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Wu L.,University of Alberta | Sawada J.A.,University of Alberta | Kuznicki D.B.,Maxxam Analytics | Kuznicki T.,University of Alberta | Kuznicki S.M.,University of Alberta
Journal of Radioanalytical and Nuclear Chemistry | Year: 2014

I-129 is a hazardous fission product due to its long half life and ability to bioaccumulate. Silver mordenite has been studied for the removal of I-129 because of its hydrothermal stability arising from a high Si/Al ratio which subsequently limits its silver loading and iodine capacity. Titanosilicate ETS-10 and the sodium nanotitanate ETS-2 were exchanged to over 35 wt % silver and exposed to saturated iodine vapour at 80 °C under dry and humid conditions. The results indicate that the silver on these materials is reactive toward iodine and that the majority of the silver ions are utilized. © 2014, Akadémiai Kiadó, Budapest, Hungary. Source

Liu Y.,University of Waterloo | Liu Y.,Beijing Hua Xia Zhong Fang Biological Technology Co. | Lord H.,University of Waterloo | Lord H.,Maxxam Analytics | And 5 more authors.
Journal of Chromatography A | Year: 2014

Methicillin resistant Staphylococcus aureus (MRSA) is a bacterium that is resistant to many antibiotics. Resistance to methicillin is related to production of penicillin binding protein 2a (PBP2a). The currently presented research involves the development of antibody-linked immunoaffinity solid phase microextraction (SPME) sorbents characterized from several aspects that can identify protein PBP2a. The on-sorbent binding constant Kd of monoclonal anti-PBP2a antibody for its antigen protein PBP2a was determined to be 4×10-10M. This value was obtained on the basis of the binding curve determined by selective extraction of its antigen PBP2a at different concentrations. The concentration of PBP2a captured by immunoaffinity sorbents was as low as 10ng/mL; lower concentrations could not be tested due to the sensitivity limitation of the LC-MS/MS system available. Surface density was estimated at 59ng antibody/cm2. To reduce non-specific binding, especially when the antigen is a protein, bovine serum albumin (BSA) was used to pretreat surfaces. The established immunoaffinity platform technology is expected to provide insights into the development of a practical, specific, sensitive and accurate assay for in vitro and in vivo diagnostics of MRSA. © 2014 Elsevier B.V. Source

Souza-Silva T.A.,University of Waterloo | Jiang R.,Sun Yat Sen University | Rodriguez-Lafuente A.,Maxxam Analytics | Gionfriddo E.,University of Waterloo | Pawliszyn J.,University of Waterloo
TrAC - Trends in Analytical Chemistry | Year: 2015

The present review, the first of a series of three, aims to describe recent developments in solid-phase microextraction (SPME) technology in the fields of environmental analysis applied to complex environmental matrices. We offer the reader an introductory, concise discussion of SPME fundamentals followed by a perspective on the most commonly used sample-preparation methods. We give particular attention to a comparison of the more recent SPME developments. We especially emphasize the development of new devices, such as cold fiber and thin films. We address quantitation in complex environmental matrices in this review with a concise discussion on calibration strategies for SPME methods. © 2015 Elsevier B.V. Source

Goulet R.R.,Canadian Nuclear Safety Commission | Thompson P.A.,Canadian Nuclear Safety Commission | Serben K.C.,Golder Associates | Eickhoff C.V.,Maxxam Analytics
Environmental Toxicology and Chemistry | Year: 2015

Treated effluent discharge from uranium (U) mines and mills elevates the concentrations of U, calcium (Ca), magnesium (Mg), and sulfate (SO4 2-) above natural levels in receiving waters. Many investigations on the effect of hardness on U toxicity have been experiments on the combined effects of changes in hardness, pH, and alkalinity, which do not represent water chemistry downstream of U mines and mills. Therefore, more toxicity studies with water chemistry encountered downstream of U mines and mills are necessary to support predictive assessments of impacts of U discharge to the environment. Acute and chronic U toxicity laboratory bioassays were realized with 6 freshwater species in waters of low alkalinity, circumneutral pH, and a range of chemical hardness as found in field samples collected downstream of U mines and mills. In laboratory-tested waters, speciation calculations suggested that free uranyl ion concentrations remained constant despite increasing chemical hardness. When hardness increased while pH remained circumneutral and alkalinity low, U toxicity decreased only to Hyalella azteca and Pseudokirchneriella subcapitata. Also, Ca and Mg did not compete with U for the same uptake sites. The present study confirms that the majority of studies concluding that hardness affected U toxicity were in fact studies in which alkalinity and pH were the stronger influence. The results thus confirm that studies predicting impacts of U downstream of mines and mills should not consider chemical hardness. Environ Toxicol Chem 2015;34:562-574. © 2014 The Authors. Published by Wiley Periodicals, Inc. © 2014 The Authors. Published by Wiley Periodicals, Inc. on behalf of SETAC. Source

Mollard R.C.,University of Toronto | Wong C.L.,University of Toronto | Luhovyy B.L.,University of Toronto | Luhovyy B.L.,Mount Saint Vincent University | And 3 more authors.
Applied Physiology, Nutrition and Metabolism | Year: 2014

This study investigated whether pulses (chickpeas, yellow peas, navy beans, lentils) have an effect on blood glucose (BG) and appetite following a fixed-size meal 2 h later. Over the following 2 h, all pulses lowered BG area under the curve (AUC) and lentils reduced appetite AUC compared with white bread (p < 0.05). Following the meal, BG was lower after lentils and chickpeas at 150 and 165 min, and AUC was lower after lentils compared with white bread (p < 0.05). © 2014 Published by NRC Research Press. Source

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