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: Industrial -> process liquor

Citations 19

"Analytical Options For Control Of Acids And Bases In Hydrometallurgical Processes"
Process Control Qual. 1999 Volume 11, Issue 4 Pages 289-300
Fernando Albertús, Isel Cortés, L.-G. Danielsson and Folke Ingman

Abstract: The most common procedures for the determination of acids and bases in hydrometallurgical process liquors are reviewed and compared. Automated batch titrations, performed by stepwise addition of titrant and using Gran plots for evaluation are reliable but slow compared to flow techniques. Continuous flow titrations are grouped into three classes: Flow Injection Titration, Single Point Flow Injection Titration, and Triangle-programmed Flow Titrations. Furthermore, Sequential Injection Analysis is also considered for process applications. Each one of these methods has advantages and drawbacks. An overview of the most common application problems, and the way they are solved with each methodology, is given. The analytical characteristics of the described procedures are given as well as a guide for the choice of technique for a given application.
Titrations Sequential injection Review Method comparison

"Determination Of Total And Extractable Hydrogen Peroxide In Organic And Aqueous Solutions Of Uranyl Nitrate"
J. Radioanal. Nucl. Chem. 1999 Volume 240, Issue 1 Pages 5-13
Ph. Goodall

Abstract: The development of a spectrophotometric method for the determination of hydrogen peroxide in uranyl nitrate solutions is reported. The method involves the measurement of the absorbance at 520 nm of a vanadyl peroxide species. This species was formed by the addition of a reagent consisting of vanadium (V) (50 mmol L-1) in dilute sulfuric acid (2 mol L-1 H2SO4) This reagent, after dilution, was also used as an extractant for organic phase samples. The method is simple and robust and tolerant of nitric acid and U(VI). Specificity and accuracy were improved by the application of solid phase extraction techniques to remove entrained organic solvents and Pu(IV). Reverse phase solid phase extraction was used to clean-up aqueous samples or extracts which were contaminated with entrained solvent. A solid phase extraction system based upon an extraction chromatography system was used to remove Pu(IV). Detection limits of 26 µmol L-1 (0.88 µg mL-1) or 7 µmol L-1 (0.24 µg mL-1) for, respectively, a 1 and 4 cm path length cell were obtained. Precisions of RSD = 1.4% and 19.5% were obtained at the extremes of the calibration curve (5 mmol L-1 and 50 µmol L-1 H2O2, 1 cm cell). The introduction of the extraction and clean-up stages had a negligible effect upon the precision of the determination. The stability of an organic phase sample was tested and no loss of analyte could be discerned over a period of at least 5 days. The presence of trace levels of reductants interfered with the determination, e.g., hydrazine (<2 mmol L-1)), but this effect was ameliorated by increasing the concentration of the colorimetric reagent.
Hydrogen peroxide Spectrophotometry Interferences

"The Miniaturisation Of The Standard Method Based On The N,N -diethyl-p-phenylenediamine (DPD) Reagent For The Determination Of Free Or Combined Chlorine"
Water Res. 1999 Volume 33, Issue 2 Pages 375-380
Karin Carlsson, Ludvig Moberg and Bo Karlberg

Abstract: A miniaturised continuous flow method for the determination of free or combined chlorine in purification plant water has been developed. The method is based on the standard batch procedure which uses a phosphate buffer for pH adjustment and N,N-diethyl-p-phenylenediamine (DPD) as a colorimetric reagent. The sample, the reagent and the buffer Solutions are continuously pumped into a miniaturised flow system. The mixing, the thermostating and the chemical reaction take place in a manifold with an engraved zigzag flow channel. A flow through detector is positioned at the flow channel outlet. The flow channel volume is about 25 µl and the detector volume is 0.25 µl. An experimental design was performed revealing that the significant variables were the total flow rate and the length of the mixing channel. Based on the results from this experimental design a total flow rate of 90 µl/min and a channel length of 60 mm were selected. The total consumption of sample and reagent is less than 3.91 per month when the system is operated continuously. The response time is less than 2 min. When combined chlorine, in essence chloramine, is determined, potassium iodide is added to the buffer solution. The limit of detection is 3.2 µM for free chlorine and 1.9 µM for monochloramine.
Chloride Spectrophotometry Process monitoring Miniaturization Microfluidic Optimization

"Investigation Of Aerobic Degradation Kinetics Of Surfactants Using Respirometric Batch Experiments"
Acta Biotechnol. 1999 Volume 19, Issue 4 Pages 293-304
A. Schreiner, C. Asmussen, U. Wiesmann, H.-J. Stan

Abstract: The mineralization of a non-ionic alcohol ethoxylate (AEO) surfactant was investigated over the concentration range occurring in rinsing water from surfactant production processes. For this, an experimental set-up for respirometric batch experiments was developed. The set-up and the method were validated by experiments with glucose as the single carbon source. It was possible to calculate substrate decay from the time course of exogenously consumed oxygen during respirometric batch experiments. The kinetic coefficients calculated by respirometry showed a lower standard deviation than those calculated from measured glucose concentrations. The degradation mechanism of AEO was investigated by identification of metabolites, occurring during the mineralization process of AEO, using Flow Injection Mass spectrometry (FI-MS). It was concluded that the degradation of AEO occurs in two main steps. First, the enzymatic hydrolysis of AEO into alcohol and polyethylene glycol (PEG) is performed. Second, the mineralization of both substances takes place, while the mineralization of the alcohol is faster than that of the PEG. The mineralization kinetics were investigated in respirometric batch experiments. The model used is based on double MONOD kinetics for the substrates being produced by hydrolysis (µ(max1) = 0.047 hr-1, K-S1 = 15 mg/l DOC for alcohol; µ(max2) = 0.027 hr-1, K-S2 = 4 mg/l DOC for PEG). The validation of the model by calculating the results obtained from measurements in a continuously operated lab scale CSTR with bacteria recycle was successful.
Alcohol ethoxylate Mass spectrometry

"Spectrophotometric Determination Of Thiocyanate By Sequential Injection Analysis"
Anal. Chim. Acta 2000 Volume 403, Issue 1-2 Pages 279-286
J. F. van Staden and A. Botha

Abstract: A sequential injection analysis (SIA) system was developed for the spectrophotometric determination of thiocyanate as Fe(SCN)(2+). The physical parameters (flow rate, sample and reagent volumes, holding coil and reaction coil internal diameter and length) which influence dispersion in a SIA system were optimized. The effect of the reagent concentration and nitric acid concentration tin the reagent solution and carrier stream, respectively), were also studied. Reagent consumption was effectively reduced by introducing the reagent as a zone into the nitric acid carrier stream, compared to flow injection analysis where the reagent itself is the carrier stream. The system is fully computerized and able to monitor thiocyanate in samples at 24 samples per hour with a relative standard deviation of <1.20% for samples and standards with thiocyanate concentrations above 10.0 mg L-1. The calibration graph is linear from 2.0 to 150.0 mg L-1 with a 3s detection limit of 1.1 mg L-1. The system has been applied to the determination of thiocyanate in process solutions and waste waters.
Thiocyanate ion Spectrophotometry Sequential injection Process monitoring Optimization Computer

"Flow Injection Spectrophotometric Determination Of Copper Using Bis(cyclohexanone)oxalyldihydrazone"
Anal. Chim. Acta 1995 Volume 304, Issue 1 Pages 97-100
N. Chimpalee, D. Chimpalee, S. Srithawepoon, T. Patjarut and D. Thorburn Burns*

Abstract: A sample (250 µL) was injected into a water carrier stream (1.35 ml/min) which was then sequentially merged with streams (1.35 ml/min) of 27% citric acid solution, 37% ammonia solution and 0.18% bis(cyclohexanone)oxalyldihydrazone solution then passed through a reaction coil (4 m x 0.8 mm i.d.) to a detector cell with detection at 600 nm. The calibration graph was linear up to 20 µg/ml Cu; the detection limit was 1.3 µg/ml and RSD was 0.92% (n = 10). The method was applied to the determination of Cu in steels, copper-based alloys and pig feeds and to copper monitoring in an alkaline scale-removal process.
Copper Spectrophotometry Complexation

"Methods For Online Monitoring To Be Implemented In An Ammonium Thiosulfate Production Plant"
Anal. Chim. Acta 1995 Volume 308, Issue 1-3 Pages 187-196
J. S. Cosanoa, A. Izquierdoa, M. D. Luque De Castroa,*, M. Valc&aacute;rcela, C. Aguilarb and G. Penelasb

Abstract: Automatic online flow injection methods are described for (i) monitoring the major component of the production process, namely 60% ammonium sulfite (I) and ammonium thiosulfate (II) at the reactor inlet and outlet, respectively, and (ii) determination of ~e;0.7% I in the presence of high concentrations of II (~e;60%) at the reactor outlet. The reducing properties of both I and II were utilized for i by monitoring the decoloration of in situ formed iodine at 352 nm. RSD for the determination of 70% I and 50-60% II were 6 and 1%, respectively. For ii the decoloration of p-rosaniline by sulfite in neutral or slightly basic medium was employed. Detection was at 540 nm. A linear calibration graph was obtained for 2.7-20 g/l of I in the presence of 60% II. The RSD (n = 11) for 0.23% I was 2.8% and the sampling frequency was 8 samples/h. Detailed experimental procedures for both methods are given.
Sulfite Thiosulfate ion Spectrophotometry Automation Process control

"Determination Of Codeine In Process Streams Using Flow Injection Analysis With Chemiluminescence Detection"
Anal. Chim. Acta 1996 Volume 318, Issue 3 Pages 309-317
Neil W. Barnett*, Tim A. Bowser, Richard D. Gerardi and Brent Smith

Abstract: A FIA method is described for the determination of codeine in aqueous solutions obtained during full-scale process extraction of alkaloids from Papaveraceae somniferum. The method was based on the chemiluminescence of tris(2,2'-bipyridyl)ruthenium, Ru(bipy)32+. A 20 µL volume of 4 mM Ru(bipy)32+ was injected into a 10 mM acetate carrier stream (10 ml/min) of pH 6 and transported through a solid-phase reactor consisting of lead dioxide immobilized on silica gel to produce Ru(bipy)33+. The flow was then merged with the sample stream (10 ml/min) and propelled to the detector where the chemiluminescence was measured with a photomultiplier tube. The calibration graph was linear for 0.01-1 µM-codeine, the detection limit was 5 nM and the RSD (n = 5) for 0.5 µM-codeine was 1.6%. Process solutions were diluted 105-fold with acetate buffer of pH 6 prior to analysis and a standard additions calibration procedure was used.
Codeine Chemiluminescence Solid phase reagent Silica gel Standard additions calibration

"The Determination Of Vanadium(V) In The Presence Of Vanadium(IV) Using 4-(2-pyridylazo)resorcinol In A Flow Injection Manifold"
Anal. Chim. Acta 1996 Volume 329, Issue 3 Pages 275-284
M. J. C. Taylor, G. D. Marshall, S. J. S. Williams, J. F. van Staden and C. Saling

Abstract: Process streams arising from flue-gas scrubbers, and containing V(V) and V(IV) were filtered (0.2 µm) and 100 µL injected into an aqueous carrier stream of 2 g/l CDTA and the solutions mixed in a 200 µL stirred chamber. After a known time delay, a 50 µL fraction was switched into a carrier stream of 5 mM CDTA/68 pM-4-(2-pyridylazo)resorcinol (PAR) in 100 mM KH2PO4 buffer of pH 5.3, mixed in a reaction coil (2.5 m) and the resultant V(V)-PAR complex detected at 550 nm. Calibration graphs were linear up to 5 mg/1 of V(V) a RSD (n = 10) of 0.03% for 0.1 g/l V(V). Interference from a range of cations including V(IV) was non-significant.
Vanadium(V) Spectrophotometry Interferences Mixing chamber Speciation Buffer

"Flow Injection Pervaporation Coupling For The Determination Of Sulfide In Kraft Liquors"
Fresenius J. Anal. Chem. 1996 Volume 354, Issue 4 Pages 442-446
I. Papaefstathiou, M. D. Luque de Castro and M. Valc&aacute;rcel

Abstract: A sample that contained sulfide ions was injected or aspirated into a stream (1.3 ml/min) of 1 M TCA of pH 1.16 in advance of a coil (30 cm) and the mixture led into a pervaporation module at 60°C, with a PTFE membrane (5 µm pore) permeable to H2S. The latter was trapped in an upper stream (1.3 ml/min) of 1.92 mM p-diethylaminoaniline in 1 M TCA of pH 1.16 mixed with 3.73 mM ferric ammonium sulfate in 0.044% H2SO4 (0.7 ml/min) and the ethylene blue product monitored at 670 nm. Calibration graphs were linear for 1-15 µg/ml sulfide (injection) or 1-10 µg/ml sulfide (continuous aspiration). Detection limits were 0.68 µg/ml (RSD 5.46%) and 0.42 µg/ml (RSD 8.03%), respectively. Determination of 5 µg/ml sulfide was affected by 5 µg/ml Cd(II); Zn(II), Fe(III), sulfite, carbonate and thiosulfate ions interfered only at 50 orders of magnitude. Sulfide determinations in white and green bleaching liquors agreed quite well with a standard methylene blue procedure.
Sulfides Spectrophotometry Interferences Pervaporation Teflon membrane Heated reaction

"Determination Of Morphine In Process Streams By Sequential Injection Analysis With Chemiluminescence Detection"
Fresenius J. Anal. Chem. 1996 Volume 355, Issue 5-6 Pages 591-595
N. W. Barnett Contact Information, Simon W. Lewis and Daryl J. Tucker

Abstract: A manifold is described for the determination of morphine in process streams, based on its chemiluminescent reaction with 2 mM KMnO4 in 1% sodium hexametaphosphate of pH 3. A modular injection system was used in the sequential injection mode. The emission was monitored at 610 nm using a flow-through fiber-optic cell and a sensitive, low dark current photomultiplier tube. The calibration graph was not linear over the entire concentration range from 0.02 µM to 0.1 mM, but approximated linearity from 2.5-30 µM. The estimated detection limit was 25 nM-morphine; RSD was 1.4% (n = 15) at the 12.5 µM level. The structurally related compound codeine did not interfere significantly, but the results suggested that matrix effects could occur depending on the sampling location.
Morphine Chemiluminescence Sequential injection Optical fiber Interferences

"Coulometric Determination Of The Flow Rate Of Small Masses Of Substances. 2. Application To Online Measurement Of The EOX-parameter"
Fresenius J. Anal. Chem. 1997 Volume 357, Issue 6 Pages 582-588
M. Luitjens, H. Kupka, D. Gherban, E. Baumgarten

Abstract: A previously developed coulometric method (Ibid. 1993, 347, 87) has been coupled with a FIA system and applied to the analysis of the EOX-parameter extractable organic halogens (where X = Cl, Br and I). The titration curve was determined using the coulometric system for the determination of the adsorbable organic halogen (AOX) global parameter described in the previous paper (loc. cit.). The curve was then integrated into computer software which evaluated the time dependent signal. The flow rate can then be calculated (details given). For online analysis, water samples were mixed with hexane (1:40) with stirring for 1 h; flow rates were 1.4 and 0.1 ml/min for the aqueous and hexane phases, respectively. The phases were separated and hexane extracts were combusted at 700°C in Ar/O with a Pt/Pd catalyst (system details given). Recoveries were >70%; detection limit was 0.1 mg Cl/l. Applications include waste water and process water control.
Organics, halogenated Coulometry Computer

"Measurement Of Total Alkali And Phenol In Process Liquor By Flow Injection Analysis"
Microchim. Acta 1986 Volume 90, Issue 3-4 Pages 175-186
J. A. Sweileh, P. K. Dasgupta and J. L. Lopez

Abstract: The flow injection manifolds are described (with diagrams). For determination of total alkali, sample solution was injected into the titrant carrier stream containing dodecylbenzenesulfonic acid and conductometric detection was used. Total phenol was determined with use of the Berthelot reaction with NaClO and NH3 to form indophenol blue and measurement at 660 nm.
Phenol Alkalinity, total Conductometry Spectrophotometry Valve

"Spectrophotometric Flow Injection Techniques For The Multi-component Monitoring Of Process Streams"
Microchem. J. 1992 Volume 45, Issue 2 Pages 178-188
Paul MacLaurin and Paul J. Worsfold*

Abstract: An overview of simultaneous determinations in flow injection analysis (FIA) is presented and the advantages of photodiode array detection are discussed. The application of multivariate calibration procedures to nonselective data is outlined and examples of its use in FIA are reviewed. The role of flow injection techniques in process anal. and the potential of FIA-photodiode array-multivariate calibration systems for online multideterminations are also considered. A review with 107 references. An overview is presented, with 107 references. Particular reference is made to photodiode-array detection and the advantages of applying multivariate calibration procedures to the data.
Spectrophotometry Review Multicomponent Multivariate calibration

"Study Of Flow Injection Analysis - Inductively Coupled Plasma Atomic-emission Spectrometry. 4. Rapid Method For The Determination Of Trace Scandium"
Fenxi Huaxue 1990 Volume 18, Issue 12 Pages 1152-1154
Chen, H.;Jiang, Z.C.;Lai, Z.;Liao, Z.H.

Abstract: Trace Sc in technological processing solution is determined by the cited method (details given) in the presence of matrix elements (30 mg mL-1 of Fe and 10 mg mL-1 of Ti). Interference from matrix elements is investigated, and conventional and flow injection analysis sample introduction methods are compared. For the injection of a 0.5 mL portion of sample solution with detection at 363.075 nm, the detection limit was 8.4 ng mL-1 of Sc and coefficient of variation (n = 12) were 2.5%.
Scandium Spectrophotometry Interferences Detection limit Method comparison

"Determination Of Total Ammonia And Carbon Dioxide In Liquors From The Caron Process For Nickel Extraction"
Process Control Qual. 1996 Volume 8, Issue 4 Pages 185-192
F. Albert&uacute;s, I. Cort&eacute;s, L.-G, Danielsson and F. Ingman

Abstract: A 110 µL sample is injected into a carrier stream of water (2.32 ml/min) that then merges with the reagent stream (0.57 ml/min) before passage through a reaction coil (60 cm x 0.5 mm i.d.) and spectrophotometric detection. For the measurement of total alkalinity (NH3 + CO2), the reagent is 0.5 M acetic acid/0.5 M NaNO3/40 µM-bromophenol blue and the absorbance is measured at 592 nm; for the measurement of strong alkalinity (NH3), the reagent is 0.45-0.5 M H3BO3/40 µM-cresol red containing also NaNO3 with measurement at 572 nm. Calibration was effected by non-linear regression. The RSD were 3 and 2.
Ammonia Carbon dioxide Spectrophotometry Sample preparation Extraction Non-linear regression

"Online Analysis Of Caustic Streams By Near Infrared Spectroscopy"
Spectroscopy 1987 Volume 2, Issue 1 Pages 44-48
Watson, E.;Baughman, E.H.

Abstract: The application of near-IR spectrometry in the range 1.5 to 2.4 µm can, with careful choice of analytical and reference wavelengths to obtain the appropriate concentration. range and to avoid interferences by foreign species, be a convenient and useful method for determination of NaOH in, e.g., waste waters and acid-gas scrubbers.
Sodium hydroxide Spectrophotometry Interferences

"Semiautomatic Method For Determination Of Iron(II) And Iron(III) By Using Flow Injection And A Coulometric Monitor"
Sumitomo Tokushu Kinzoku Giho 1984 Volume 7, Issue 1 Pages 33-37
Kikui, Fumiaki; Hayakawa, Tetsuji (SFS)

Abstract: The method involves monitoring Fe3+ by using a coulometric monitor with a C electrode at 0.26 V vs. NHE and an auxiliary electrode with K4Fe(CN)6-K3Fe(CN)6-KNO3-NH4OH electrolyte. The method was used for monitoring FeCl3 etching solutions containing Co, Cr, and Ni. For determining total Fe the divalent ions were 1st oxidized by boiling with H2O2. (SFS)
Iron(2+) Iron(III) Coulometry Simultaneous analysis

"Applications Of Flow Injection Analysis In Textile Processing"
J. Flow Injection Anal. 2000 Volume 17, Issue 1 Pages 11-22
Y. Maeshima, H. Ueta, T. Harikou

Abstract: In the textile industry, the use of enzymes are being advanced as a mild and environmentally friendly process for cotton. Methods for rapid and simple monitoring of enzymatic activities are desirable for dyeing/finishing process control. In this paper, some attempts to determine enzymatic activity such as cellulase, pectinase, glucos eoxidase using flow injection analysis (FIA) are described. Applications of FIA to monitor hydrogen peroxide and peroxysulfate for desizing/scoring/bleaching process, indido dyes and hydrosulfite for pad-airing dyeing process are also described.
Enzyme, activity Enzyme, cellulase Enzyme, pectinase Enzyme, glucose oxidase Spectrophotometry Electrode