Browsing by Author "Lin, Kuan-Wen"

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1-Butyl-3-methylimidazolium-based ionic liquids and an anionic surfactant: Excellent background electrolyte modifiers for the analysis of benzodiazepines through capillary electrophoresis
(2010-04-23)
Su, Hsiu-Li
;
Kao, Wan-Chun
;
Lin, Kuan-Wen
;
Lee, Cheng-yu
;
Hsieh, You-Zung
In this study, we found that adding 1-butyl-3-methylimidazolium-based ionic liquids (ILs) and sodium dodecyl sulfate (SOS) as modifiers in the background electrolyte (BGE) for capillary electrophoresis enhanced the separation of benzodiazepines. In particular, 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([BMIM][NTf(2)]) was the best IL additive for the separation system because its anionic moiety interacted favorably with the benzodiazepines. We added SDS because of its known effect on the separation of hydrophobic analytes. We optimized the separation conditions in terms of the concentrations of the IL, SOS, and organic solvent, the pH, and the BGE's ionic strength. The optimal BGE, containing 170 mM [BMIM][NTf(2)] and 10 mM SOS, provided baseline separation, high efficiency, and satisfactory peak shapes for the benzodiazepines. The separation mechanism was based on heteroassociation between the anionic moiety of the IL and the benzodiazepines, with SOS improving the resolution of the separation. The limits of detection for the seven analytes ranged from 2.74 to 4.42 mu g/mL. We subjected a urine sample to off-line solid phase extraction (SPE) prior to the analysis of its benzodiazepine content. Our experimental results reveal that the combination of [BMIM][NTf(2)] and SDS provides adequate separation efficiency for its application to CE analyses of benzodiazepines after SPE concentration. (C) 2010 Elsevier B.V. All rights reserved.
Electrooxidation of catecholamines at carbon nanotube-modified indium tin oxide electrodes
(2008-06-30)
Lin, Kuan-Wen
;
Lin, Chang-Hao
;
Hsieh, You-Zung
;
應用化學系
;
Department of Applied Chemistry
In this study, we prepared carbon nanotube (CNT)/Nafion-modified ITO electrodes and investigated their electrochemical behavior. The CNTs were dissolved in a solution of the ionic polymer Nafion and then CNT/Nafion composite films were deposited onto ITO electrodes through spin-coating of this homogeneous solution. We studied the effects of chemical pretreatment of the CNTs and the pH of the buffer on the electroanalytical behavior of the CNT/Nafion-modified ITO electrodes toward catecholamines. The modified electrodes enhanced the peak current and lowered the overpotentials. We observed high electrooxidative performance for the modified ITO electrodes: the oxidative currents of the catecholamines were up to 125-fold higher than those obtained using bare ITO electrodes. (C) 2008 Elsevier B.V. All rights reserved.
Glucose sensing by electrochemically grown copper nanobelt electrode
(2009-11-15)
Huang, Ting-Kai
;
Lin, Kuan-Wen
;
Tung, Sze-Ping
;
Cheng, Ta-Ming
;
Chang, I-Chun
A simple design of growing Cu nanobelt (NB) electrode for glucose sensing is presented. Cu NBs were grown directly on carbon electrodes by using electrochemical deposition. The average width, thickness and length of the NBs were about 50 nm, 20 nm and several tens of micrometers, respectively. Cyclic voltammetric (CV) experiments showed that a Cu NB electrode grown by a reduction charge of 0.5 C on a substrate of 0,018 cm(2) enhanced glucose oxidation ability. For glucose sensing, the electrode exhibited a high sensitivity of 79.8 mu A/mM and a measurable detection limit of 10 mu M in amperometric detection. (C) 2009 Elsevier B.V. All rights reserved.
In-channel simplified decoupler with renewable electrochemical detection for microchip capillary electrophoresis
(2008-06-30)
Lin, Kuan-Wen
;
Huang, Yan-Kai
;
Su, Hsiu-Li
;
Hsieh, You-Zung
;
應用化學系
Electrochemical (EC) detection is comparable to fluorescence detection in that it is simple to perform, economical, and highly sensitive. In this study, we used replica molding to fabricate a PDMS microchip for microchip capillary electrophoresis (CE). A decoupler electrode and a working electrode were implanted into the PDMS chip during the molding process to prevent leakage into the electrode channel. The working electrode could be renewed readily through its slight withdrawal (ca. 3 mm) from the PDMS; its detection ability was highly reproducible in the microchip CE-EC system. The relative standard deviation (R.S.D.) of the detecting current for the renewed working electrode was 1.2% (n = 5). The calibration curves were linear for both dopamine and catechol analytes over the concentration range 10-1000 mu M, with coefficients ofdetermination (R-2) of 0.999 and 0.976, respectively. The number of theoretical plates (N/m) for these analytes was greater than 133,000. (C) 2008 Elsevier B.V. All rights reserved.
The equilibrium contract rent and reward money under incomplete information in reverse supply chains: A game theoretical approach and computational study
(2016-12)
Hong, I-Hsuan
;
Dang, Jr-Fong
;
Lin, Kuan-Wen
;
工業工程與管理學系
;
Department of Industrial Engineering and Management
Many electronic end-of-life (EOL) products are becoming obsolete sooner due to advances in technology. Hence, manufacturers hire third-party recyclers as subcontractors to recycle brand-name products. A complicated profile of recycling EOL products adds a significant cost burden to the third-party recyclers, while only the manufacturer has a superior understanding of the profile of recycling EOL products (homogeneity degree of EOL products). This paper describes the decision of the manufacturer and the third-party recycler in reverse supply chains under incomplete information of product homogeneity, which affects the unit profit of recycled products. The supply chain model assumes that customers receive reward money for returning obsolete products, and that the manufacturer as a leader and the third-party recycler as a follower determine the contract rent offered to the third-party recycler and the reward money paid to customers, respectively. Both the manufacturer and third-party recycler want to maximize their profit functions. We propose a game theoretical approach to search for the equilibrium contract rent for the third-party recycler and the equilibrium reward money for customers returning products for recycling. We conclude with a discussion of the impact of the contract rent and reward money on the equilibrium solution. (C) 2016 Published by Elsevier Ltd.