University of North Florida
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Stuart Chalk, Ph.D.
Department of Chemistry
University of North Florida
Phone: 1-904-620-1938
Fax: 1-904-620-3535
Email: schalk@unf.edu
Website: @unf

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Yong Sheng Li

Abbrev:
Li, Y.S.
Other Names:
Address:
Department of Applied Chemistry, Northeast China Institute of Electric Power Engineering, No. 169 Changchun Road, Jilin City, Jilin Province 132012, China
Phone:
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Fax:
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Citations 13

"Study On Flow-injection Spectrophotometric Determination Of Ppb Level Silicate In Boiler Water And Feedwater In Thermal Power Plant"
Zhongguo Dianli 2002 Volume 35, Issue 11 Pages 22-26
Li Yongsheng Cao Shengxian

Abstract: Based on the flow injection analysis technology and molybdenum blue reaction principle, the successful development of a rapid and accurate determination of the plant boiler water to the water and trace silicon automatic analysis methods. Experiments on the impact sensitivity various factors such as wavelength, temperature, the pump speed, reaction tube length, acidity, size of the quality of sample volume, reductant and the types of design. The method has good repeatability, speed of analysis for 50 ~ 70 samples / h, measured in the range of 0.5-2.0 mg / L and 5 ~ 100 µg / L two quality volume within The results were very good, and the plant can meet the day-to-day analysis of trace silicon needs. (Google translation)
Silicon Water Sample preparation Optimization

"Continuously Automatic Method For Performance Determination Of Strong Alkaline Anion-exchange Resin Used In Water Treatment At Power Plants"
Zhongguo Dianji Gongcheng Xuebao 2004 Volume 24, Issue 4 Pages 204-208
LI Yong-sheng, DONG Yi-ling, YE Yu-lan

Abstract: Chloride ion reacts with mercuric thiocyanate and iron (II) nitrite in acidic media to form a red complex, and the absorbance corresponding to the complex will be proportional to the concentration of chloride. According to the principle, a automatic analytical method used for determining ppb-level chloride has been established by flow-injection spectrophotometry. Based on this method, a flow-injection spectrophotometric method for the performance determination of strong alkaline anion-exchange resin (SAAER) has been developed. The performance of SAAER (201x7 type) was determined, the effects on the exchange capacity of 201x7 type resin, the concentration, using mount and flow rate of regeneration reagent, the flow rate of sample water, ion-exchange temperature, etc. were investigated dynamically. The optimum conditions being suitable for 201x7 resins were obtained. The method is characterized with small device, shorter test-time, simplicity to operate, and good reproducibility. It is more efficient than the manual method, and it is able to apply for the determination of 201x7 type resin performance.

"An Automatic Method Of Online FIA Cation-exchange Pretreating And Anion-exchange Separating For Simultaneous Determination Of Silica And Phosphate In Biological-materials"
Lab. Rob. Autom. 1997 Volume 9, Issue 2 Pages 55-67
Yong-Sheng Li

Abstract: A flow injection analysis (FIA) new method of a continuous ion-exchange pretreatment and separation is given for the simultaneous determination of silicate and phosphate in biological samples. To remove interfering cations, the sample solution passes through the mini cation-exchange column connected at the inlet and outlet of one of the loading loops of a two-channel valve, and it again passes through another loading loop of the valve for sampling. After the valve is switched to the inject position, the defined sample is injected and passed through the seperation column, and silicate and phosphate ions in the sample zone are separated. At the same time, the mini cation-exchange column is switched to the regeneration position and regenerated by a regenerant. By this manner, the sample pretreatment and determination can be made continuously. The approach is extendable to other anion analyzes in various biological samples without matrix matching. 27 References
Silica Phosphate Biological Ion exchange Voltammetry Electrode Column Interferences

"Two New Parameters: Axial-dispersion Degree And Radial-dispersion Intensity Of Sample Zone Injected In Flow Injection Analysis Systems"
Lab. Rob. Autom. 1996 Volume 8, Issue 6 Pages 351-360
Yong-sheng Li*, Xiu-feng Gao

Abstract: This article presents two new parameters of axial dispersion degree (AD) and intensity of radial dispersion (Jf) for describing sample dispersion in flow-injection analysis systems (FIA) and presents their definition equations. AD and Jf not only can be applied for FIA but also for ion, gas, and liquid chromatographies as well as chemical engineering to evaluate axial and radial dispersions of injected materials. Correlation among AD, Jf, Sv, residence time (t), flow rate (Qc), reactor length (L, and dispersion coefficient (D) has been clarified. Qualitative equations related to AD and Jf have been deduced, and some implications of the equations are discussed. Through computer regression calculations with two sets of experimental data obtained from ZCFIA method by Chinese and Japanese FI analyzers, it was concluded that values of coefficients and exponents in these qualitative equations are not identical for different FIA instruments. These qualitative equations are well suitable for predicting and assessing variation tends and correlations of AD or Jf with Qc, L, t, Sv, and D, as well as for optimizing operation conditions in various flow systems.
Radial dispersion

"Relationships Of Exponents With Coefficients Of Equations On Axial And Radial Dispersions In Flow Injection Analysis"
Lab. Rob. Autom. 1996 Volume 8, Issue 3 Pages 171-179
Yong-sheng Li*, Xiu-feng Gao

Abstract: In published articles of the authors [11,13], there are five major qualitative equations on dispersion of sample zone injected into the flow-injection analysis (FIA) system. The five equations contain five coefficients and 10 exponents. This article gives a detailed description of the correlations between these coefficients and exponents in equations on theory of FIA dispersion by means of mathematical derivations and experimental evident. It has been discovered that if a coefficient and two exponents in either of five qualitative equations can be evaluated, the coefficients and exponents in another four qualitative equations can also be solved. Moreover, the mathematical method has also been established for finding the coefficient and exponents in one of the five equations. In addition, a study has been conducted on how to make these qualitative equations change into the five quantitative equations. This article has reported also two new concepts of axial dispersion degree (AD, AD = Sv,z/Sv = t/t) and intensity of radial dispersion (Jf, Jf = D/AD = SvC0/Sv,zCmax = tC0/tCmax) on the sample plug. AD and Jf can be applied not only for FIA but also for ion, gas, and liquid chromatographies as well as chemical engineering to evaluate axial and radial dispersions of injected materials. Correlations among AD, Jf, t, Qc, Lr, Sv, and D have been clarified, and qualitative equations related to AD and Jf were also deduced.
Radial dispersion

"Research On Axial Dispersion And Other Parameters Of Sample Zone In FIA With Zone Circulating Flow Injection Analysis"
Lab. Rob. Autom. 1996 Volume 8, Issue 2 Pages 111-119
Yong-sheng Li

Abstract: A system for multidetection of a sample zone injected into an enclosed-flow system formed by connecting the two parts of a single-line FIA manifold is described. It consists of a mini-pulse eight-channel peristaltic pump, a three-channel synchronous/asynchronous injection valve and a spectrophotometric detector. Using blue ink as a model sample, the relationships between volumetric flow rate, reactor dimensions, residence time volume, peak width, dispersion coefficient and travel time of the sample zone were investigated. A 3D stereo-model was developed to express these relationships.
Peak width

"Automatic Analytical Methods For Monitoring Water-quality At Power-plants With Reversed Flow Injection Analysis"
Lab. Rob. Autom. 1995 Volume 7, Issue 5 Pages 229-238
Li, Y.S.;Wang, Z.J.

Abstract: The quality of the water at power plants has a direct and substantial impact on safe, efficient, and economical operation of the boilers and turbines; consequently, it is being monitored with online or off-line methods at all power plants throughout the world. However, the analytical methods now being employed are based on the principle of an equilibrium of chemical reactions. As a result, undercertain conditions they either are not suitable for rapidly monitoring use because of the limited speed at which analyzes can be performed, or unacceptable lags can occur before the results of an analysis are known. To overcome the drawbacks and compensate for the deficiencies of the online analyzers now being used, the authors have con ducted an attempt to apply rFIA to online monitoring and analysis of the water at power plants. (28 References)
Water Reverse Process control

"Reversed Flow Injection Analysis And Online Chemical Monitoring In Thermal Power Plants"
J. Flow Injection Anal. 1992 Volume 9, Issue 2 Pages 175-186
Li Yong-sheng and Yoshio Narusawa

Abstract: Online monitoring by reversed FIA is described for chemical monitoring in thermal power plants. Methods described include: the determination of phosphate and silicate in boiler water; the simultaneous determination of P and Si in steam water; the determination of Cu in steam water; the determination of SO42- in power plant water and natural water; and the spectrophotometric FIA determination of the exchange capacity of ion-exchange resins.
Phosphate Silicate Phosphorus Silicon Copper Sulfate Water Environmental Spectrophotometry Reverse Process monitoring

"Simultaneous Determination Of Phosphate And Silicate In Boiler Water From Power-plants With Reversed Flow Injection Spectrophotometry"
Fenxi Shiyanshi 1991 Volume 10, Issue 2 Pages 41-44
Li Yongsheng

Abstract: The cited determination was carried out with use of a dual-circuit flow injection apparatus (diagram given). The reaction for determination of phosphate is carried out in one circuit, that for silicate in the other. The molybdophosphate blue (I) and molybdosilicate blue (II) formed are detected spectrophotometrically, I reaching the detector before II. No interference was observed from Cu(II), Fe(II) or Na; phosphate and silicate did not interfere with determination of the other. Calibration graphs were rectilinear from 2.0 to 24 ppm of phosphate and 0.05 to 6.0 ppm of silicate; coefficient of variation were 1% and recoveries were 96.2 to 103.5%. Sample throughput was ~60 h-1.
Phosphate Silicate Water Spectrophotometry Interferences Reverse

"Determination For Exchange Capacity Of Strongly Basic Anion-exchange Resins Based On Flow Injection Analysis"
Fenxi Huaxue 2004 Volume 32, Issue 6 Pages 787-790
Li, Yongsheng, Dong Yiling

Abstract: An automatic method for the determination of trace chloride has been developed based on flow-injection analysis (FIA). By using this method, a FIA determination approach for strongly basic anion-exchange resin performance has been also developed. This method is characterized with small device, rapid determination, easy operation and good reproducibility. It is approximately 30 times more efficient than the manual method. The optimum conditions obtained by experiments are as follows: the flow rate, dosage, and concentration of the regenerant is 0.5 mL/min, 333 mL/g, and 3.0% (W/V), respectively; flow rate of the sample water 1.5 mL/min; exchanging temperature is 25?C ± 5?C.

"Theoretical Studies Of Flow Injection Analysis And Application For Monitoring Water Quality At Power Plants With A Newly Developed Flow Injection Analyser"
Bunseki Kagaku 1996 Volume 45, Issue 1 Pages 107-108
Li, Y.S.

Abstract: The development is described briefly of the FIA-T1-721 analyzer., which is capable of a pump speed of 7.5-150 (±0.5) rpm and shows RSD of 0.5% and a drift of 0.002 absorbance units per h.
Water Environmental

"Determination Of Anion-Exchange Resin Performance Based On Facile Chloride-Ion Monitoring By FIA-Spectrophotometry With Applications To Water Treatment Operation"
Anal. Sci. 2004 Volume 20, Issue 5 Pages 831-836
Yong-sheng Li And Yi-ling Dong

Abstract: Based on a flow-injection spectrophotometry, an automatic analytical method for determination of ppb-level chloride-ion has been established. By use of this method, a novel FIA method for the determination of SBAER performance has also been developed. In this paper, the effects of concentration, dosage, and flow rate of the regenerant on BEC of SBAER were first investigated dynamically by the FIA method. In addition, the flow rate of the sample water and the temperature of the ion exchange resin were also examined. The optimum conditions were obtained: the volume of the regenerant (sodium hydroxide) was 50 mL (0.15 g resin), and its concentration was 3% (w/v); the volumetric flow rates of the regenerant and the sample water were 0.5 ml/min (4.3 m/h) and 1.5 ml/min (13 m/h), respectively. The exchanging temperature was 25 ± 5°C. The method is characterized by the use of a µresin-column, shorter testing cycle, easy operation, and high reproducibility. The proposed method is approximately 30 times more efficient than the manual method, and it can be used for the exchange performance comparison of various SBAER.

"Simultaneous Determination Of Silicate And Phosphate In Boiler Water At Power Plants Based On Series Flow Cells By Using Flow Injection Spectrophotometry"
Anal. Chim. Acta 2002 Volume 455, Issue 2 Pages 315-325
Yong-Sheng Li, Yu Muo and Hou-Mei Xie

Abstract: A new flow injection spectrophotometric method is described for the simultaneous determination of silicate and phosphate. Effects on the sensitivity of the method of the wavelength, temperature, length of reaction coils, pump rates, acidity, sampling volume, concentration of the chromogenic reagent, etc. were also investigated. The optimum conditions were ascertained.The principle of the method is that total concentration of silicate plus phosphate is determined when a injected sample plug is passing through the first flow cell and then the concentration of silicate is serially) determined at a second flow cell of the same detector after continuously masking the yellow molybdophosphate in the sample zone. Finally, the concentration of phosphate is obtained by difference.Silicate and phosphate are determined in boiler water at power plants; 60-120 samples h-1 be analyzed. Determination ranges are 0.05-22 mg L-1 for silicate and 0.1-24 mg L-1 for phosphate. Relative standard deviations for metasilicate and orthophosphate were <=1.2 and 1.3%, respectively. Recovery ranges of silicate and phosphate in the samples are 98-103%.