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Electrochemiluminescence Detection (electrochemiluminescence + detection)

Distribution by Scientific Domains

Chemistry	66%
Life Sciences	33%

Selected Abstracts

Determination of Reserpine in Urine by Capillary Electrophoresis with Electrochemiluminescence Detection

ELECTROANALYSIS, Issue 3 2004
Weidong Cao
Abstract A fast and sensitive approach to detect reserpine in urine using micellar electrokinetic capillary chromatography with electrochemiluminescence (ECL) of Ru(bpy)32+ detection is described. Using a 25,,m i.d. capillary as separation column, the ECL detector was coupled to the capillary in the absence of an electric field decoupler. Field-amplified injection was used to minimize the effect of ionic strength in the sample and to achieve high sensitivity. In this way, the sample was analyzed directly without any pretreatment. The method was validated for reserpine in the urine over the range of 1×10,6,1×10,4,mol/L with a correlation coefficient of 0.996. The RSD for reserpine at a level of 5,,mol/L was 4.3%. The LOD (S/N=3) was estimated to be 7.0×10,8,mol/L. The average recoveries for 10,,mol/L reserpine spiked in human urine were 94%. [source]

Simultaneous electrochemical and electrochemiluminescence detection for microchip and conventional capillary electrophoresis

ELECTROPHORESIS, Issue 3 2005
Haibo Qiu
Abstract A simultaneous electrochemical (EC) and electrochemiluminescence (ECL) detection scheme was introduced to both microchip and conventional capillary electrophoresis (CE). In this dual detection scheme, tris(2,2'-bipyridyl)ruthenium(II) (Ru(bpy)32+) was used as an ECL reagent as well as a catalyst (in the formation of Ru(bpy)33+) for the EC detection. In the Ru(bpy)32+ -ECL process, Ru(bpy)33+ was generated and then reacted with analytes resulting in an ECL emission and a great current enhancement in EC detection due to the catalysis of Ru(bpy)33+. The current response and ECL signals were monitored simultaneously. In the experiments, dopamine and three kinds of pharmaceuticals, anisodamine, ofloxacin, and lidocaine, were selected to validate this dual detection strategy. Typically, for the EC detection of dopamine with the presence of Ru(bpy)32+, a ,5 times higher signal-to-noise ratio (S/N) can be achieved than that without Ru(bpy)32+, during the simultaneous EC and ECL detection of a mixture of dopamine and lidocaine using CE separation. The results indicated that this dual EC and ECL detection strategy could provide a simple and convenient detection method for analysis of more kinds of analytes in CE separation than the single EC or ECL detection alone, and more information of analytes could be achieved in analytical applications simultaneously. [source]

Determination of galanthamine in Bulbus Lycoridis Radiatae by coupling capillary electrophoresis with end-column electrochemiluminescence detection

JOURNAL OF SEPARATION SCIENCE, JSS, Issue 15 2010
Biyang Deng
Abstract A novel method for the determination of galanthamine (GAL) in Bulbus Lycoridis Radiatae has been developed based on coupling CE with an end-column tris(2,2,-bipyridyl)ruthenium(II) electrochemiluminescence (ECL). Parameters affecting CE separation and ECL detection were investigated and optimized. Baseline separation of GAL from other components in the Bulbus Lycoridis Radiatae sample was achieved with an 18,mmol/L phosphate running buffer at pH 9.0. Under the optimized conditions: 12,kV CE-separation voltage, ECL detection potential at 1.25,V with 5,mmol/L and 50,mmol/L phosphate buffer at pH 7.5 in the detection reservoir, the linear range of GAL concentration was from 0.8,ng/mL to 2,,g/mL, whereas the detection limit was 0.25,ng/mL (S/N=3). The proposed method was successfully demonstrated for the determination of GAL in Bulbus Lycoridis Radiatae. [source]

Flow injection analysis of tetracyclines using inhibited Ru(bpy)32+/tripropylamine electrochemiluminescence system

LUMINESCENCE: THE JOURNAL OF BIOLOGICAL AND CHEMICAL LUMINESCENCE, Issue 1 2005
Yong-Qiang Pang
Abstract Tetracyclines (TCs) were found to strongly inhibit the electrochemiluminescence (ECL) from the Ru(bpy)32+,tripropylamine system when a working Pt electrode was maintained at 1.05 V (vs. Ag[sol ]AgCl) in pH 8.0 carbonate buffer solution. On this basis, a flow injection (FI) procedure with inhibited electrochemiluminescence detection has been developed for the determination of tetracycline (TC) and oxytetracycline (OTC). Under the optimized condition, the linear ranges of 2.0 × 10,8,1.0 × 10,5 and 1.0 × 10,8,1.0 × 10,5 g[sol ]mL and the detection limits of 4.0 × 10,9 and 3.8 × 10,9 g[sol ]mL were obtained for TC and OTC, respectively. The relative standard deviations (RSD) were 0.68% and 1.18% for 5.0 × 10,7 g[sol ]mL TC and OTC (n = 13), respectively. The method showed higher sensitivity than most of the reported methods. It was successfully applied to the determination of tetracycline in a Chinese proprietary medicine, Tetracyclini and Cortisone Eye Ointment, and the residues of tetracycline in honey products. The inhibition mechanism has been proposed due to an energy transfer between electrogenerated Ru(bpy)32+* and benzoquinone derivatives at the electrode surface. Copyright © 2005 John Wiley & Sons, Ltd. [source]

CSF amyloid-, 1-38 and 1-42 in FTD and AD: Biomarker performance critically depends on the detergent accessible fraction

PROTEOMICS - CLINICAL APPLICATIONS, Issue 10-11 2008
Mirko Bibl Dr.
Abstract Cerebrospinal fluid (CSF) A,1-38, A,1-40, and A,1-42 were comparatively analyzed by amyloid-beta SDS-PAGE with Western immunoblot (A,-SDS-PAGE/immunoblot), electrochemiluminescence detection and ELISA (MSD/ELISA) in patients with Alzheimer's disease (AD, n,=,40), frontotemporal dementia (FTD, n,=,30), and other dementias (n,=,50) and nondemented disease controls (n,=,30). CSF A,-peptide concentrations were higher and selective decreases of CSF A,1-38 in FTD and A,1-42 in AD were more evident as measured after SDS-denaturizing of samples by A,-SDS-PAGE/immunoblot. The SDS-accessible pool of CSF A,1-38 and A,1-42, represented by the individual gain of A,-peptide yield using A,-SDS-PAGE/immunoblot, was reduced in both FTD and AD. Accordingly, biomarker accuracies of A,1-38 and A,1-42 for detection of FTD and AD, respectively declined as determined by MSD/ELISA. We conclude that a pool of CSF A,1-38 and A,1-42, which shows disease-specific reductions in FTD and AD, may be bound to carriers and can be released by SDS. Assessing this SDS-accessible A,-peptide pool may crucially enhance the accuracy of CSF biomarker tests. Identifying disease-specific binding properties of affected A, carriers may elucidate pathogenic aspects and open up a novel field for therapeutic approaches. [source]

Simultaneous determination of methylephedrine and pseudoephedrine in human urine by CE with electrochemiluminescence detection and its application to pharmacokeinetics

BIOMEDICAL CHROMATOGRAPHY, Issue 11 2009
Yan-Ming Liu
Abstract A novel method for the determination of ephedra alkaloids (methylephedrine and pseudoephedrine) was developed by electrophoresis capillary (CE) separation and electrochemiluminesence detection (ECL). The use of ionic liquid (1-butyl-3-methylimidazolium tetrafluoroborate, BMIMBF4) improved the detection sensitivity markedly. The conditions for CE separation, ECL detection and effect of ionic liquid were investigated in detail. The two ephedra alkaloids with very similar structures were well separated and detected under the optimum conditions. The limits of detection (signal-to-noise ratio = 3) in standard solution were 1.8 × 10,8 mol/L for methylephedrine (ME) and 9.2 × 10,9 mol/L for pseudoephedrine (PSE). The limits of quantitation (signal-to-noise ratio = 10) in human urine samples were 2.6 × 10,7 mol/L for ME and 3.6 × 10,7 mol/L for PSE. The recoveries of two alkaloids at three different concentration levels in human urine samples were between 81.7 and 105.0%. The proposed method was successfully applied to the determination of ME and PSE in human urine and the monitoring of pharmacokinetics for PSE. The proposed method has potential in therapeutic drug monitoring and clinical analysis. Copyright © 2009 John Wiley & Sons, Ltd. [source]