References of "Focant, Jean-François"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailPTV-LV-GC/MS/MS as screening and complementary method to HRMS for the monitoring of dioxin levels in food and feed
Eppe, Gauthier ULg; Focant, Jean-François ULg; Pirard, Catherine et al

in Talanta (2004), 63(5), 1135-1146

Recent developments in trapping efficiency inside ion trap mass spectrometer permitted to lower instrument detection limit (IDL). An IDL of 200 fg mul(-1) injected with a signal-to-noise ratio of 5:1 for ... [more ▼]

Recent developments in trapping efficiency inside ion trap mass spectrometer permitted to lower instrument detection limit (IDL). An IDL of 200 fg mul(-1) injected with a signal-to-noise ratio of 5:1 for tetrachlorodibenzo-p-dioxin (TCDD) was obtained by gas chromatography coupled to a quadrupole ion storage mass spectrometer in tandem mode (GC/MS/MS). Coupling large volume programmable temperature vaporizer (PTV-LV) injection to GC/MS/MS provides an alternative and complementary method to classical splitless-GC injection connected to high-resolution mass spectrometry (splitless-GC/HRMS) method for dioxin monitoring in food and feed. An injection volume of 10 mul was found to be the best compromise between the sensitivity requirements and the robustness required for a high throughput method. PTV-LV-GC/MS/MS and Splitless-GC/HRMS were compared by performing analysis on five different matrices such as beef fat, yolk eggs, milk powder, animal feed and serum samples covering a concentration range of two orders of magnitude (i.e. 0.2-25 ng WHO-TEQ kg(-1)). An analysis of variance (ANOVA) was carried out. Fisher tests pointed out that the method effect for all the 2,3,7,8 congeners was not significant, indicating that the null hypothesis (H-0: mu(1) = mu(2) = ... = mu(n)) was not rejected. Moreover, the interaction effects between methods and matrices were not significant for most of the 2,3,7,8 congeners. However, three congeners (2,3,7,8-TCDF; 1,2,3,4,7,8-HxCDD and I,2,3,4,6,7,8-HpCDD) were characterized by P-values lower than the significance level (alpha = 0.05). In toxic equivalence (TEQ), the study showed that no significant bias was observed between the two methods. Consequently, PTV-LV-GC/MS/MS is an attractive technique and can be used as a cost effective complementary method to HRMS for dioxin levels monitoring in food and feed. (C) 2004 Elsevier B.V. All rights reserved. [less ▲]

Detailed reference viewed: 104 (9 ULg)
Full Text
Peer Reviewed
See detailImproved separation of the 209 polychlorinated biphenyl congeners using comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry
Focant, Jean-François ULg; Sjödin, Andreas; Patterson, Donald G.

in Journal of Chromatography. A (2004), 1040(2), 227-238

The separation of the 209 polychlorinated biphenyl (PCB) congeners has been studied using comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC x GC-TOFMS). Four ... [more ▼]

The separation of the 209 polychlorinated biphenyl (PCB) congeners has been studied using comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC x GC-TOFMS). Four column combinations based on thermally stable phases, DB-1/HT-8, DB-XLB/HT-8, DB-XLB/BPX-50, and HT-8/BPX-50, have been investigated. The HT-8/BPX-50 set produced the best separation. The distribution of the 100 to 150 ms wide peaks was highly structured in the chromatographic space and based on the degree of ortho-substitution within each separated homologue series. A total of 192 congeners were resolved in 146 min (1.3 analyte per min) using this column set. Eight coelutions involved 17 congeners. Among them, seven congeners were present in Aroclors at levels >1.0 wt.% (CBs 33, 47, 48, 95, 97, 163, 187). Except for CBs 47 and 48, none of the major constituents of commercial mixtures were coeluting. CB 138 was well separated from CBs 163 and 164 in the second dimension. For all column sets, CBs 20, 33, and 109 always coeluted with other PCBs. The 12 toxic dioxin-like congeners (CBs 77, 81, 105, 114, 118, 123, 126, 156, 157, 167, 169, 189), and the seven European Union marker PCBs (CBs 28, 52, 101, 118, 138, 153, 180) were separated from any interfering congeners. This was not the case for the other investigated column sets. [less ▲]

Detailed reference viewed: 23 (4 ULg)
Peer Reviewed
See detailConcentration of Polybrominated Diphenyl Ethers (PBDEs) in House Hold Dust – Inhalation a Potential Route of Human Exposure.
sjodin; Papke; Mc Gahee et al

Poster (2004, June)

Detailed reference viewed: 2 (0 ULg)
See detailAutomated extraction and clean-up system for liquid materials
Focant, Jean-François ULg; De Pauw, Edwin ULg

Scientific conference (2004, April)

Detailed reference viewed: 1 (0 ULg)
See detailAutomated extraction and clean-up system for solid materials
Focant, Jean-François ULg; De Pauw, Edwin ULg

Scientific conference (2004, April)

Detailed reference viewed: 1 (0 ULg)
Full Text
Peer Reviewed
See detailLevels of PCDDs, PCDFs and PCBs in Belgian and international fast food samples
Focant, Jean-François ULg; Pirard, Catherine; De Pauw, Edwin ULg

in Chemosphere (2004), 54(1), 137-142

Congener-specific analyses of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and polychlorinated biphenyls (PCBs) were performed on twenty-eight non-pooled fast food ... [more ▼]

Congener-specific analyses of polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and polychlorinated biphenyls (PCBs) were performed on twenty-eight non-pooled fast food samples collected in Belgium, Switzerland, Czech Republic, United States of America and Australia. PCDD/F and PCB concentrations for the four investigated types of meals were very low. PCDD/F values ranged from non-detected to 1.40 pg WHO-TEQ/g fat and from 0.79 to 2.08 pg WHO-TEQ/g fat for lower and upper bound, respectively. Major contributors to the PCDD/F TEQ were 1,2,3,4,7,8-HxCDD, 1,2,3,6,7,8-HxCDD, 2,3,7,8-TCDF and 2,3,4,7,8-PeCDF. The relative contribution of PCBs to the total TEQ was 68%. For adults, an average estimated intake was 6.7 pg WHO-TEQ/kg bw/month, including consumption of all types of analyzed meals, representing 9.5% of the PTMI. For child, a value of 14.5 pg WHO-TEQ/kg bw/month was obtained, representing 20.6% of the PTMI. (C) 2003 Elsevier Ltd. All rights reserved. [less ▲]

Detailed reference viewed: 26 (2 ULg)
Full Text
Peer Reviewed
See detailHigh-throughput analysis of human serum for selected polychlorinated biphenyls (PCBs) by gas chromatography-isotope dilution time-of-flight mass spectrometry (GC-IDTOFMS)
Focant, Jean-François ULg; Cochran, Jack W.; Dimandja, Jean-Marie D. et al

in Analyst (2004), 129(4), 331-336

A method for the high-throughput analysis of human serum for the 38 most prevalent polychlorinated biphenyls (PCBs) based on the use of fast gas chromatography-isotopic dilution time-of-flight mass ... [more ▼]

A method for the high-throughput analysis of human serum for the 38 most prevalent polychlorinated biphenyls (PCBs) based on the use of fast gas chromatography-isotopic dilution time-of-flight mass spectrometry (GC-IDTOFMS) is presented. The chromatographic separation time was 8 min. The separation of the congeners was carried out either chromatographically or analytically using the mass spectral deconvolution capability of the TOFMS. The instrument and the method limits of detection (LODs) were 0.5 pg muL(-1) and 20 pg muL(-1), respectively, which is not as good as the one achieved using high resolution mass spectrometry (HRMS) but allows the detection and quantification of the prevalent PCBs present in real human serum samples. The dynamic range covered 3 orders of magnitude. The comparison with the high resolution mass spectrometry (HRMS) reference method (28 min) was good and some separation improvements have been observed. This method allows the analysis of 100 samples per day per instrument. [less ▲]

Detailed reference viewed: 22 (3 ULg)
Full Text
Peer Reviewed
See detailConcentration of Polybrominated Diphenyl Ethers (PBDEs) in house hold dust from various countries - inhalation a potential route of human exposure
Sjödin; Päpke, Olaf; McGaheeIII, Ernest et al

in Organohalogen Compounds (2004), 66

Detailed reference viewed: 33 (1 ULg)
Full Text
Peer Reviewed
See detailGCxGC-TOFMS of chlorinated dioxins and furans in environmental samples
Cochran, Jack; Focant, Jean-François ULg; Sjödin, Andreas et al

in Organohalogen Compounds (2004), 66

Detailed reference viewed: 31 (0 ULg)
Full Text
Peer Reviewed
See detailMeasurement of selected halogenated contaminants in human serum and milk using GCxGC-IDTOFMS
Focant, Jean-François ULg; sjodin, Andreas; Turner, Wayman et al

in Organohalogen Compounds (2004)

Detailed reference viewed: 5 (0 ULg)
Full Text
Peer Reviewed
See detailImproved separation of the 209 PCBs using GCxGC-TOFMS
Focant, Jean-François ULg; Sjödin, Andreas; Patterson, Donald G.

in Organohalogen Compounds (2004), 66

Detailed reference viewed: 24 (1 ULg)
Full Text
Peer Reviewed
See detailContribution of tobacco smoking to dioxin accumulation: opposite effects according to gender
Fierens, Sébastian; Eppe, Gauthier ULg; Focant, Jean-François ULg et al

in Organohalogen Compounds (2004), 66

Detailed reference viewed: 17 (1 ULg)
Full Text
Peer Reviewed
See detailImproved separation and quantification of dioxin and furan congeners using Novel low-bleed capillary gas chromatography columns and mass spectrometry
Dorman, Frank; Reese, Shawn; Reiner, Eric et al

in Organohalogen Compounds (2004), 66

Detailed reference viewed: 7 (0 ULg)