis. Although congener profiles were accurately described, RSDs of GC x GC-ID-TOF-MS and GC-QIST-MS/MS were much higher than for GC-ID-HRMS, especially for low level pork and milk. On a toxic equivalent (TEQ) basis, all methods, including the dioxin-responsive chemically activated luciferase gene expression (DR-CALUX) assay, produced similar responses. A cost comparison is also presented. (c) 2005 Elsevier B.V. All rights reserved. [less ▲]

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See detailEvaluation of the DR-CALUX screening of food and feed, according to regulation levels including DL-PCB
Scippo, Marie-Louise ULg; Rybertt, Soledad; Focant, Jean-François ULg et al

in Organohalogen Compounds (2005), 67

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See detailThe Use of Cryogenic Zone Compression for the Measurement of POPs in Human Serum at Attogram Levels by GCxGC/ID-HRMS
Patterson, Donald G.; Welch, Susan; Turner, Wayman et al

in Organohalogen Compounds (2005), 67

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See detailPerformance of GC-LRMS/MS and GCxGC methods for compliance monitoring of the PCDD/F-TEQ and the total TEQ in food and feed
Van Cleuvenbergen, Rudy; Santos, Javier; Eppe, Gauthier ULg et al

in Organohalogen Compounds (2005), 67

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See detailIdentification of Potential Biomarkers of Human Peripheral Blood Mononuclear Cell intoxication by dioxins
Brenez, Cécile; Cellier, Nicolas; Gerkens, Pascal et al

in Organohalogen Compounds (2005), 67

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See detailRemoval of PCDD/Fs and DL-PCBs from fish oil by activated carbon: Compliance with European Legislation
Eppe, Gauthier ULg; Carbonnelle, Sophie; Hellebosch, Laeticia et al

in Organohalogen Compounds (2005), 67

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See detailDecrease of serum concentrations of dioxins and PCBs in Belgium between 2000 and 2003
Fierens, Sébastien; Heilier, Jean-François; Eppe, Gauthier ULg et al

in Organohalogen Compounds (2005), 67

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See detailMeasurement of Dioxins and WHO-PCBs in Foodstuffs using GCxGC-IDTOFMS
Focant, Jean-François ULg; De Pauw, Edwin ULg

Scientific conference (2004, December)

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See detailMeasurement of selected polybrominated diphenyl ethers, polybrominated and polychlorinated biphenyls, and organochlorine pesticides in human serum and milk using comprehensive two-dimensional gas chromatography isotope dilution time-of-flight mass spectrometry
Focant, Jean-François ULg; Sjodin, Andreas; Turner, Wayman E. et al

in Analytical Chemistry (2004), 76(21), 6313-6320

A new method using comprehensive two-dimensional gas chromatography and isotope dilution time-of-flight mass spectrometry (GC x GC-IDTOFMS) for the simultaneous measurement of selected polychlorinated ... [more ▼]

A new method using comprehensive two-dimensional gas chromatography and isotope dilution time-of-flight mass spectrometry (GC x GC-IDTOFMS) for the simultaneous measurement of selected polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), and brominated flame retardants is presented. In contrast to the reference methods based on classical GC/MS, a single injection of the extract containing all compounds of interest results in accurate identification and quantification. Using GC x GC ensures the chromatographic separation of most compounds, and TOFMS allows mass spectral deconvolution of coeluting compounds as well as the use of C-13-labeled internal standards for quantification. Isotope ratio measurements of the most intense ions for both native and labels ensure the required specificity. The use of this new method with an automated sample preparation procedure developed at the Centers for Disease Control and Prevention (CDC) for the analysis of human serum and milk compared favorably to conventional isotope-dilution one-dimensional gas chromatography-high-resolution mass spectrometty (GC-IDHRMS) for the different human serum and milk pools tested. The instrumental detection limits ranged between 0.5 pg/muL and 10 pg/muL and the method detection limits ranged between I and 15 pg/muL (N = 59 analytes). The reproducibility of the method was almost as good as with GC-IDHRMS, the relative standard deviations ranging between 1 and 11% for OCPs measured in human serum. OCP, PBDE, and PCB levels measured using the two methods were highly correlated, and the deviations between the two methods were below 20% for most analytes with concentrations above 1 ng/g milk lipids. [less ▲]

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