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Stuart Chalk, Ph.D.
Department of Chemistry
University of North Florida
Phone: 1-904-620-1938
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Chinese Journal of Chemistry

  • Publisher: Wiley
  • FAD Code: CJOC
  • CODEN: CJOCEV
  • ISSN: 1001-604X
  • Abbreviation: Chin. J. Chem.
  • DOI Prefix: 10.1002/cjoc
  • Other Name(s): Acta Chimica Sinica (English Ed)
  • Language: Chinese,English
  • Comments: Fulltext from 2005 V24 on wiley

Citations 12

"A Study On The Interaction Of The DAS-K With Bovine Serum Albumin By On-line Ultrafiltration And Chemiluminescence"
Chin. J. Chem. 2006 Volume 24, Issue 12 Pages 1777-1783
Yan-Tu Zhang, Zhu-Jun Zhang, Yong-Hua Sun

Abstract: Potassium dehydroandrographolide succinate (DAS-K) has antibacterial and antiviral effects. It has been used widely for the treatment of virus pneumonia, malaria and respiratory infections. In this work, a novel flow-injection chemiluminescence (CL) method for the determination of DAS-K was proposed. The method is based on the reaction between DAS-K and hexacyanoferrate(III) in alkaline solution to give weak CL signal, which is enhanced by rhodamine B. The experimental conditions for the CL reaction were optimized and the possible reaction mechanism was discussed. Under the optimum conditions, the concentration of DAS-K is proportional to the CL intensity in the range of 0.1-80 µmol L-1 with a detection limit of 0.05 µmol L-1. The interaction of the DAS-K with bovine serum albumin by on-line ultrafiltration and flow-injection chemiluminescence was studied. The concentrations of unbound DAS-K from ultra filter tube were determined by the flow-injection CL method. The binding parameters were estimated by the Scatchard plot and Klotz plot. The proposed system proved that FIA-CL coupled with on-line ultrafiltration sampling was a fast and simple technique for the study of drug-protein interaction.

"Preparation Of Nanosized CoHCF Modified Electrode And Its Application To Electroanalysis Of Hemoglobin"
Chin. J. Chem. 2005 Volume 23, Issue 8 Pages 983-989
Liu Mei-Chuan, Li Ping, Zhang Li, Xian Yue-Zhong, Ding Hong-Chun, Zhang Cheng-Lin, Zhang Fen-Fen, Jin Li-Tong

Abstract: A cobalt hexacyanoferrate (CoHCF) nanoparticle (size ~60 nm) chemically modified electrode (CME) was fabricated and the electrochemical behavior of hemoglobin (Hb) at this nanosized CoHCF CME was studied. In comparison with a bare glassy carbon electrode (GCE) and a general CoHCF CME electrodeposited in a traditional manner, the present nanosized CoHCF CME performed efficiently electrocatalytic reduction for Hb with relatively high sensitivity, stability, and longlife. Combined with liquid chromatography (LC), the nanosized CoHCF CME was used as the electrochemical detector of Hb in the established flow injection analysis-electrochemical determination (FIA-ECD) system. The peak current was a linear function of concentrations in the range from 2.5 x 10^-8 to 5.0 x 10^-6 mol/L for Hb, with detection limit of 1.4 x 10^-8 mol/L. The FIA-ECD system has been successfully applied to assess the Hb content of clinic blood samples with advantages of sensitiveness, speediness, easy control and small sample-consumption.

"Simultaneous Monitoring Of Glucose, Lactate And L-Glutamate In Rat Blood By A Flow-injection Enzyme Electrode Array System"
Chin. J. Chem. 2005 Volume 23, Issue 3 Pages 280-284
Wan Qiao, Zhang Fen-Fen, Liu Mei-Chuan, Zhu Zi-Qiang, Xian Yue-Zhong, Jin Li-Tong

Abstract: Rapid measurement of glucose, lactate and L-glutamate level in blood is important for studying the balance of energy in body. The flow-injection analysis (FIA) system with enzyme electrode array was based on neutral red-doped silica (NRDS) nanoparticles as electrocatalyst. These uniform NRDS nanoparticles (about 50±3 nm) were prepared by a water-in-oil (W/O) microemulsion method, and characterized by TEM technique. The doped in-side neutral red maintained its high electron-activity, while the outside nano silica surface prevented neutral red from leaching out into the aqueous solutions and showed high biocompability. These nanoparticles were then mixed with the glucose oxidase (GOD), lactate oxidase (LOD) or L-glutamate oxidase (L-GLOD), and immobilized on a three carbon-disk electrode (CE) array, respectively. A thin Nafion film was coated on the enzyme layer to prevent interference such as ascorbic acid and uric acid in the blood. The proposed flow-injection analysis with NRDS-enzyme electrode array method enables simultaneously monitoring various levels of glucose, lactate and L-glutamate in blood.

"Fabrication Of ZnO Nanorod Modified Electrode And Its Application To The Direct Electrochemical Determination Of Hemoglobin And Cytochrome C"
Chin. J. Chem. 2005 Volume 23, Issue 2 Pages 144-148
Zhang Cheng-Lin, Liu Mei-Chuan, Li Ping, Xian Yue-Zhong, Cheng Yu-Xiao, Zhang Fen-Fen, Wang Xiao-Li, Jin Li-Tong

Abstract: A novel electrochemical method as a sensitive and convenient technique for the determination of heme proteins based on their interaction with ZnO nanorods was developed. A ZnO nanorod modified glassy carbon electrode (ZnO/GCE) was prepared and the electrochemical behaviors of heme proteins, such as hemoglobin (HB) and cytochrome c (Cyt-c), on this modified electrode have been studied. The results showed that both HB and Cyt-c could be oxidized on the modified electrode and the oxidation currents were linear to the concentrations of the analytes in aqueous solutions. In addition, the results of flow injection analysis (FIA) further suggested the high stability and reproducibility of the ZnO nanorod modified electrode. So this method can be applied to the determination of HB and Cyt-c in biological systems.

"Flow Injection Chemiluminescence Sensor For The Determination Of Gallic Acid By Immobilizing Luminol And Periodate On Anion-exchange Resin"
Chin. J. Chem. 2002 Volume 20, Issue 10 Pages 1049-1054
ZHANG, Si-Chun, ZHOU, Guo-Jun, JU, Huang-Xian

Abstract: A novel chemiluminescence (CL) sensor for the determination of gallic acid combined with flow injection analysis was developed by electrostatically immobilizing luminol and periodate on anion-exchange resins respectively. Gallic acid was sensed by its enhancing effect on the weak CL reaction between luminol. and periodate, which were eluted from the ion exchange column. The possible reaction mechanism of the CL system was suggested and discussed. The response of the sensor to gallic acid concentration was linear over the range of 8.0 x 10^-9-1.0 x 10^-6 mol/L with a detection limit of 6.5 x 10^-9 mol/L (3s). The relative standard deviation (RSD) for 7 repetitive determinations of gallic add (1.0 x 10^-7 mol/L) was 1.8%. The sensor could be used for over 400 times determination with a good reproducibility.

"Application Of Nafion/cobalt Hexacyanoferrate Chemically Modified Electrodes For The Determination Of Electroinactive Cations By Ion Chromatography"
Chin. J. Chem. 2002 Volume 20, Issue 8 Pages 771-776
XU, Ji-Ming,XIAN, Yue-Zhong,SHI, Guo-Yue,LI, Jin-Hua, Jin, Li-Tong

Abstract: An amperometric detector based on the chemical modification of Nafion and cobalt (II) hexacyanoferrate (II, III) thin Mm (Nafion/Co-CN-Fe) onto a glassy carbon (GC) electrode was firstly developed for the determination of electroinactive cations (Li+, Na+, K+, Rb+, Cs+ and NH4+) in single column ion chromatography. A set of well-defined peaks of electroinactive cation was obtained. The relative standard deviations (RSDs) of chromatographic peak height (nA) for these cations were all below 3.8%. The cations were detected conveniently in the linear concentration range of 6.0 x 10^-6-5.0 x 10^-3 mol/L and their correlation coefficients were all above 0.99. The detection limits of the cations were 9.2 x 10^-6 mol/L for Li+, 3.4 x 10^-6 mol/L for Na+, 6.3 x 10^-7 mol/L for K+, 7.8 x 10^-7 mol/L for Rb+, 6.2 x 10^-7 mol/L for Cs+ and 6.2 x 10^-6 mol/L for NW, at a signal-noise ratio of 3. The method was quick, sensitive, simple and was successfully applied to the analysis of rainwater samples. The electrode was stable for a 2 week period of operation with no evidence of chemical or mechanical deterioration.

"Electrochemiluminescent Behaviour Of Vitamin B-1 (thiamine) And Tris(2,2 -bipyridyl) Ruthenium In A Flow System"
Acta Chim. Sin. 2000 Volume 58, Issue 5 Pages 563-566
CHEN Xi*,CHEN Wei,WANG Xiao-Ru

Abstract: Upon the electrochemical oxidation of tris(2,2 - bipyridyl) ruthenium(II) [Ru(bpy)(3)(2+)] and vitamin Bl(thiamine) in 0.1 mol/L NaOH (aqueous solution), a bright electrochemiluminescence (ECL) was observed. Vitamin B1 was transformed into a yellow pseudo - base and a colorless thiol formed when treated with 0.1 mol/L NaOH for 5 and 20 min, respectively. The thiol form was oxidized at + 0.88 V (vs.Ag/AgCl) to produce a free radical, which reacted with Ru(bpy)(3)(3+) at a glassy carbon electrode. The light emission at wavelength 609 nm was caused by the transition of the excited state of Ru(bpy)(3)(2+) to its ground state. The pH of solution effected the hydrolysis of vitamin B1, which caused the different light emission intensity of Ru(bpy)(3)(2+) and vitamin B1 solution. ECLs of some coexisting substances such as amino acids, sugars, hydroxyl carboxylic acids, vitamin Bz, Bg were also detected in this now system.
Vitamin B1 Tris(bipyridine)ruthenium(II) chloride Chemiluminescence

"Chemiluminescence Biosensor For Determination Of Acetylcholine And Choline"
Acta Chim. Sin. 1998 Volume 56, Issue 12 Pages 1207-1213
Song Zhenghua; Zhang Zhujun; Fan Wenzhe

Abstract: A chemiluminescence (CL) biosensor responding to acetylcholine (ACh) and choline (Ch) was prepared by covalently coupling acetylcholinesterase (AChE) and choline oxidase (ChO) to the controlled pore glass as a molecular recognition element, using electrostatically immobilizing luminol and copper ion exchange resin as a transduction element in a flow injection system. The analytes were injected into a continuous stream of simple medium flowing through a sequence of enzyme reactors containg AChE and ChO to produce hydrogen peroxide. The luminol and Cu2+ were eluted by Na2SO4 from the ion exchange resin column, then reacted with hydrogen peroxide to produce CL. The linear range for both the ACh and Ch was 1-1000 pmol, the detection limit was 500 fmol. A complete analysis can be finished within 2 min. The sensor was stable for six months and has been applied successfully to the analysis of ACh and Ch in human serum and rat brain.
Acetylcholine Choline Chemiluminescence Sensor

"New Chemiluminescence Reaction System For Analysis Of Polyhydroxy-compounds Determination Of Uric-acid In Urine"
Acta Chim. Sin. 1997 Volume 55, Issue 8 Pages 806-810
FENG MANLIANG;HUANG YUWEN;ZHANG ZHUJUN

Abstract: A novel flow injection chemiluminescence method for the determination of polyhydroxy - compounds was described. The method is based on that polyhydroxy - compounds enhance the CL reaction of luminol with K-7 in potassium hydroxide medium. In the experiments, luminescent reagent-luminol was injected in order to keep the baseline steady and save reagents,especially,to improve sensitivity. The method was used in measuring uric acid in urine and it allows quantitation of uric acid concentration in the 2 x 10^-8 similar to 1 x 10^-6 g/mL range with a detection limit of 7.2 x 10^-9 g/mL. RSD = 2.04%. 8 References
Uric acid Urine Chemiluminescence Sensitivity

"Studies On Flow Injection Chemiluminescence Immunoassay. 2. Hetermination Of HRP And Its Conjugates With Coupled Reaction"
Acta Chim. Sin. 1997 Volume 55, Issue 6 Pages 590-594
Shao Qian; Ma Wangbai; Feng Manliang; Zhang Zhujun

Abstract: In this paper chitoson, controlled pore glass and silica - gel have been investigated with respect to its potentiality of being used as solid support of flow - injection immunoassay. A new flow - injection immunoassay end - point detection method has also been developed on the basis of coupling the reaction of H2O2 and K4Fe(CN)(6), catalyzed by HRP, with H2O2 and K3Fe(CN)(6) co - oxidized chemiluminescence reaction of luminol. As enzymatic and chemiluminescent reaction were generated at different sites of the detection system. The general shortcomings of such as unable to select a optimum pH for both enzymatic and chemiluminescent reaction, incomplete contact between enzyme and substrate, and scattering of support have been eliminated It has the advantages of high sensitivity and good accuracy. HRP and its conjugates at f mol level can be detected within 1 similar to 2 min. and the relative standard deviation is 3.9%. 2 References
Enzyme, horseradish peroxidase Chemiluminescence Immunoassay Controlled pore glass Silica gel

"Chemiluminescence Analysis With Reversed Flow Injection Analysis: Studies On ABEI-H2O2-Co(II) Chemiluminescence System And Its Application"
Acta Chim. Sin. 1991 Volume 49, Issue 9 Pages 906-911
LI GUANGHAO;YU ZHENAN

Abstract: A new method has been recommended for the determination of trace amounts Co(II) by reversed flow injection analysis. The optimum reaction conditions of ABEI-H202-Co(II) chemiluminescence system were studied by modified simplex method. The mechanism of this chemiluminescence reaction was studied in detail and a possible reaction mechanism was presented. The selectivity of this chemiluminescence reaction was increased by selecting a proper masking agent. On the basis of above research a chemiluminescence method for the determination of trace amounts Co(II) in natural water has been developed. The detection limit of this method is 1.0 x 10^-11 g mL-1. The linear range is from 5 x 10^-11 to 1 x 10^-7 g mL-1. Recovery is 98-102%. The analysis rate is 100 samples per hour.
Cobalt(II) Hydrogen peroxide Environmental Chemiluminescence Catalysis Reverse

"Chemiluminescence Analysis With Inorganic Coupled Reactions. 1. Determination Of Trace Vanadium With Hydrogen Peroxide - Sodium Thiosulfate - Luminol System"
Acta Chim. Sin. 1988 Volume 46, Issue 6 Pages 543-547
Zhang Zhu-Jun* Ma Wang-Bai Wang Ping

Abstract: The sample (50 to 100 ml) is mixed with 5 mL of acetate buffer solution (pH 2.5), and the solution is passed through a column (15 cm x 15 mm) of strongly basic anion-exchange material at a flow rate of 5 mL min-1. After washing the column with 50 mL of water, V is eluted with 20 mL of 0.6 M NaOH. The eluate is mixed with 5 mL of 0.1 mM H2O2 and 5 mL of 10 mM Na2S2O3 and adjusted to pH 3.5 with 4 M HCl. After adding 5 mL of HCl - K H phthalate buffer solution (pH 3.5), the solution is analyzed by using a chemiluminescence analyzer.. The chemiluminescence intensity is rectilinearly related to concentration. for 0.5 to 30 ppb of V; the detection limit is 0.43 ng mL-1. The coefficient of variation is 3.2% when determining 2 ppb of V. The method has been applied in the determination of V in water.
Vanadium Environmental Ion exchange Chemiluminescence