The Experts below are selected from a list of 81 Experts worldwide ranked by ideXlab platform
Lung-ming Fu - One of the best experts on this subject based on the ideXlab platform.
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Electrophoresis separation and electrochemical detection on a novel thread-based microfluidic device
Microfluidics and Nanofluidics, 2013Co-Authors: Lung-ming FuAbstract:This paper describes a thread-based microfluidic system for rapid and low-cost electrophoresis separation and electrochemical (EC) detection of ion samples. Instead of using liquid channel for sample separation, thin polyester threads of various diameters are used as the routes for separating the samples with electrophoresis. Hot-pressed PMMA chip with protruding sleeper structures are adopted to set up the polyester threads and for electrochemical detection of the ion samples on the thread. Plasma treatment greatly improves the wetability of thin threads and surface quality of the threads. The measured electrical currents on plasma treated threads are 10 times greater than the threads without treatment. Results indicate that nice redox signals can be obtained by measuring ferric Cyanide Salt on the polyester thread. The estimated detection limit for EC sensing of potassium ferriCyanide (K3Fe(CN)6) is around 6.25 μM using the developed thread-based microfluidic device. Mixed ion samples (Cl−, Br− and I−) and bio-sample are successfully separated and detected using the developed thread-based microfluidic device.
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Electrophoresis separation and electrochemical detection on a novel thread-based microfluidic device
Microfluidics and Nanofluidics, 2013Co-Authors: Lung-ming FuAbstract:This paper describes a thread-based microfluidic system for rapid and low-cost electrophoresis separation and electrochemical (EC) detection of ion samples. Instead of using liquid channel for sample separation, thin polyester threads of various diameters are used as the routes for separating the samples with electrophoresis. Hot-pressed PMMA chip with protruding sleeper structures are adopted to set up the polyester threads and for electrochemical detection of the ion samples on the thread. Plasma treatment greatly improves the wetability of thin threads and surface quality of the threads. The measured electrical currents on plasma treated threads are 10 times greater than the threads without treatment. Results indicate that nice redox signals can be obtained by measuring ferric Cyanide Salt on the polyester thread. The estimated detection limit for EC sensing of potassium ferriCyanide (K3Fe(CN)6) is around 6.25 μM using the developed thread-based microfluidic device. Mixed ion samples (Cl−, Br− and I−) and bio-sample are successfully separated and detected using the developed thread-based microfluidic device.
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Retraction Note: Electrophoresis separation and electrochemical detection on a novel thread-based microfluidic device
Microfluidics and Nanofluidics, 2013Co-Authors: Lung-ming FuAbstract:This article describes a thread-based microfluidic system for rapid and low-cost electrophoresis separation and electrochemical (EC) detection of ion samples. Instead of using liquid channel for sample separation, thin polyester threads of various diameters are used as the routes for separating the samples with electrophoresis. Hot-pressed PMMA chip with protruding sleeper structures are adopted to set up the polyester threads and for electrochemical detecting the ion samples on the thread. Plasma treatment greatly improves the wetability of thin threads and surface quality of the threads. The measured electrical currents on plasma-treated threads are ten times greater than the threads without treatment. Results indicate that nice redox signals can be obtained by measuring ferric Cyanide Salt on the polyester thread. The estimated detection limit for EC sensing of potassium ferriCyanide (K3Fe(CN)6) is around 6.25 μM using the developed thread-based microfluidic device. Mixed-ion samples (Cl−, Br−, and I−) and bio-sample are successfully separated and detected using the developed thread-based microfluidic device.
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RETRACTED ARTICLE: Electrophoresis separation and electrochemical detection on a novel thread-based microfluidic device
Microfluidics and Nanofluidics, 2013Co-Authors: Lung-ming FuAbstract:This article describes a thread-based microfluidic system for rapid and low-cost electrophoresis separation and electrochemical (EC) detection of ion samples. Instead of using liquid channel for sample separation, thin polyester threads of various diameters are used as the routes for separating the samples with electrophoresis. Hot-pressed PMMA chip with protruding sleeper structures are adopted to set up the polyester threads and for electrochemical detecting the ion samples on the thread. Plasma treatment greatly improves the wetability of thin threads and surface quality of the threads. The measured electrical currents on plasma-treated threads are ten times greater than the threads without treatment. Results indicate that nice redox signals can be obtained by measuring ferric Cyanide Salt on the polyester thread. The estimated detection limit for EC sensing of potassium ferriCyanide (K_3Fe(CN)_6) is around 6.25 μM using the developed thread-based microfluidic device. Mixed-ion samples (Cl^−, Br^−, and I^−) and bio-sample are successfully separated and detected using the developed thread-based microfluidic device.
Robert J. Wells - One of the best experts on this subject based on the ideXlab platform.
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Direct on-column derivatisation in gas chromatography. II. Comparison of various on-column methylation reagents and the development of a new selective methylation reagent
Journal of Chromatography A, 1996Co-Authors: Masooma Amijee, Julie Cheung, Robert J. WellsAbstract:It has been demonstrated that judicious choice of the derivatisation reagent used for direct on-column methylations can have a profound effect of the products produced, often with little effect on the overall methylation efficiency of the process. Trimethylsulfonium acetate, trimethylsulfonium Cyanide and phenyltrimethylammonium acetate are three new selective methylation reagents for direct on-column derivatisation in gas chromatography. Phenyltrimethylammonium acetate is a particularly stable, selective and efficient new direct on-column methylation reagent. This work demonstrates that, for routine on-column methylation where no selectivity is required, phenyltrimethylammonium fluoride (PTMA-F) is as efficient as phenyltrimethylammonium hydroxide. PTMA-F is the preferred reagent because it is neutral and produces less column deterioration than the hydroxide. Where methylation selectivity is required, both phenyltrimethylammonium acetate has very similar efficiency and selectivity as the previously reported Cyanide Salt. However, the acetate is the more stable and readily utilised than the Cyanide and is the best of a number of selective on-column methylation reagents surveyed in this work.
Christian Brückner - One of the best experts on this subject based on the ideXlab platform.
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Why Is There Cyanide in my Table Salt? Structural Chemistry of the Anticaking Effect of Yellow Prussiate of Soda (Na4[Fe(CN)6]·10H2O)
Journal of Chemical Education, 2015Co-Authors: Sarina J. Dorazio, Christian BrücknerAbstract:Yellow Prussiate of Soda (YPS, Na4[Fe(CN)6]·10H2O) is an approved anticaking agent in table Salt. Given that it is a Cyanide Salt, its use as a food additive is surprising. Recent findings on the mode of action of submonoatomic layers of YPS on NaCl crystals to act as an anticaking agent through nucleation inhibition are presented and its low toxicity is rationalized. The molecular mechanics of the anticaking action are relatively easy to understand for students in general chemistry or sophomore inorganic courses as they involve the archetypal cubic sodium chloride crystal structure and simple steric and electrostatic arguments. The molecular-level explanation reinforces the notion of how structure and charge affect the properties of matter and may also serve as entry toward a classroom dialogue of how ionic lattices are formed. A simple naked eye analytical method of detecting YPS on store-bought table Salt in the form of the pigment Prussian Blue (Fe4[Fe(CN)6]3·xH2O) can be utilized as a related demonst...
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why is there Cyanide in my table Salt structural chemistry of the anticaking effect of yellow prussiate of soda na4 fe cn 6 10h2o
Journal of Chemical Education, 2015Co-Authors: Sarina J. Dorazio, Christian BrücknerAbstract:Yellow Prussiate of Soda (YPS, Na4[Fe(CN)6]·10H2O) is an approved anticaking agent in table Salt. Given that it is a Cyanide Salt, its use as a food additive is surprising. Recent findings on the mode of action of submonoatomic layers of YPS on NaCl crystals to act as an anticaking agent through nucleation inhibition are presented and its low toxicity is rationalized. The molecular mechanics of the anticaking action are relatively easy to understand for students in general chemistry or sophomore inorganic courses as they involve the archetypal cubic sodium chloride crystal structure and simple steric and electrostatic arguments. The molecular-level explanation reinforces the notion of how structure and charge affect the properties of matter and may also serve as entry toward a classroom dialogue of how ionic lattices are formed. A simple naked eye analytical method of detecting YPS on store-bought table Salt in the form of the pigment Prussian Blue (Fe4[Fe(CN)6]3·xH2O) can be utilized as a related demonst...
Masooma Amijee - One of the best experts on this subject based on the ideXlab platform.
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Direct on-column derivatisation in gas chromatography. II. Comparison of various on-column methylation reagents and the development of a new selective methylation reagent
Journal of Chromatography A, 1996Co-Authors: Masooma Amijee, Julie Cheung, Robert J. WellsAbstract:It has been demonstrated that judicious choice of the derivatisation reagent used for direct on-column methylations can have a profound effect of the products produced, often with little effect on the overall methylation efficiency of the process. Trimethylsulfonium acetate, trimethylsulfonium Cyanide and phenyltrimethylammonium acetate are three new selective methylation reagents for direct on-column derivatisation in gas chromatography. Phenyltrimethylammonium acetate is a particularly stable, selective and efficient new direct on-column methylation reagent. This work demonstrates that, for routine on-column methylation where no selectivity is required, phenyltrimethylammonium fluoride (PTMA-F) is as efficient as phenyltrimethylammonium hydroxide. PTMA-F is the preferred reagent because it is neutral and produces less column deterioration than the hydroxide. Where methylation selectivity is required, both phenyltrimethylammonium acetate has very similar efficiency and selectivity as the previously reported Cyanide Salt. However, the acetate is the more stable and readily utilised than the Cyanide and is the best of a number of selective on-column methylation reagents surveyed in this work.
Veena Sahajwalla - One of the best experts on this subject based on the ideXlab platform.
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A Novel Recycling Approach for Transforming Waste Printed Circuit Boards into a Material Resource
Procedia Environmental Sciences, 2014Co-Authors: Rita Khanna, R. Cayumil, P.s. Mukherjee, Veena SahajwallaAbstract:Abstract The recovery of materials from urban waste has become progressively more important with wastes providing a variety of resources. This study focuses on the recycling of electronic printed circuit boards (PCBs) from mobile phones, computers, TVs, white goods, and micro-processors etc. that contain significant amounts of hazardous/toxic components along with a variety of metals, ceramics and polymers. Both formal and informal sectors are engaged worldwide in recycling such e-waste to recover precious and other metals (upto 40-70% of value). However poor recycling techniques, especially in developing countries, generate high levels of environmental pollution that affects both the ecosystems and the people living within or near the main recycling areas. Various e-waste recycling methods used in the informal sector include manual dismantling, open burning of PCBs, plastic chipping and melting, burning wires to recover copper, acid & Cyanide Salt leaching, and inadequate metallurgical treatments. These activities release dust particles loaded with heavy metals and flame retardants into the atmosphere that may re-deposit near the emission site, or be transported over long distances depending on their size. Significant levels of environmental pollution are thus associated with recycling e-waste. This study presents an environmentally sustainable solution to e-waste management and reducing associated pollution during recycling. In this study, waste PCBs were heat treated in the temperature range 1150-1350 o C for periods of up to 20 minutes in an Argon atmosphere. Key metallic constituents namely Cu, Sn and Pb showed a tendency to segregate out in the form of copper rich and Sn rich metallic balls. Minor elements such as Al, Fe, Mg, Ni, Pd, Pt and Zn segregated along with metallic droplets. Such high temperatures led to the removal of hazardous lead and the recovery of highly concentrated copper alloys and precious metals. Pyrolysis of PCBs also generated a carbon rich residue containing traces of Sn and very low levels of copper. Various ceramic impurities present precipitated out as slag and did not interfere with metal recovery.
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Urban Environmental Pollution 2013 - Creating Healthy, Livable Cities A novel recycling approach for transforming waste printed circuit boards into a material resource
2014Co-Authors: Rita Khanna, R. Cayumil, Veena SahajwallaAbstract:The recovery of materials from urban waste has become progressively more important with wastes providing a variety of resources. This study focuses on the recycling of electronic printed circuit boards (PCBs) from mobile phones, computers, TVs, w hite goods, and micro-processors etc. that contain sig nificant amounts of hazardous/toxic components along with a variety of metals, ceramics and polymers. Both formal and informal sectors are engaged worldwide in recycling such e-waste to recover p recious and other metals (upto 40-70% of value). However poor recycling techniques, especially in developing countries, g enerate high levels of environmental pollution that affects both the ecosystems and the people living within or near the main rec ycling areas. Various e-waste recycling methods used in the informal sector include manual dismantling, open burning of P CBs, plastic chipping and melting, burning wires to recover copper, acid & Cyanide Salt leaching, and inadequate metallurgical treatments. These activities release dust particles loaded with heavy metals and flame retardants into the atmosphere that may redeposit near the emission site, or be transported over lo ng distances depending on their size. Significant levels of environmental pol lution are thus associated with recycling e-waste. This study presents an environmentally sustainable solution to e-waste management and reducing associated pollution during rec ycling. In this study, waste PCBs were heat treated in the temperature range 1150-1350°C for periods of up to 20 minutes in a n Argon atmosphere. Key metallic constituents namely Cu, Sn and Pb showed a tendency to segregate out in the form of copper rich and Sn rich metallic balls. Minor elements such as Al, Fe, Mg, Ni, Pd, Pt and Zn segregated along with metallic droplets. Such high temperatures led to the removal of hazardous l ead and the recovery of highly concentrated copper alloys and precious metals. Pyrolysis of PCBs also generated a carbon rich residue containing traces of Sn and very low levels of copper. Various ceramic impurities present precipitated out as slag and did not interfere with metal recovery. © 2014 The Authors. Published by Elsevier B.V. Selection and peer review under the responsibility and editorial leadership of Guest Editor Dr. Art Chappelka.
