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
Website: @unf

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Classification: Water -> boiler feed

Citations 7

"The Analysis Of Aqueous Solutions With Ethanol Soluble Reagents In A Flow Injection System. Spectrophotometric Determination Of Uranium"
Anal. Chim. Acta 1984 Volume 160, Issue 1 Pages 11-19
Catharina Silfwerbrand-Lindh, Lage Nord, Lars-Göran Danielsson and Folke Ingman

Abstract: The aqueous sample solution (acidified to pH ~2), containing traces of U, was injected into a stream of aqueous 2.5% trans-cyclohexane-1,2-diamine-NNN'N'-tetra-acetic acid (adjusted to pH 7 with 5 M NaOH) and aqueous triethanolamine buffer solution (pH 7.85). This stream was mixed with reagent solution [aqueous 96% ethanol containing 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol and the cited buffer] and the absorbance was measured at 578 nm. A tight coil of PTFE tubing (0.5 mm) provided the most effective mixer. A second injection of each sample was required to establish the 'reagent blank' (details given). The calibration graph was rectilinear up to at least 5 mg L-1 of U; the detection limit was 0.15 mg l-1. Sixty samples could be analyzed in 1 h. Iron, Ca, NH4+, SO42- and F- were tolerated, but PO43- (even at moderate levels) and CO32- (at high levels) interfered.
Uranium Spectrophotometry Interferences

"Online Monitoring Of Trace Amounts Of Copper(II) In Steam Condensate And Boiler Feed-water By Flow Injection Analysis Based On Its Catalytic Effect On The Oxidation Of Hydroquinone By Hydrogen Peroxide"
Anal. Chim. Acta 1996 Volume 331, Issue 3 Pages 257-262
Shun-an Cao, Jin-chang Zhong, Kiyoshi Hasebe and Wenzhi Hu*

Abstract: The FIA method for determining trace amounts of Cu(II) was based on the catalytic effect of Cu(II) on the oxidation of hydroquinone by H2O2. A 150 µL sample was injected into a carrier stream formed online by merging 3% H2O2 with phosphate buffer of pH 7.2 (both at 2 ml/min). The resulting mixture was merged with 0.3 M hydroquinone (2 ml/min) and passed through a reactor coil (600 cm x 1 mm i.d.) at 55°C to the spectrophotometric detector where the absorbance at 490 nm was monitored. Calibration was carried out using solutions containing 5-100 µg/l Cu(II). The detection limit was 0.25 µg/l. The RSD (n = 11) for 5-50 µg/l Cu(II) were 0.81-0.86%. The method was applied to monitor Cu(II) in steam condensates and boiler feed water. The recoveries of 5-10 µg/l Cu(II) from spiked boiler feed water and steam condensate were 97-104.4% and 90-116%, respectively.
Copper(II) Spectrophotometry Heated reaction Catalysis

"Low-level Determination Of Hydrazine In Boiler Feed Water With An Unsegmented High-speed Continuous-flow System"
Analyst 1978 Volume 103, Issue 1230 Pages 998-1001
W. D. Basson and J. F. Van Staden

Abstract: The use of hydrazine for the treatment of boiler feed water has been recommended by a number of workers.(1-3) Several methods have been suggested for the determination of hydrazine, all of which depend on its basic character or reducing properties. These methods include oxidation with alkaline permanganate solution,(4) potentiometric titration with iodine chloride(5) and a spectrophotometric method using 2-nitroindane-1,3-dione.(6) Of the possible methods for determining small amounts of hydrazine, the spectrophotometric method of Pesez and Petit(7) appears to be used almost universally because of minimum interference from naturally occurring substances. Watt and Chrisp(8) developed a spectrophotometric method based on the observation by Pesez and Petit that a yellow color developed on addition of 4-dimethylaminobenzaldehyde to solutions of hydrazine in dilute hydrochloric acid solutions. Hydrazine reacts with 4-dirnethylaminobenzaldehyde(7-9) in acidic medium to give a compound with a p-quinone structure that is yellow in solution: Many variants of this method have been published,(9-12) all of which seem to be capable of giving satisfactory results. However, they are all manual methods and the batchwise mode involved is time consuming for laboratories in which a high sample output is necessary or when hydrazine levels are to be monitored continuously. A conventional continuous-flow method with a sampling rate of 60 samples per hour by Technicon13 utilising this method has also been published. The method of unsegmented continuous-flow analysis(14-15) or continuous-flow injection analysis developed by Ruzicka and co-workers(16-17) has been applied successfully in the determination of phosphorus,(14) ammonium(14) and calcium(15) at rates of up to 300 samples per hour. This method utilises the rapid injection of a sample into a continuously moving unsegmented carrier stream of water or reagent solution, forming a slug or zone of sample that is processed and carried into a flow-cell. This paper reports the application of unsegmented high-speed continuous-flow analysis to the low-level determination of hydrazine in boiler feed water.
Hydrazine Spectrophotometry

"Application Of Flow Injection Analysis To Water Quality Measurement And Online Monitoring In Thermal Power Plants"
Bunseki Kagaku 1992 Volume 41, Issue 10 Pages 463-471
Li, Y.S.;Narusawa, Y.

Abstract: Seventeen flow injection manifolds are described for the determination of, inter alia, 0.2 to 80 ppm of phosphate and 0.02 to 5 ppm of silicate in boiler water, 3 to 70 ppb of silicate (with ion-exchange concentration.) in steam water, 0.4 to 100 ppb of Cu2+ in steam water by a catalytic method, and 0.1 to 4 ppm of Fe2+ and 3 to 20 µm of SO42- in power-plant water. A manifold for the measurement of the exchange capacity of an ion-exchange resin is also presented. The operation conditions, advantages and disadvantages of the cited technique are discussed. A dozen FIA methods applicable to power plants, all of which have been developed during the past 8 yr, FIA-T1-721 are described. The methods are: simultaneous determination method of PO43- and SiO32- in boiler water with online FIA (0.2-30 ppm PO43-, 0.02-5.00 ppm SiO32-), FIA concentration. determination of microamounts of silica in water-stream with ion-exchange resin (3.0-70 ppb SiO32-), catalytic FIA spectrophotometric determination of microamounts of Cu2+ in water-stream (0.4-100 ppb Cu2+), FIA spectrophotometric determination of microamounts of Fe2+ in water used in poweer plant (100-4000 ppb Fe2+), rFIA determination of SO42- in water used in power plants (3.0-20 ppm SO42-), and a new method of determining the exchange-capacity of ion-exchange resin based on FIA. The advantages and deficiencies in applying FIA to water quality measurements and online monitoring in power plants are also discussed.
Phosphate Silicate Copper(II) Iron(2+) Sulfate Spectrophotometry Process monitoring Resin

"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 Spectrophotometry Reverse Process monitoring

"Flow Injection Analysis For The Determination Of Trace Amounts Of Silica In Boiler Water"
J. Flow Injection Anal. 1995 Volume 12, Issue 1 Pages 85-90
Tsuboi, T.;Nakamura, T.;Yonezawa, K.;Matsukura, A.;Motomizu, S.

Abstract: Flow-injection method for the determination of trace amounts of silicon, existing as silicate in boiler water was examined spectrophotometrically by using a molybdenum blue coloration reaction. The optimum conditions for the effective formation of molybdenum blue were examined by using a two-line flow system coupled with a sandwich method. The lowest determination range of silicon was 1 µg L (= 1 ppb) of silicon, and a calibration graph was linear over the range from 1 ppb to 100 ppb of silicon. The relative standard deviations for 1 ppb and 20 ppb of silicon were 4.6% and 0.9%, respectively. The method was applied to the determination of silicate in real boiler waters.

"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 Sample preparation Optimization