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Waterlot C.,Laboratoire Genie Civil et geo Environnement LGCgE | Goulas A.,Laboratoire Genie Civil et geo Environnement LGCgE | Goulas A.,Lille 2 University of Health and Law
Journal of Chemistry

Effects of temperature on the reversed-phase chromatographic behavior of PAHs were investigated on three columns. The first was the recent C18 column (250 mm × 4.6 mm) packed with 5 μm core-shell particles while the others were more conventional C18 columns (250 mm × 4.6 mm) packed with fully porous particles. Among the 16 PAHs studied, special attention has been paid to two pairs of PAHs, fluorene/acenaphthene and chrysene/benzo[a]anthracene, which often present coeluting problems. Due to the low surface area of the core-shell particles, lowest retention time of each PAH was highlighted and effects of the temperature on the separation of PAHs were negligible in regard to those using columns packed with fully porous particles. For each PAH studied, it was demonstrated that peaks were symmetrical and may be considered as Gaussian peaks when the column packed with core-shell particle was employed. In the best condition, the separation of PAHs was conducted at 16°C under very low pressure values (670-950 psi = 46-65 bars). Depending on PAHs, the limit of detection ranged from 0.88 to 9.16 μg L-1. Analysis of spiked acetonitrile samples with PAHs at 10 and 50 μg L-1 and tap water at 10 μg L-1 gave very good recoveries (94%-109.3%) and high precision (1.1%-3.5%). © 2016 Christophe Waterlot and Anaïs Goulas. Source

Waterlot C.,Laboratoire Genie Civil et geo Environnement LGCgE | Douay F.,Laboratoire Genie Civil et geo Environnement LGCgE
Environmental Science and Pollution Research

Emissions from primary lead smelters have been recognized as one of the mainly factor which has contributed to the contamination of soils by metals. Less attention has been paid to volatile metalloids such as arsenic (As) which accompanies lead (Pb) smelting activities. One of the objectives of this study was to determine the As concentrations in various extracting solutions using a collection of urban soils located no far away from two former Pb and zinc plants in the North of France. The procedure for the determination of As, AsIII, and AsV with hydride vapor generator atomic absorption spectrometry was described in details. Pseudo-total concentrations of As in the studied soils ranged from 5.3 to 65.9 mg kg−1. Good correlations were found between As and lead, zinc, and cadmium concentrations in soils. These depended on the soil uses and the soil distance from the source of contamination. Because the form of As may pose a health risk to human population, its speciation was determined in each urban top soils. Very good correlations were found between AsIII and AsV versus As concentrations in soils studied, but the results did no permit to establish a relation between the location of soils and their uses. In contrast, it was shown that the highest mobility factor and lowest partitioning index values were related to the location. The mobilty of As depended on the assimilated phosphorus (P), carbonate contents, and pH. The percentages of the water-extractable As concentrations ranged from 0.3 to 3.0 % of the As concentrations in soils. Very good positive correlations between water-extractable AsIII and AsV versus water-extractable As concentrations were obtained. It was shown that the water-extractable AsIII concentrations depended on the soil uses. The results revealed that soils for which the As was the most mobile presented the highest water-extractable As concentrations. Principal component analysis indicated that mechanisms related to the release of As depended on the physico-chemical parameters of the soils, particularly on the assimilated P, organic matter, and/or iron oxides/hydroxides contents. Finally, the glasshouse experiments using ryegrass as plant model and three soils with similar physico-chemical parameters with regard to the PCA analysis showed that the water extracting solution could be a good indicator to evaluate the As phytoavailability. © 2014, Springer-Verlag Berlin Heidelberg. Source

Pelfrene A.,Laboratoire Genie Civil et geo Environnement LGCgE | Waterlot C.,Laboratoire Genie Civil et geo Environnement LGCgE | Guerin A.,French National Institute for Agricultural Research | Proix N.,French National Institute for Agricultural Research | And 2 more authors.
Environmental Geochemistry and Health

Metal contamination of urban soils and homegrown vegetables has caused major concern. Some studies showed that cadmium (Cd) was among the most significant hazards in kitchen garden soils and prolonged exposure to this metal could cause deleterious health effects in humans. In general, most risk assessment procedures are based on total concentrations of metals in vegetables. The present study assesses human bioaccessibility of Cd in vegetables cultivated in smelter-impacted kitchen garden soils. Seven vegetables (radish, lettuce, French bean, carrot, leek, tomato, and potato) were considered. Using the UBM protocol (unified BARGE bioaccessibility method), the bioaccessibility of Cd was measured in raw/cooked vegetables. A considerable amount of Cd was mobilized from raw vegetables during the digestion process (on average 85 % in the gastric phase and 69 % in the gastrointestinal phase), which could be attributed to a high uptake of Cd during the growth of the vegetables. Most Cd is accumulated in the vacuoles of plant cells, except what is absorbed by the cell wall, allowing Cd to be released from plant tissues under moderate conditions. Cooking by the steaming process generally increased the bioaccessibility of Cd in French bean, carrot, and leek. For potato, few or no significant differences of Cd bioaccessibility were observed after the steaming process, while the frying process strongly decreased bioaccessibility in both phases. The estimation of metal bioaccessibility in vegetables is helpful for human health risk assessment. © 2015, Springer Science+Business Media Dordrecht. Source

Goulas A.,Laboratoire Genie Civil et geo Environnement LGCgE | Louvel B.,Laboratoire Genie Civil et geo Environnement LGCgE | Waterlot C.,Laboratoire Genie Civil et geo Environnement LGCgE
Canadian Journal of Chemistry

An ultrafast liquid chromatography method with fluorescence detection has been optimized for the determination of 15 polycyclic aromatic hydrocarbons (PAHs) using a recent Kinetex-C18 column (250 mm × 4.6 mm). This column has been recently packed with a new brand of porous shell particles with an average particle size of 5 μm to separate various compounds by liquid chromatography, operating at very low pressure. After optimization of the analytical procedure, the separation of the 15 PAHs in spiked tap water samples was achieved without coeluted products in 21.5 min at 16 °C using an aqueous/acetonitrile mobile phase under gradient concentrations with a very low flow rate (0.7-1.0 mL min-1) and low pressure values (870-1590 psi = 60-110 bar), all of these conditions being interesting from an economic point of view. The synchronization of wavelength time changing and the elution time of each compound was performed to avoid baseline deviation. The validation of the whole of the experimental procedure was conducted taking into consideration the following parameters: calibration curve, linearity, limits of detection and quantification, accuracy, sensitivity, precision, and repeatability of the retention time for each PAH. The proposed analytical procedure presented adequate linearity over a concentration range from 0.025 to 10 μg L-1 with a correlation coefficient better than 0.9980. The repeatability (relative standard deviation in percentage, n = 5) of the retention time for the different PAHs investigated ranged from 0.03% to 0.34% and the limit of detection was under 0.6 μg L-1 for most PAHs (excepted for indeno[1,2,3-c,d]pyrene, limit of detection = 1.71 μg L-1). The intraday and interday precisions were below 4%. The recovery of PAH in spiked tap water samples was variable, ranging from 96% to 109%, with relative standard deviation between 0.2% and 4.8%, depending on PAHs and their concentration levels. © 2015 Published by NRC Research Press. Source

Alhaj Hasan O.,Laboratoire Genie Civil et geo Environnement LGCgE | Defer D.,University of Artois | Shahrour I.,Laboratoire Genie Civil et geo Environnement LGCgE
Energy and Buildings

This paper proposes a new method for an optimal control of the heating system at the building scale. This control is a new approach of energy planning that aims to decrease the heating consumption/expenses over a defined prediction horizon while respecting the occupants' thermal comfort. It employs a simplified building thermal model to simulate the building thermal behavior taking into consideration the weather predictions. This approach is based on the application of Monte Carlo method, i.e., a random generator for the heating system scenarios. The aim is to determine the optimal heating plan for the prediction horizon that fulfills the constraints regarding the thermal comfort of occupants and the minimization of the energy consumption/expenses together with achieving a load shedding. © 2014 Elsevier B.V. Source

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