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Incorporation of powdered iron into the root bed of experimental constructed wetlands removes phosphorus from treated sewage to levels that easily meet government guidelines for discharge into natural water bodies. Various combinations of... more
Incorporation of powdered iron into the root bed of experimental constructed wetlands removes phosphorus from treated sewage to levels that easily meet government guidelines for discharge into natural water bodies. Various combinations of powdered iron and sand were used to determine the best arrangement that removes the largest amount of phosphorus. Macrophytes fulfill a beneficial function by delivering oxygen to the root zone and by improving drainage in the wetland. In these wetlands, cattails (Typha latifolia L.) also take up phosphorus during growth and store significant quantities of it in their leaves.
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Research Interests: Environmental Engineering, Environmental Science, Arsenic, Great Lakes, Environmental Chemistry, and 15 moreAtmospheric deposition, Copper, Heavy Metal, Polycyclic Aromatic Hydrocarbon, Sediment, Nickel, Contamination, Lake Erie, Polychlorinated Biphenyl, Lake superior, Great Salt Lake, Bay, Bedrock, ENVIRONMENTAL SCIENCE AND MANAGEMENT, and Organochlorine pesticide
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Research Interests: Engineering, Chemistry, Chromatography, Industrial Biotechnology, Magnetic Resonance Spectroscopy, and 15 moreMedicine, Quantitative analysis, Isotopes, Calibration, Red Wine, CHEMICAL SCIENCES, Beverages, Harmonia axyridis, Polydimethylsiloxane, Food Sciences, Quantitative Analysis, Elsevier, Reference standards, Relative Standard Deviation, and limit of detection
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Temporal trends and seasonal variation of Dechloranes (Dec) 602, 603, 604, and Chlordene Plus (CP) in Niagara River suspended sediment, a Lake Ontario sediment core, and Lake Ontario lake trout were investigated, with Mirex and Dechlorane... more
Temporal trends and seasonal variation of Dechloranes (Dec) 602, 603, 604, and Chlordene Plus (CP) in Niagara River suspended sediment, a Lake Ontario sediment core, and Lake Ontario lake trout were investigated, with Mirex and Dechlorane Plus (DP) included for comparison. Temporal concentration trends were generally consistent in each of the media for all compounds with the lowest concentrations observed in or after the late 1990s. In Niagara River suspended sediments, all compounds showed seasonal variation over a year with distinct profiles observed. The relative concentration patterns observed were total DP > Mirex > Dec 602 and Dec 604 > Dec 603 > CP in suspended sediments and sediment cores, whereas Mirex was highest in lake trout, followed by Dec 602 and DP. Dec 602 concentrations were 50 to 380 times greater than those of DP in lake trout, indicating Dec 602 has a greater bioaccumulation potential. The estimated biota-sediment accumulation factor (BSAF) for Dec 602 was much greater than for DP in Lake Ontario, and was greater than those calculated for PBDEs, indicating that assessment of some dechlorane compounds is merited if use is ongoing or planned.
Research Interests: Environmental Science, Bioaccumulation, Environmental Monitoring, Environmental Chemistry, Medicine, and 13 moreMultidisciplinary, Environmental science and technology, Great Lakes Region, Concentration, Animals, Sediments, Sediment, Fresh water, Trout, Biota, Environmental, Geologic Sediments, and Flame Retardants
A chlorinated compound (Chlordene Plus, CP), structurally related to Dechloranes (Dec) 602, 603, 604, and Dechlorane Plus (DP), was identified, and concentrations and spatial trends of Dec 602, 603, 604, CP, and DP in tributary sediments... more
A chlorinated compound (Chlordene Plus, CP), structurally related to Dechloranes (Dec) 602, 603, 604, and Dechlorane Plus (DP), was identified, and concentrations and spatial trends of Dec 602, 603, 604, CP, and DP in tributary sediments of the Laurentian Great Lakes are reported. The dechloranes were widely detected with their concentrations varying considerably across the Great Lakes basin. Spatial trends of Dec 602, 604, and DP in Canadian tributary sediments were similar to that of BDE 209, which suggested these flame retardant chemicals in tributaries were associated with industrial and urban areas. The highest concentrations of Dec 602, 604, and DP observed in tributaries of the Niagara River confirmed that past or ongoing manufacturing of these compounds at plants along the river were important sources to Lake Ontario. Dec 603 was detected in technical products of aldrin and dieldrin, and its spatial trend was consistent with historic pesticide usage. Similarly, CP was detected in technical products of chlordene and chlordane, and it was found in higher concentrations in sediments near urban areas, possibly related to past chlordane use in home termite control.
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Research Interests: Environmental Science, Statistical Analysis, Environmental Monitoring, Environmental Pollution, Medicine, and 15 moreMultidisciplinary, Pulp and Paper, Canada, Atmospheric deposition, Pesticides, Land Use, Polychlorinated Biphenyls, Polychlorinated Biphenyl, Lake superior, Fresh water, Environmental, Geologic Sediments, Tributary, Air Pollutants, and Submarine Pipeline
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The crystal structure of (E)-6-(bromomethylene)-5,6-dihydro-4,4-dimethyl-2-phenyl-4H-1,3,4-oxadiazinium bromide has been determined by single crystal X-ray diffraction methods. The crystals are monoclinic, space group P21/c, with... more
The crystal structure of (E)-6-(bromomethylene)-5,6-dihydro-4,4-dimethyl-2-phenyl-4H-1,3,4-oxadiazinium bromide has been determined by single crystal X-ray diffraction methods. The crystals are monoclinic, space group P21/c, with a = 12.002(5), b = 6.414(4), c = 17.881(7) Å, β = 101.42(7)°, and Z = 4 formula units of C12H14N2OBr2. The structure was refined by full-matrix least-squares analysis to a conventional R-factor of 0.0491 for 1019 observed reflections. The oxadiazinium ring is in the half-chair form, with the methylene group out of the plane defined by the other five atoms. The C—O bond distances in the ring are somewhat shorter than the distance observed for a carbon–oxygen single bond, suggesting that some delocalization of electron density occurs over part of the ring.
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Halonitromethanes (HNMs) are one of the most cytotoxic and genotoxic classes found among the unregulated disinfection by-products formed by the reaction of chemical disinfectants with natural organic matter in water. Typical methods used... more
Halonitromethanes (HNMs) are one of the most cytotoxic and genotoxic classes found among the unregulated disinfection by-products formed by the reaction of chemical disinfectants with natural organic matter in water. Typical methods used to determine these compounds in water (mainly trichloronitromethane) are based on the Environmental Protection Agency (EPA) method 551.1 using liquid-liquid extraction. A fast and straightforward method for the determination of the nine HNMs in water has been developed using a static headspace (HS) coupled with gas chromatography-mass spectrometry (GC-MS). Important parameters controlling headspace extraction were optimised to obtain the highest sensitivity: 250 μL of methyl tert-butyl ether (as a chemical modifier) and 6 g of anhydrous sodium sulphate were added to the water sample; an oven temperature of 80 °C and an equilibration time of 20 min were also selected. The addition of a chemical modifier favoured the volatilisation of all HNMs, increasing their signals up to approximately four times. Under optimum conditions, the method developed provides limits of detection between 0.03 and 0.60 μg/L and a relative standard deviation of ~6.0%. The developed method was validated and then compared with the reference method EPA 551.1 for the analysis of tap and swimming pool water. A good agreement in the results was observed, which corroborated the good performance of the proposed HS-GC-MS method.
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The development, optimization and validation of a liquid chromatography-atmospheric pressure photoionization tandem mass spectrometric (LC-APPI/MS/MS) method for the determination of 15 azaarenes (4-azafluorene, benzo[h] and... more
The development, optimization and validation of a liquid chromatography-atmospheric pressure photoionization tandem mass spectrometric (LC-APPI/MS/MS) method for the determination of 15 azaarenes (4-azafluorene, benzo[h] and -[f]quinoline, phenanthridine, acridine, 1-azafluoranthene, 4-azapyrene, benz[a]- and -[c]acridine, -10-azabenzo[a]pyrene, 7,9- and 7,10-dimethylbenz[c]acridine, dibenz[a,j]-, -[c,h] and [a,i]acridine) in airborne particulate matter is described. Each compound was detected and quantified operating in multiple reaction monitoring mode. Extraction of azaarenes was achieved using accelerated solvent extraction (ASE) with dichlormethane/methanol (50/50, v/v). After extraction, no additional clean-up procedure like solid phase or liquid/liquid extraction was necessary. Limits of quantification (S/Nx10) ranged from 0.2 pg/microl to 1.4 pg/microl, matrix dependent recoveries were between 57% and 94%, with relative standard deviations from 8% to 17%. Applicability of the method was demonstrated analyzing 10 samples of particulate matter (PM(2.5)) collected in winter 2008. In all samples dimethylbenz[c]acridines as well as dibenzacridines were below the limit of quantification, concentration of the remaining analytes were in the range from 0.002 ng/m(3) to 0.356 ng/m(3).
Research Interests: Engineering, Chemistry, Technology, Chromatography, Mass Spectrometry, and 13 moreLiquid Liquid Extraction, Atmospheric Pressure, Tandem Mass Spectrometry, High Pressure Liquid Chromatography, CHEMICAL SCIENCES, Liquid Chromatography / Electrospray Ionization Mass Spectrometry, Liquid Chromatography, Particulate Matter, Air Pollutants, Acridine, Accelerated Solvent Extraction, airborne particulate matter, and Relative Standard Deviation
Investigations into the use of experimental membranes (Empore), containing iminodiacetate residues, as well as Millipore SEP PAK cartridges, containing either acid or basic alumina, have been carried out at the Ontario Ministry of... more
Investigations into the use of experimental membranes (Empore), containing iminodiacetate residues, as well as Millipore SEP PAK cartridges, containing either acid or basic alumina, have been carried out at the Ontario Ministry of Environmental and Energy laboratories in Rexdale, Ontario. In this paper, we report the results of our investigations by ICP mass spectrometry of recoveries of metal ions from drinking and surface waters.
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Nickel, chromium, zinc and lead were 60 to 500 times more concentrated in the sediments downstream of the Atlas Specialty Steels Co. than they were in the sediments of the upper Welland River or in the nearby Lyon’s Creek. These metals... more
Nickel, chromium, zinc and lead were 60 to 500 times more concentrated in the sediments downstream of the Atlas Specialty Steels Co. than they were in the sediments of the upper Welland River or in the nearby Lyon’s Creek. These metals reached concentrations of 4,900 mg kg−1 dry weight (ppm) of nickel versus 10 ppm upstream, 890 versus 5 ppm lead, 1,050 versus 30 ppm zinc and 5,120 verses 10 ppm chromium. Changes in higher aquatic plant species composition and relative abundance downstream of the Atlas Specialty Steels Co. were plotted as a function of the downstream distance (800 m) from the point source discharge of the company. Four zones in the distribution patterns of aquatic plants were recognized. In the first zone (0–10 m from the point source) benthic invertebrates and aquatic plants were absent. In zone 2 (10–15 m from the point source) pollution tolerant benthic invertebrates such as sludge worms and blood worms as well as pollution tolerant long stemmed emergent macrophy...
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Salicylic acid (SA) is an essential hormone in plant immunity, but its receptor has remained elusive for decades. The transcriptional coregulator NPR1 is central to the activation of SA-dependent defense genes, and we previously found... more
Salicylic acid (SA) is an essential hormone in plant immunity, but its receptor has remained elusive for decades. The transcriptional coregulator NPR1 is central to the activation of SA-dependent defense genes, and we previously found that Cys(521) and Cys(529) of Arabidopsis NPR1's transactivation domain are critical for coactivator function. Here, we demonstrate that NPR1 directly binds SA, but not inactive structural analogs, with an affinity similar to that of other hormone-receptor interactions and consistent with in vivo Arabidopsis SA concentrations. Binding of SA occurs through Cys(521/529) via the transition metal copper. Mechanistically, our results suggest that binding of SA causes a conformational change in NPR1 that is accompanied by the release of the C-terminal transactivation domain from the N-terminal autoinhibitory BTB/POZ domain. While NPR1 is already known as a link between the SA signaling molecule and defense-gene activation, we now show that NPR1 is the re...
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The products of the reactions of FeII, NiII and CoII with sodium tetrahydroborate(III), which interfere with the determination of selenium by hydride generation, were precipitated by different methods and investigated by potentiometric... more
The products of the reactions of FeII, NiII and CoII with sodium tetrahydroborate(III), which interfere with the determination of selenium by hydride generation, were precipitated by different methods and investigated by potentiometric titration accompanied by monitoring of hydrogen evolution, direct current plasma atomic emission spectrometry and positive ion FAB mass spectrometry. Boron was found in the precipitates of NiII and CoII but not FeII obtained from the acid solutions under the conditions of hydride generation. Several sections on the potentiometric titration curves were found, which indicated the formation of several boride-like compounds with different compositions depending on the sequence of mixing reagents, pH, reactant concentrations and ratios, speed of mixing and the presence of oxygen. A hypothesis was formulated about the reduction of boronIII from sodium tetrahydroborate(III) to lower oxidation states of boron in boride-like species which is used to explain the properties of the potentiometric titration curves and the suppression of the selenium hydride signal in hydride generation.
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A reversed-phase high-performance liquid chromatographic (HPLC) method has been developed for the determination of trace concentrations of benomyl, carbendazim, aldicarb, aldicarb sulphoxide and aldicarb sulphone in drinking water. A... more
A reversed-phase high-performance liquid chromatographic (HPLC) method has been developed for the determination of trace concentrations of benomyl, carbendazim, aldicarb, aldicarb sulphoxide and aldicarb sulphone in drinking water. A 10-ml sample of water is passed through a 3-cm precolumn, packed with 5-microns C8 sorbent, at a flow-rate of 5 ml/min. The HPLC system is then switched to an acetonitrile-water gradient elution program. The preconcentrated analytes are eluted from, and separated by, the 3-cm C8 precolumn and determined by UV absorption. The total analytical time is 25 min. The lowest detectable concentrations are in the range of 2.5 x 10(-9)-11.0 x 10(-9) g/ml for the five analytes investigated with 10 ml of sample.
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... DOI: 10.1039/a908658g J. Anal. At. Spectrom., 2000, 15, 409±413 409 This journal is © The Royal Society of Chemistry 2000 Downloaded on 15 January 2011 Published on http://pubs.rsc.org | doi:10.1039/a908658g View Online Page 2. ...
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Page 1. Determination of arsenic, antimony, bismuth, germanium, tin, selenium and tellurium in 30% zinc sulfate solution by hydride generation inductively coupled plasma atomic emission spectrometry Christine Rigby and Ian D. Brindle* ...
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J. Anal. At. Spectrom., 2001, 16, 289-292 DOI:10.1039/B007377F (Technical Note). Determination of hydride-forming elements in high purity coppers by inductively coupled plasma atomic emission spectrometry. Sarah D. Overduin ...
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Page 1. 1758 J. Agric. Food Chem. 1990, 38, 1758-1762 Kinetic Study of the Decomposition of Methyl [ 1 -( Butylcarbamoyl)-1H-benzimidazol-2-yl]carbamate (Benomyl) to Methyl 1H-Benzimidazol-2-ylcarbamate (MBC) Raj P. Singhz and Ian D.... more
Page 1. 1758 J. Agric. Food Chem. 1990, 38, 1758-1762 Kinetic Study of the Decomposition of Methyl [ 1 -( Butylcarbamoyl)-1H-benzimidazol-2-yl]carbamate (Benomyl) to Methyl 1H-Benzimidazol-2-ylcarbamate (MBC) Raj P. Singhz and Ian D. Brindle ...
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ABSTRACT 3-Alkyl-2-methoxypyrazines (MPs) are grape- and insect-derived odour-active compounds responsible for green and vegetative perceptions in wine, and at elevated concentrations are detrimental to wine quality. We examined the... more
ABSTRACT 3-Alkyl-2-methoxypyrazines (MPs) are grape- and insect-derived odour-active compounds responsible for green and vegetative perceptions in wine, and at elevated concentrations are detrimental to wine quality. We examined the influence of light and temperature during cellaring on MPs and other impact odourants. Riesling and Cabernet Franc wines were supplemented with 30ng/L of each of 3-isopropyl-2-methoxypyrazine (IPMP), 3-s-butyl-2-methoxypyrazine (SBMP) and 3-isobutyl-2-methoxypyrazine (IBMP), and stored under one of the following conditions: (i) at ambient temperature (22°C) under fluorescent lighting, (ii) in the dark at ambient temperature, or (iii) in the dark at cellar temperature (12°C). Additionally, for the light condition, wine was stored in clear, green or amber bottles.MPs did not vary consistently over time under any of these light or temperature conditions. IBMP decreased over 12month by approx. 30% under all conditions in both Riesling and Cabernet Franc. Acetate esters also decreased with time, regardless of light or temperature conditions, while phenethyl acetate and isoamyl acetate decreased at a greater rate at 22°C compared with 12°C. Free and bound SO2 retention was higher in light-excluded conditions and influenced by bottle hue. Measures of browning and phenolic content were also affected to varying degrees by bottle hue and storage temperature. These results should assist winemakers in selecting bottle hues, and assist in selection of optimum storage conditions for preserving wine quality in both retail and cellar environments.
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Allylic and propargylic amineimides react with bromine to form 4H-1,3,4-oxadiazinium salts in accord with recent studies of electrophilic brominations. A novel synthesis of 5,6-... more
Allylic and propargylic amineimides react with bromine to form 4H-1,3,4-oxadiazinium salts in accord with recent studies of electrophilic brominations. A novel synthesis of 5,6- dihydro-4,4-dimethyl-6-hydroxymethyl-2-phenyl-4H-1,3,4-oxadiazinium bromide by the reaction of N′N′-dimethylbenzohydrazide and epibromohydrin is reported.
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Page 1. Methyl substituted thioxanthones and thioxanthone-10,lO-dioxides IAN D. BRINDLE' AND PAUL P. DOYL~ Del~crrt~rleirr of' Chei~ii.cti~. Brock Ur1ri~o..tit\.. St. Cat/~oi.i~~ct , O i ~ t . , Coilcrclo... more
Page 1. Methyl substituted thioxanthones and thioxanthone-10,lO-dioxides IAN D. BRINDLE' AND PAUL P. DOYL~ Del~crrt~rleirr of' Chei~ii.cti~. Brock Ur1ri~o..tit\.. St. Cat/~oi.i~~ct , O i ~ t . , Coilcrclo L2S .?A / Rcccivcd Dcccmbcr 10. 1982 IAN D. BRINDLE and PAUL P. DOYLE. ...
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Page 1. Bull. Chem. Soc. Jpn., 68, 341349(1995) 341 Thermal Rearrangement of iV-Alkyl-, and iV-Aryl-(2,2-dihalo-l-phenylcyclopropyl)methyleneamines to 1-Alkyl-, and l-Aryl-2 (or 3)-halo-4-phenylpyrroles Shinzo Kagabu ...
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... Yeast can reduce the concentrations of juice-and wine-derived aromatic compounds through both metabolic processes (Swiegers and Pretorius 2005) and ... Thank you to Melissa Drouin, Lynda Van Zuiden, Gail Higenell, Amy Blake, Kevin... more
... Yeast can reduce the concentrations of juice-and wine-derived aromatic compounds through both metabolic processes (Swiegers and Pretorius 2005) and ... Thank you to Melissa Drouin, Lynda Van Zuiden, Gail Higenell, Amy Blake, Kevin Ker, Dr Tomas Hudlicky, and Dr Andy ...
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Research Interests: Engineering, Chemistry, Chromatography, Mass Spectrometry, Medicine, and 12 moreBiological Sciences, Analytical, Atmospheric Pressure, Tandem Mass Spectrometry, Gas Chromatography, CHEMICAL SCIENCES, High Resolution, Liquid Chromatography / Electrospray Ionization Mass Spectrometry, Flame Retardant, Liquid Chromatography, Analytical and Bioanalytical Chemistry, and High Sensitivity
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During the course of our studies of in-use chlorinated flame retardants, such as Dechlorane Plus(®) and Dechloranes 602 and 604, blubber of beluga whales from the Canadian Arctic and lake trout and whitefish from the North American Great... more
During the course of our studies of in-use chlorinated flame retardants, such as Dechlorane Plus(®) and Dechloranes 602 and 604, blubber of beluga whales from the Canadian Arctic and lake trout and whitefish from the North American Great Lakes were found to contain two novel dechlorination products of Dechlorane 602 (Dec602). The structures of these compounds were characterized by experiments performed using both gas chromatography-high resolution mass spectrometry and Fourier transform mass spectrometry with a prepared technical mixture of monohydro and dihydroDec602 derivatives. These Dec602 derivatives are analogous to the well-known monohydro and dihydro photochemical degradation products of Mirex. The ratio of the two monohydroDec602 diastereomers varied between Lake Ontario fish and those from the upper lakes, but only one isomer was found in Arctic beluga, indicating that one isomer is either more stable or more bioaccumulative. Dechlorane Plus(®), Dec603, and Dec 604 were not detected in Arctic beluga, but Dec602 and its monohydroDec602 derivative were measured in approximately equal concentrations, ranging from 25 to 300 pg/g lipid. In Great Lakes fish, concentrations of the monohydroDec602 derivatives were also close to those of Dec602, ranging from 2 to 67 ng/g lipid and were greatest in Lake Ontario. This study reports on the first measurements of dechlorane-related compounds in Arctic biota and the first detection of monohydroDec602 degradation products and their accumulation in biota.