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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Instrumentation

Classification: Manifold component -> Instrumentation

Citations 48

"Development Of An Online Coupling Of Liquid-liquid Extraction, Normal-phase Liquid Chromatography And High-resolution Gas Chromatography Producing An Analytical Marker For The Prediction Of Mutagenicity And Carcinogenicity Of Bitumen And Bitumen Fumes"
J. Chromatogr. A 1999 Volume 849, Issue 2 Pages 483-494
Jan Blomberg, Paul C. de Groot, Henk C. A. Brandt, Jan J. B. van der Does and Peter J. Schoenmakers

Abstract: A fast and fully automated system for the determination of polycyclic aromatic compounds (PACs) is described. The system has been developed to produce an analytical marker, correlating chemical characteristics (including PAC analysis) with mutagenicity and carcinogenicity. The products of interest are bitumen fumes; bitumen and other (heavy or even residual) oil products, regardless of their boiling range. Dimethyl sulfoxide (DMSO) extractables obtained from a flow injection analysis (FIA) system are introduced online in a normal-phase liquid chromatographic (NPLC) system. Here, the PACs are separated from the DMSO and possible co-extracted heavy residual species. The final step incorporates online gas chromatographic analysis of the three-to-six-ring PAC fraction, followed by flame-ionisation detection for quantification. It was demonstrated that data obtained from samples in the distillate lubrication-oil range correlate well with data obtained from the manual DMSO-extraction method standardised by the Institute of Petroleum as IP346.

"Overcoming Oxygen Quenching In Fluorescence Spectrometry With A Highly Efficient In-line Degassing Device Interfaced With A Flow Cell"
Anal. Chim. Acta 2000 Volume 422, Issue 2 Pages 131-137
Jairo J. Pedrotti, Solange Lima, Nina Coichev and Ivano G. R. Gutz

Abstract: To overcome the quenching effect of oxygen in fluorescence spectrometry, an in-line flow degassing device (FDD) was successfully applied to the removal of oxygen from sample solutions. The FDD consisted of a 3 m long coil of capillary silicone rubber tubing, installed in a glass flask maintained under reduced pressure of N-2 (2.400 Pa). To avoid recontamination of the emerging flow with O-2, the connection of the silicone tube with the fluorimetric cell is made with flexible silica capillary tube. Solutions can be injected with a syringe or feed with a pump. Aqueous solution of ruthenium(II) tris-bipyridil chloride, subject to quenching by oxygen, served as a luminescent probe. The performance was checked against independent amperometric measurements of O-2 with a Clark cell, that correlated well with the O-2 obtained from the fluorescence data using the Stern-Volmer relationship. At a flow rate of 1.0 mL min-1, the concentration of O-2 (measured amperometrically) dropped from 8.24 mg L-1 to 15 µg L-1 for a residence time of 34 s in the FDD, rendering the oxygen quenching effect on [Ru(bipy)(3)](2+) undetectable. The FDD compares favorably with direct inert gas purging of the solution in efficiency and speed. Moreover, it is compatible with flow injection analysis. A frequency of 35 determinations per hour was attained at 1 mL min-1, with good repeatability of the peaks (RSD = 0.8%, n = 25 injections of 200 µl of 1 x 10^-4 M [Ru(bipy)(3)](2+)).
Fluorescence

"Preparation Of Reagents For The Determination Of Fumonisin B1 By Flow Injection Immunoanalysis"
Anal. Chim. Acta 2000 Volume 414, Issue 1-2 Pages 51-60
Ja-an A. Ho and Richard A. Durst

Abstract: Methods for the synthesis of fumonisin B1 (FmB1) immunoconjugates and for the preparation of FmB1-tagged liposomes were developed and studied. Keyhole limpet hemocyanin-fumonisin B1 (KLH-FmB1) was synthesized using both the classical glutaraldehyde (GA) protocol and a modified 2-step GA protocol. The immunoconjugate was then used to raise polyclonal antibodies in Rambouilet sheep. The covalent coupling of FmB1 to the outer surface of the liposomes involved the derivatization of the FmB1 with a maleimide group which was allowed to react with a sulfhydryl group on the liposome surface. The maleimide group was introduced into the FmB1 via a hetero-bifunctional reagent sulfosuccinimidyl 4-[N-maleimidomethyl] cyclohexane-1-carboxylate (sulfo-SMCC). The sulfhydryl group was generated by the deacetylation of an acetylthioacetate group that was incorporated into the lipid bilayer after the interaction of dipalmitoyl phosphatidyl ethanolamine (DPPE) with N-succinimidyl-S-acetylthioacetate (SATA). The sheep anti-FmB1 polyclonal antibodies as well as sulforhodamine B (SRB) dye-encapsulating, FmB1-tagged liposomes were used subsequently in the development of a Flow injection Liposome ImmunoAnalysis (FILIA) system for the detection of FmB1 in food.
Fumonisin B1 Food Immunoassay

"Flow Analysis Based On A Pulsed Flow Of Solution: Theory, Instrumentation And Applications"
Talanta 2002 Volume 58, Issue 6 Pages 1029-1042
Paul S. Francis, Simon W. Lewis, Kieran F. Lim, Karin Carlsson and Bo Karlberg

Abstract: The increased demands placed on solution propulsion by programmed flow systems, such as sequential injection analysis, lab-on-value technology, bead injection and multi-commutation, has highlighted the inability of many conventional pumps to generate a smooth, consistent flow. A number of researchers have examined ways to overcome the inadvertent, uncontrolled pulsation caused by the mechanical aciton of peristaltic pumps. In contrast, we have developed instruments that exploit the characteristics of a reproducible pulsed flow of solution. In this paper, we discuss our instrumental approaches and some applications that have benefited from the use of a reproducible pulsed flow rather than the traditional linear flow approach. To place our approach in the context of the continuously developing field of flow analysis, an overview of other programmed flow systems is also presented. (C) 2002 Elsevier Science B.V. All rights reserved.

"Shah Convolution Differentiation Fourier Transform For Rear Analysis In Microchip Capillary Electrophoresis"
J. Chromatogr. A 2001 Volume 924, Issue 1-2 Pages 177-186
Yien C. Kwok and Andreas Manz

Abstract: This paper first reports the application of Shah convolution differentiation Fourier transform for rear analysis. Rear analysis eliminates the need to create a well-defined and reproducible sample plug, thus making the operation simpler. The number of solution reservoirs, for microchip capillary electrophoresis (CE), could be reduced from the usual four to three. Sample bias in CE could be avoided too. The separation channel was first filled with the fluorescent sample solution, and subsequently flushed out with the buffer. The rear of each analyte zone gives rise to its flight of sigmoid-shaped steps in the time-domain. The time-domain detector signal was first differentiated and then Fourier transform was performed. The Fourier transform results were represented in the form of a magnitude plot. It is proposed that this would be as equally applicable to other separation techniques (e.g., chromatography) and detection methods (e.g., absorption). (C) 2001 Elsevier Science BV All rights reserved.

"Chemiluminescence And Bioluminescence Monitoring -A Flow Injection Approach"
Lab. Rob. Autom. 1999 Volume 11, Issue 2 Pages 91-96
A. Nabi, M. Yaqoob, M. Anwar

Abstract: A conventional instrumentation based on batch procedure and a continuous flow analyzer for monitoring chemiluminescence and bioluminescence reactions are described. A possible development for measuring electrogenerated chemiluminescence would be the incorporation of the electrochemical flow cell in conjunction with flow injection analysis. The advantages of continuous flow analyzer for monitoring these reactions and the detector design are also discussed.

"Digital Acquisition Of Signals From Electrochemical Cells By Virtual Instruments"
Rev. Chim. 2000 Volume 51, Issue 12 Pages 983-985
Vaireanu, D.I.

Abstract: A conductometric microcell with platinum electrodes connected to a processing system with injection was used for the acquisition of digital signals in form of voltage, current or frequency from an electrochemical cell. The data acquisition rate was 0.1-100 measurements/s. The advantages of the digital data collection as compared to graphic systems are related to their higher reliability in conductometric determination of solutions as a function of their concentration. The reproducibility of the experimental data is characterized by very good average standard deviation of 0.62%. (SFS)
Conductometry

"Capillary Flow Injection. Performance Under Pressure"
Anal. Chim. Acta 1998 Volume 366, Issue 1-3 Pages 305-311
Dana M. Spence and Stanley R. Crouch*

Abstract: Some of the pressure and mixing limitations of capillary flow injection systems using pressure-induced flow are described. The benefits of low dispersion and small sample and reagent volumes must be weighed against some of the limitations by potential users. The max. pressure output of conventional peristaltic or syringe pumps can limit the flow rates through microbore capillaries or the types of solutions that can be pumped. Likewise, the peak variance in capillary systems can become limited by injection, detection and connector contributions. Mixing can also be inefficient with capillary systems. Potential solutions to these problems with a new generation of flow injection instrumentation are discussed along with the trade-offs involved.

"Principles And Analytical Applications Of Acoustooptic Tunable Filters, An Overview"
Talanta 1997 Volume 45, Issue 2 Pages 237-248
Chieu D. Tran

Abstract: Advantages of acousto-optic tunable filters have been exploited to develop novel analytical instruments which are not feasible otherwise. The instrumentation development and unique features of such AOTF based instruments including the multidimensional fluorimeter, the multiwavelength thermal lens spectrometer, the near-infrared spectrometer based on erbium doped fiber amplifier (EDFA), and detectors for high performance liquid chromatography (HPLC) and flow injection analysis (FIA), will be described. (C) 1997 Elsevier Science B.V. 32 References
Spectrophotometry Fluorescence Spectrometry Spectrophotometry

"Modeling Chemical Response Surfaces With The Kalman Filter"
Anal. Chem. 1988 Volume 60, Issue 9 Pages 905-911
Peter D. Wentzell, A. P. Wade, and S. R. Crouch

Abstract: A method for the ieast-squares modeling of response swlaces based on the Kahnan filter is described. The method is shown to produce resuits that are identical with more traditional methods, such as dngular value decomposition, but uses a recurslve procedure. The new method is applied to three dlfferent chemical systems, including two flow injection analysts systems and a poiamgraphk system, to demonstrate L features. Advantages of the Kahnan fitter approach arWng from its recurslve nature and its shnplklty are dkwrsed, and its relationship to simplex optimization is addressed.
Glucose Isoprenaline Polarography

"Separation Of Trace Metal Complexes For Analysis Of Samples Of High Salt Content By Inductively Coupled Plasma Mass Spectrometry"
Anal. Chem. 1989 Volume 61, Issue 2 Pages 149-153
Michael R. Plantz, James S. Fritz, Fred G. Smith, and R. S. Houk

Abstract: Solutions of trace metals (Au, Bi, Co, Cr, Cu, Fe, Hg, Mo, Nb, Ni, Pt, Tl, U and V) in aqueous media of high salt content were treated with bis(carboxymethyl)dithiocarbamate reagent (prep. described) and injected into the loading solvent (0.05 M formate buffer of pH 3.25) for application to a column of Amberlite XAD-4 resin. The adsorbed complexes were eluted with aqueous 0.1 M NH3 (pH 11) and the eluate was analyzed by ICP-MS on a Sciex Elan model 250 instrument fitted with a continuous-flow ultrasonic nebulizer. Detection limits in salt-rich aqueous solution ranged from 6 ng L-1 for Bi to 80 ng L-1 for Pt. The method has been used to determine Cr, Ni and Pt in urine, and trace metals in seawater.
Chromium Nickel Platinum Sea Urine Mass spectrometry

"Automated Titrations Using A Discontinuous Programmed-flow Analyser"
Anal. Chem. 1989 Volume 61, Issue 18 Pages 2109-2116
Dennis P. Arnold, Russell M. Peachey, John D. Petty, and Denis R. Sweatman

Abstract: The technique of automated discontinuous programmed flow analysis is described and the operating principles and design of a working prototype instrument, employing syringe pumps driven by interchangeable cams, is discussed. Different cam profiles allow a number of direct reading or reagent addition methods, as well as both single- and dual-flow titrations. Results are presented for argentometric titrations of Cl-1 in water with anodized Ag micro-electrodes contained in two alternative mixer - sensor assemblies as detectors. Precision is generally better than 1% in the range 60 to 160 mg L-1 for analysis times of 30 s. Cycle times can range form 6 to 90 s with negligible sample carryover. Accuracy for waste water is ± 2 to 3%.
Chloride Environmental Waste Electrode

"Biochemical Sensors The State-of-the-art"
Microchim. Acta 1995 Volume 120, Issue 1-4 Pages 243-255
Miguel de la Guardia

Abstract: The basic components of a (bio)chemical sensor and the main concepts involved in the (bio)chemical sensor methodology are considered in order to depict the state of the art of the development of research in this field, paying special attention to the evolution of the published scientific literature in analytical chemistry. (49 References)
Sensor

"Optimization Of A Polarized Photometric Detector Equipped With A Split-type Flow Cell And Its Analytical Application To Oligo-saccharides"
J. Pharm. Biomed. Anal. 1997 Volume 15, Issue 9-10 Pages 1383-1387
Atsushi Yamamoto*, Toshihiko Wataya, Kazuichi Hayakawa, Akinobu Matsunaga, Masayuki Nishimura and Motoichi Miyazaki

Abstract: A novel, non-modulated polarimeter called a polarized photometric detector (PPD) was previously described by the authors. The PPD enables the measurement of the optical rotation of chiral compounds as a change in absorbance by placing two linear polarizers on either side of a flow cell of a conventional photometric detector. The present study describes the optimization of the conditions of PPD for highly sensitive detection of saccharides. To maximize the light intensity, the light balancing filter and slit were removed from the detector (Shimadzu model SPD-10AV). These modifications resulted in an approximately 15-fold increase in the incident light intensity when the maximum current was applied to the lamp. When this intense light was transmitted through the polarizers, the signal intensity followed the theoretical equation for phase angles up to around 1 rad. If the energy of the transmitted light was less than 700 mV, however, the baseline noise was too great to determine the chiral analyte accurately. Setting the phase angle between two polarizers at 50°C and the detection wavelength at 400 nm provided the most suitable conditions. This detector was applicable for the determinations of oligosaccharides in foodstuffs separated by HPLC using gradient elution.
Oligosaccharides Food Polarimetry Spectrophotometry

"Miniaturized Thermal Biosensors"
Sens. Actuat. B 1993 Volume 16, Issue 1-3 Pages 443-447
Bin Xie and Bengt Danielsson, Fredrik Winquist

Abstract: Miniaturized thermal biosensors based on three different designs have been constructed. Properties relevant to decentralized bioanalysis have been investigated. A short measurement period (30 s per sample) and a broad linear range (0. 5 mM to 100 mM for glucose and penicillin-V), using 1 µL sample volume, have been achieved. [References: 11]
Sensor

"Laser Electrochemical Detection Technique In A Flow System"
Anal. Sci. 1995 Volume 11, Issue 1 Pages 1-8
T. HINOUE, R. HARUI, T. IZUMI, I. WATANABE and H. WATARAI

Abstract: A flow electrolytic cell was described (details given) with a Pt working electrode and a SCE reference electrode. The Pt electrode was illuminated with an intermittent Ar+ laser beam (10 mW at 488 nm) in a flowing solution from the front side of the electrode. The current induced (i) by the illumination was recorded as a function of electrode potential (E) with a lock-in amplifier and was directly observed with an oscilloscope. The cell was charged with sample solutions of K4Fe(CN)6 and K3Fe(CN)6 together with 1 M KCl and 5 mM KCN as supporting electrodes. The log plots of the i-E curves were constructed. The current induced by the laser was proportional to the concentration and strongly dependent on the chopping frequency of the laser and the flow rate. The electron transfer was promoted or depressed by the rise in temperature caused by the laser illumination. The effects of instrumental parameters on the laser detection in the flow system was investigated.
Ferricyanide Ferrocyanide Electrode Spectroelectrochemistry

"Recent Advances In Detection In Flow Injection Systems"
Anal. Proc. 1989 Volume 26, Issue 9 Pages 313-315
M. Valcárcel, M.D. Luque de Castro

Abstract: Various approaches to detection in flow injection analysis and their advantages are described including: repetitive passage of the reaction plug through the detector; placement of the detector in the injection valve, which allows continuous monitoring of extraction processes from their early stages; the use of fast detectors capable of rapidly providing various types of data (e.g., absorbance, fluorescence, current intensity) at different instrumental parameters (e.g., wavelength, applied potential) for three-dimentional information, and the use of integrated reaction - detection systems in which one of the components of the reaction is immobilized on a support located within the system.
Sample preparation

"Novel Instrumentation And Biomedical Applications Of Very Near-infrared Fluorescence"
Anal. Proc. 1993 Volume 30, Issue 3 Pages 157-159
M. B. Brown, J. N. Miller, D. P. Riley, N. J. Seare

Abstract: A simple fluorimeter incorporating a light-emitting diode (max. emission at 565 nm) as source and a Si photodiode detector, and accommodating a standard 1-cm cell, was constructed for recording very near-IR fluorescence. The instrument was used in protein-binding studies of Nile red, carried out in aqueous 0.1 M 2-morpholinoethanesulfonic acid buffer (pH 6.9) containing 1 mM MgCl2 and 1 mM EGTA. The effects of bovine albumin, α1-acid-glycoprotein, β-lactoglobulin and ovomucoid on the fluorescence characteristics of the dye are reported and discussed. Fluorimetry of Nile red in acetonitrile afforded a detection limit of 1 µM under both static- and flow injection conditions.
Fluorescence

"Detection Method Based On A Surface Plasmon Resonance And Its Application To Flow Injection Analysis And Liquid Chromatography"
Bull. Chem. Soc. Jpn. 1996 Volume 69, Issue 7 Pages 1969-1974
Xing-Zheng Wu*, Masamitsu Nakagawa, Chiaki Nagamori, Katsumi Uchiyama, and Toshiyuki Hobo

Abstract: The surface plasmon resonance (SPR) detector described consists essentially of a hemicylindrical prism (1 cm diameter x 2 cm) having its flat face coated with a 50 nm film of Ag, and a 3.5 µL flow cell formed by a slit (7 mm x 1 mm) in a piece of 0.5 mm thick PTFE sheet held against the silvered face by a brass holder (diagram given) mounted on a rotating stage so that the angle of incidence could be varied. The generation of SPR in water in the flow cell is demonstrated. SPR detection based on change in the coupling angle and in the reflectivity at a fixed angle were investigated both experimentally and theoretically, and the latter mode is shown by simulation and experiment to be much the more sensitive for the system described. A calibration graph (illustrated) of the reflectivity change vs. propan-2-ol concentration in 20 µL aqueous samples injected into a stream of water in a flow injection system was roughly linear for 0.1-1% of propan-2-ol. Also, a chromatogram obtained by monitoring the reflectivity change is shown for ethanol and propan-2-ol separated on an ODS column.
Ethanol 2-Propanol HPLC

"Automated Fluoriimmunoassay Of Theophylline And Valproic Acid By Flow Injection Analysis With Use Of HPLC Instruments"
Clin. Chem. 1989 Volume 35, Issue 3 Pages 469-470
P Allain, A Turcant and A Premel-Cabic

Abstract: The equipment comprised an HPLC pump, a robotic unit and a fluorimeter. In the robotic unit (Gilson) the serum was twice diluted, then mixed with the reagents (β-galactosyl umbelliferone - drug conjugate and β-galactosidase-labelled antiserum) and with buffer solution All reagents were as supplied for the Ames therapeutic drug assay (Ames Div., Miles Labs., Elkhart, IN). The mixture was heated at 30°C for 16 min, and then injected into the carrier reagent. Fluorescence was measured at 450 nm (excitation at 405 nm). For theophylline, results correlated well (r = 0.98) with those obtained by HPLC on Spherisorb C6 after extraction. For valproic acid, results correlated well (r = 0.96) with those obtained by GC on a 5% FFAP column, after extraction with CCl4. The automated method required only one eighth of the reagent volume used in the manual method. Within- and between-run coefficient of variation were 4.5 and 6.4%, respectively, for 13.8 mg L-1 of theophylline and 3.7 and 6.6%, respectively, for 55 mg L-1 of valproic acid. Detection limits were 1 mg l-1.
Theophylline Valproic acid Blood Serum Immunoassay Fluorescence Clinical analysis

"Microcomputer-controlled Flow Injection Analyzer"
Fenxi Yiqi 1998 Volume 1998, Issue 4 Pages 19-22
Dong Cunzhi; Zi Yanqin; Chen Liguo; Li Yao

Abstract: A flow injection analysis system was designed. The construction and software were described. The analyzer is controlled by a microcomputer through a special-purpose interface. The functions of the software include pump and valve control, data collection and processing, graphic display, and results printing and output. A library of Chinese characters is provided to display menus and other information in Chinese. The test results showed that the performance of the instrument is fairly excellent.

"Automated Immunochemical Analysis Of Specific S-triazine And Phenylurea Herbicides In Drinking Water Supplies"
Food Technol. Biotechnol. 1998 Volume 36, Issue 2 Pages 111-118
Petra M. Krämer

Abstract: Automated immunochemical analysis offers an inexpensive online monitoring or off-line screening of different drinking water sources without extensive sample preparation and without using organic solvents. Two prototype system instruments, one online the other off-line, were studied within the European project, Program Life. Results discussed were performed with the off-line device, where standards and samples are supplied in sep. vials. Automated anal. depends on an extended time of operation without attendants; therefore, all reagents, especially immunoreagents (antibody and enzyme-tracer), should have a stability of at least 14 days. Different stabilization methods were studied. Best stability (at least 14 days) was achieved by adding 0.5% BSA (bovine serum albumin) and 0.5% micro-O-protect, together with storage at 4°C. To reduce buffer salts, which would be discharged to the environment during continuous FIIAA (flow injection immunoaffinity anal.), a comparison of 40 and 4 mM PBS (phosphate buffered saline) as carrier buffer was made. Results showed there was no difference in performance between the 2 carrier buffers. As an example, the system was applied to determine diuron in actual water samples which contained high concentrations of humic substances (9.5 mg/L DOC [dissolved organic carbon]). Samples were collected from groundwater and different water treatment stages of the water supply station in Fuhrberg, Germany, and afterwards spiked with diuron. As a reference method, samples were analyzed by conventional micro-titer plate ELISA, using the same immunoreagents. Determined amounts were generally in good agreement with spiked amts.; FIIAA produced better results.
Herbicides, phenylurea Herbicides, triazine Water Immunoaffinity

"Advances In Flow Analysis Instrumentation"
Int. Lab. 1991 Volume 34, Issue 36 Pages 42-43
Berman, R.F.;Renn, C.N.;Arment, S.F.

Abstract: Details of a new chemical analyzer., the Flow Solution (ALPKEM Corp.), are given. The system uses analytical techniques such as µsegmented-flow analysis (SFA) and flow injection analysis (FIA) and HPLC and combines them into a single hybrid, high performance automated instrument that can be operated in both SFA and FIA modes. For each application, techniques have been experimentally determined that will result in optimal performance and comply with regulatory agency standards.
HPLC

"Instrumentation For Chemiluminescence And Bioluminescence Assays: A Continuous-flow Analyzer. 2."
J. Chem. Soc. Pak. 1992 Volume 14, Issue 4 Pages 281-285
Nabi, A.

Abstract: A purpose-built continuous-flow analyzer for chemiluminescent and bioluminescent detection is described. The advantages of using continuous-flow systems for monitoring these reactions and the detector design are also discussed e.g., good reproducibility due to controlled mixing of sample and reagent, flexible manifold design, high sample throughput, low sample and reagent consumption and
Chemiluminescence Bioluminescence

"Enhancement Of Flow Injection Analysis Based On Liquid-liquid Extraction"
J. Flow Injection Anal. 1993 Volume 10, Issue 1 Pages 2-16
Tadao Sakai and Nohiko Ohno

Abstract: Recent advances in FIA involving liquid-liquid extraction are reviewed. New techniques and instrumentation are covered and applications, with experimental results, are given. (36 references). Since the liquid-liquid extraction based on the flow injection analysis have been dependently introduced by Karlberg et al. and Bergamin et al., techniques and devices on extraction/FIA were developed remarkably for practical usage and also the function was enhanced. This paper describes a practical FIA system with solvent extraction involving new techniques and devices.
Sample preparation

"Portable Battery-powered Flow Injection Analyser"
J. Flow Injection Anal. 1996 Volume 13, Issue 2 Pages 169-170
Teshima, N.

Abstract: An overview is presented of the development of the cited analyzer. equipped with a Ni-Cd rechargeable battery. An example is given of a portable flow injection analyzer. for volatile ethanol using semiconductor gas sensors. (6 references).
Ethanol Sensor

"Instrumentation Based On Microcomputers. 5. A Computer-operated Flow Injection Analyser"
Lab. Microcomput. 1989 Volume 8, Issue 2 Pages 44-52
Malcolme Lawes, D.J.;Pasquini, C.;Wong, K.H.

Abstract: Improvements in the instrument described previously (Anal. Abstr., 1988, 50, 9J17) and its control system are described. The apparatus was applied in the determination of NO2-, NO3-, NH4+ and PO43- in drinking water by conventional colorimetric reactions. Respective calibration graphs were rectilinear up to 0.1, 50, 0.12 and 20 ppm with limits of detection of 4, 30, 5 and 21 ppb. The coefficient of variation (n = 10) were generally 3%.
Nitrite Nitrate Phosphate Ammonium Nitrogen Water Spectrophotometry

"Analytical Methods And Techniques Of Flow Injection Analysis"
Flow Injection Atomic Spectroscopy 1989 Volume 7, Issue 1 Pages 103-156
Fang, Z.L.

Abstract: A review of flow injection atomic spectroscopy that includes: sample introduction techniques, dilution techniques, reagent addition. techniques, calibration methods, indirect methods for atomic absorption spectroscopy, hydride generation methods, cold vapor methods for mercury determination, methods for sequential and simultaneous determinations, and other methods and techniques. 73 references.

"Hardware And Software Of A System For Automatic Control Of Injection Valves Used In FIA And HPLC"
Quim. Anal. 1989 Volume 8, Issue 4 Pages 519-528
Alvarez Ossorio, A.;Rincon, F.;Salva, F.;Cerda, V.

Abstract: A system is proposed for the control of up to four PTFE rotary valves by use of a personal computer. Hardware diagrams and details of the software are presented.
HPLC

"Contemporary Wet-chemical Flow Analyzers For Process Control"
Trends Anal. Chem. 1989 Volume 8, Issue 2 Pages 62-66
M. Gisin and C. Thommen

Abstract: This article gives an outline of an alternative view on the underlying principles of FIA and indicates some directions for the future development of contemporary wet-chemical process analyzers.

"Surface Enhanced Raman Spectroscopy Using Metallic Nanostructures"
Trends Anal. Chem. 1998 Volume 17, Issue 8-9 Pages 557-582
Tuan Vo-Dinh

Abstract: This article provides an overview of the development and application of the surface-enhanced Raman scattering (SERS) techniques using metal-coated nanostructures on solid substrates, An introduction to theoretical principles of the SERS effect and the different SERS-active media is presented. The focus is on nanostructured solid substrates and their practical applications in chemical, environmental and biomedical areas. Specific examples of analytical techniques, instruments and sensors developed in the author's laboratory will be discussed to illustrate the usefulness and potential of the SERS techniques.
Environmental Biological Raman

"Determination Of Copper(II) And Lead(II) In Flow Systems By Stripping Chronopotentiometry"
J. Anal. Chem. 1993 Volume 48, Issue 7 Pages 1151-1157
Myasoedov, B.F.;Krivoshei, E.M.;Kamenev, A.I.

Abstract: The continuous-flow electrochemical cell of the chronopotentiometer comprised a cell (0.1 ml) with an indicator electrode made from graphite fibers (specific surface ~1 m2/g), with a total working end face of 0.25 mm2. A potential of 0.4 V was applied to the electrode. The cell incorporated a Pt wire auxiliary electrode, with Ag/AgCl as reference electrode. The supporting electrolyte was 0.01-0.03 M HCl and the flow rate was ~10 ml/min. Sample (500 µL) was injected into the supporting electrolyte through a nozzle (0.3 mm diameter) 1 mm from the working surface of the indicator electode. A current of 3 µA was passed through the cell. The procedure was suitable for the determination of Pb (0.5-100 µM) in the presence of 10 µM-Cu, and Cu (1-100 µM) in the presence of 10 µM-Pb.
Copper(II) Lead(2+) Potentiometry Electrode

"Automated Sample Preparation Based On The Sequential Injection Principle: Solid-phase Extraction On A Molecularly Imprinted Polymer Coupled On-line To High-performance Liquid Chromatography"
J. Chromatogr. A 2004 Volume 1030, Issue 1-2 Pages 69-76
Georgios Theodoridis, Constantinos K. Zacharis, Paraskevas D. Tzanavaras, Demetrius G. Themelis and Anastasios Economou

Abstract: A molecularly imprinted polymer (MIP) prepared using caffeine, as a template, was validated as a selective sorbent for solid-phase extraction (SPE), within an automated on-line sample preparation method. The polymer produced was packed in a polypropylene cartridge, which was incorporated in a flow system prior to the HPLC analytical instrumentation. The principle of sequential injection was utilised for a rapid automated and efficient SPE procedure on the MIP. Samples, buffers, washing and elution solvents were introduced to the extraction cartridge via a peristaltic pump and a multi-position valve, both controlled by appropriate software developed in-house. The method was optimized in terms of flow rates, extraction time and volume. After extraction, the final eluent from the extraction cartridge was directed to the injection loop and was subsequently analyzed on HPLC. The overall set-up facilitated unattended operation, operation and improved both mixing fluidics and method development flexibility. This system may be readily built in the laboratory and can be further used as an automated platform for on-line sample preparation.

"Fabrication Of A Hybrid Plastic-silicon Microfluidic Device For High-throughput Genotyping"
Proc. SPIE 2003 Volume 4982, Issue 1 Pages 208-219
Isabelle Chartier, J. Sudor, Yves Fouillet, N. Sarrut, C. Bory, A. Gruss

Abstract: The lab-on-a-chip approach has been increasingly present in biological research over the last ten years, high-throughput analyzes being one of the promising utilization. The work presented here has consisted in developing an automated genotyping system based on a continuous flow analysis which integrates all the steps of the genotyping process (PCR, purification and sequencing). The genotyping device consists of a disposable hybrid silicon-plastic microfluidic chip, equipped with a permanent external, heating/cooling system, syringe-pumps based injection systems and on-line fluorescence detection. High throughput is obtained by performing the reaction in a continuous flow (1 reaction every 6 min per channel) and in parallel (48 channels). We are presenting here the technical solutions developed to fabricate the hybrid silicon-plastic microfluidic device. It includes a polycarbonate substrate having 48 parallel grooves sealed by film lamination techniques to create the channels. Two different solutions for the sealing of the channels are compared in relation to their biocompatibility, fluidic behavior and fabrication process yield. Surface roughness of the surface of the channels is the key point of this step. Silicon fluidic chips are used for thermo-cycled reactions. A specific bonding technique has been developed to bond silicon chips onto the plastic part which ensures alignment and hermetic fluidic connection. Surface coatings are studied to enhance the PCR biocompatibility and fluidic behavior of the two-phase liquid flow. We then demonstrate continuous operation over more than 20 hours of the component and validate PCR protocol on microliter samples in a continuous flow reaction. 15 references.

"Characterization Of A Flow-through Microcalorimeter For Measuring The Heat Production Of Cardiac Trabeculae"
Rev. Sci. Instrum. 2005 Volume 76, Issue 10 Pages 4902-4908
A. J. Taberner, I. W. Hunter, R. S. Kirton, P. M. F. Nielsen, and D. S. Loiselle

Abstract: The energy consumption of isolated cardiac trabeculae can be inferred from measurements of their heat production. Once excised from the heart, to remain viable, trabeculae require continuous superfusion with an oxygen- and nutrient-rich solution. Flow-through calorimeters enable trabeculae to be maintained in a stable and controlled environment for many hours at a time. In this paper we describe and characterize a flow-through microcalorimeter, with sensitivity in the 1 µW range, for measuring the heat output of 10 µg cardiac trabeculae. The device uses infrared-sensitive, thin-film thermopile sensors to provide a noncontact method for measuring temperature differences. The sensors are capable of resolving 5 µK temperature differences within the superfusing fluid. The microcalorimeter has a sensitivity of 2.56 V/W at a flow rate of 1 µL/s, with a time constant of approximately 3.5 s. The sensitivity and time constant are strongly dependent upon the flow rate. Predictions of a finite-element model of the calorimeter's characteristics compare favorably with measured data over a wide range of flow rates. ©2005 American Institute of Physics
Calorimetry

"Integrated Microfluidic Systems For Cell Lysis, Mixing/pumping And DNA Amplification"
J. Micromech. Microeng. 2005 Volume 15, Issue 6 Pages 1215-1223
Chia-Yen Lee, Gwo-Bin Lee, Jr-Lung Lin, Fu-Chun Huang and Chia-Sheng Liao

Abstract: The present paper reports a fully automated microfluidic system for the DNA amplification process by integrating an electroosmotic pump, an active micromixer and an on-chip temperature control system. In this DNA amplification process, the cell lysis is initially performed in a µcell lysis reactor. Extracted DNA samples, primers and reagents are then driven electroosmotically into a mixing region where they are mixed by the active micromixer. The homogeneous mixture is then thermally cycled in a micro-PCR (polymerase chain reaction) chamber to perform DNA amplification. Experimental results show that the proposed device can successfully automate the sample pretreatment operation for DNA amplification, thereby delivering significant time and effort savings. The new microfluidic system, which facilitates cell lysis, sample driving/mixing and DNA amplification, could provide a significant contribution to ongoing efforts to miniaturize bio-analysis systems by utilizing a simple fabrication process and cheap materials.

"Micromachine-based Multi-channel Flow Cytometers For Cell/particle Counting And Sorting"
J. Micromech. Microeng. 2005 Volume 15, Issue 3 Pages 447-454
Gwo-Bin Lee, Che-Hsin Lin and Shen-Chie Chang

Abstract: This paper reports a new micromachine-based flow cytometer capable of parallel processing of cell/particle counting and sorting using microfluidic technologies. Hydrodynamic focusing of multiple sample streams is first achieved by using a new layout of sheath flow channels coming from one single inlet port. Thus only one syringe pump is required during the operation. The flow rate of each sheath flow could be much more stable and uniform with this approach. The images of the focused multiple samples are then recorded downstream utilizing a high-speed digital CCD camera. The digital image processing technique is then used to count the number of the cells/particles. Theoretical models based on a 'flow-rate-ratio' method are used to predict the width of the multiple focused streams, which could be incorporated with a digital image processing system for cell/particle counting. Experimental data are found to be highly consistent with the theoretical results. Experimental data show that the developed device can successfully detect the number of cells/particles in two parallel sample streams and the velocities of the cells/particles in each cell line as well. Low counting error and high counting reliability are also verified by counting a mixture of polystyrene beads with different sizes. In addition, human red blood cells are used for the cell-counting test. Subsequently, cell/particle sorting could be achieved using dielectrophoretic (DEP) forces generated by built-in micro-electrodes downstream. Cell/particle sorting has been performed successfully using the DEP electrodes. The development of the multi-channel micro-flow cytometer could be crucial for the advancement of the cell-counting device.
Cells

"Characterization Method For A New Diffusion Mixer Applicable In Micro Flow Injection Analysis Systems"
J. Micromech. Microeng. 1999 Volume 9, Issue 2 Pages 199-202
T Veenstra, T S J Lammerink, M C Elwenspoek and A van den Berg

Abstract: A new mixer is designed for mixing a phenolic solution into water. The mixer design is such that it can be easily adjusted for the controlled mixing of a specific compound within a certain time. This paper describes the working principle of the mixer as well as a suitable characterization method for the mixer. Measurement results are presented which show the correct working of the mixer. A quantitative measure is introduced to express the extent of mixing performed by the mixer. The characterization method allows the measurement of the flow rate, pressure drop and extent of mixing.

"A Review Of Micropumps"
J. Micromech. Microeng. 2004 Volume 14, Issue 6 Pages R35-R64
D J Laser and J G Santiago

Abstract: We survey progress over the past 25 years in the development of microscale devices for pumping fluids. We attempt to provide both a reference for micropump researchers and a resource for those outside the field who wish to identify the best micropump for a particular application. Reciprocating displacement micropumps have been the subject of extensive research in both academia and the private sector and have been produced with a wide range of actuators, valve configurations and materials. Aperiodic displacement micropumps based on mechanisms such as localized phase change have been shown to be suitable for specialized applications. Electroosmotic micropumps exhibit favorable scaling and are promising for a variety of applications requiring high flow rates and pressures. Dynamic micropumps based on electrohydrodynamic and magnetohydrodynamic effects have also been developed. Much progress has been made, but with micropumps suitable for important applications still not available, this remains a fertile area for future research.

"Flow Control For Capillary-pumped Microfluidic Systems"
J. Micromech. Microeng. 2004 Volume 14, Issue 11 Pages 1503-1506
T Vestad, D W M Marr and J Oakey

Abstract: Advantages of performing analytical and diagnostic tasks in microfluidic-based systems include small sample volume requirements, rapid transport times and the promise of compact, portable instrumentation. The application of such systems in home and point-of-care situations has been limited, however, because these devices typically require significant associated hardware to initiate and control fluid flow. Capillary-based pumping can address many of these deficiencies by taking advantage of surface tension to pull fluid through devices. The development of practical instrumentation however will rely upon the development of precision control schemes to complement capillary pumping. Here, we introduce a straightforward, robust approach that allows for reconfigurable fluid guidance through otherwise fixed capillary networks. This technique is based on the opening and closing of microfluidic channels cast in a flexible elastomer via automated or even manual mechanical actuation. This straightforward approach can completely and precisely control flows such as samples of complex fluids, including whole blood, at very high resolutions according to real-time user feedback. These results demonstrate the suitability of this technique for portable, microfluidic instruments in laboratory, field or clinical diagnostic applications.

"Solvent Extraction With Electrokinetic Multicommutation Analysis System"
Instrum. Sci. Technol. 2003 Volume 31, Issue 3 Pages 269-282
Long-Quan Li, Li Fang, You-zhao He

Abstract: The feasibility of solvent extraction with an electrokinetic flow analysis (EKFA) system should be investigated further because of its non-aqueous condition. As an example, the pre-concentration and determination of copper, including on-line color reaction, solvent extraction, and spectrometric determination were carried out by an electrokinetic multicommutation analysis system in this work. The proposed system consisted of one electroosmotic pump, four solenoid valves which were controlled by a personal computer, and a spectrometric detector. With the electroosmotic pump, sample and reagent solutions were aspirated into the system's color reaction section in small plugs, alternately, and were reacted sufficiently. Then, a plug of chloroform was inserted into the colored zone. The proposed system carried out solvent extraction by moving the sandwiched zone back and forth along its short extraction coil. After phase separation with a T-shape separator, organic phase was determined in a flow detection cell of the spectrophotometer. The electroosmotic pump is a liquid delivery device with the merits of non-pulsed and stable flow rate, simple pump structure, high driving efficiency, and facile flow control. Ethanol solution, a relatively high permittivity and innocuous solvent, was adopted as the pump carrier. In this paper, carrier additives were investigated further in order to improve the pump stability and efficiency (3.9 mL min-1 mA-1). The detection limit for copper was 0.03 mg L-1 (K=3, n=11) and its recoveries were in the range of 92-96% with a relative standard deviation of 5.2% (n=3). The proposed method can provide a throughput of 20 samples per hour.
Copper Spectrophotometry

"An Atmospheric-pressure Microplasma Jet Source For The Optical Emission Spectroscopic Analysis Of Liquid Sample"
Plasma Sour. Sci. Tech. 2003 Volume 12, Issue 4 Pages S16-S20
Takanori Ichiki, Toru Koidesawa and Yasuhiro Horiike

Abstract: A miniaturized atmospheric-pressure thermal plasma jet source has been developed as a sensitive detector of a portable liquid analysis system that can fulfil various requirements of `on-site' analysis. The plasma source design required for achieving higher power transfer efficiency to the plasma has been studied mainly so that it can be operated with a commercially available compact VHF transmitter. The developed plasma device is a planar-type inductively coupled plasma (ICP) source that consists of a ceramic chip with engraved discharge tube and a planar metallic antenna with serpentine structures. Effects of chip materials and antenna designs on plasma characteristics are discussed based on the result of optical diagnostics of fine argon plasma jets produced with various prototype sources. Since the load impedance of the plasma jet is so small, it is necessary to contrive ways to lower the antenna impedance to attain higher power transfer efficiency. An atmospheric-pressure thermal plasma jet with a density of approximately 1 x 1015 mL-1 was successfully produced using a compact VHF transmitter at the 144 MHz VHF power of 50 W. The electronic excitation temperature of Ar was found to be 4000-4500 K. Moreover, the method of injection of the liquid sample into microplasma jets has also been investigated and preliminary results of the application to the analysis of tiny amounts of aqueous solution have been demonstrated.
Spectrophotometry

"Amperometric Sensor For Glutathione Based On A Mechanically Immobilized Cobalt Hexacyanoferrate Modified Electrode"
Bull. Chem. Soc. Jpn. 2002 Volume 75, Issue 3 Pages 501-505
Dhesingh Ravi Shankaran and Sangilimuthu Sriman Narayanan

Abstract: A mechanically immobilized cobalt hexacyanoferrate modified electrode has been constructed. The modified electrode exhibits two reversible redox peaks in a 0.1 M NaCl medium, and can be used for the amperometric determination of glutathione. The modified electrode facilitates the catalytic oxidation of glutathione at a reduced overpotential compared with an unmodified graphite electrode. Glutathione was determined in the range of 4 x 10^-5 to 5.2 x 10^-4 M in 0.1 M NaCl and in 0.1 M KCl with correlation coefficients of 0.9991 and 0.9992, respectively. Relative standard deviations of 2.88% in NaCl and 3.27% in KCl were obtained for 4 x 10^-4 M GSH (n = 10). The sensor exhibited excellent stability, reproducibility and immediate response, and can be used in flow-injection analysis.
Glutathione Electrode

"Flow-Type Chemiluminescence Detection Cell Using An Optical Fiber For Capillary Electrophoresis"
Bull. Chem. Soc. Jpn. 1999 Volume 72, Issue 12 Pages 2673-2679
Masahiko Hashimoto, Takeshi Nakamura, Kazuhiko Tsukagoshi, Riichiro Nakajima and Kazuo Kondo

Abstract: A flow-type chemiluminescence detection cell using optical fiber was designed for capillary electrophoresis. The capillary was set up straight to the optical fiber with a certain distance in a Teflon® tube. Hydrogen peroxide was delivered through a three-way joint by a syringe pump and mixed with analytes at the capillary outlet. Luminol chemiluminescence was adapted for use with this detection cell. Analytical conditions, such as hydrogen peroxide flow rate, distance between the capillary and the fiber, and the reagent concentrations, were examined in detail with the cell. The present flow-type system provided a CL signal with high sensitivity, resolution, and reproducibility. The detection limit (S/N = 3) for luminol was 7.6 x 10^-9 M (28 amol; 3.7 nl injected) with theoretical plate numbers of 130000-160000 and a relative standard deviation of 3.3% for the peak height (n = 10). A mixture sample of glycine, glycylglycine, and glycylglycylglycine, which were labeled with isoluminol isothiocyanate (2,3-dihydro-6-isothiocyanato-1,4-phthalazinedione), was also subjected to the present system. They were sensitively detected and represented with high resolution.
Luminol Chemiluminescence Electrophoresis

"Miniaturised Expanded-bed Column With Low Dispersion Suitable For Fast Flow-ELISA Analyses"
Biotechnol. Lett. 2000 Volume 22, Issue 3 Pages 245-250
Eva Pålsson, M.P. Nandakumar, Bo Mattiasson and Per-Olof Larsson

Abstract: Flow-ELISA measurements of the monoclonal antibody concentration in cultivation broth containing murine hybriboma cells were carried out using a small expanded-bed column (0.5 x 2.5 cm) charged with protein A. A new specialised pellicular agarose/stainless steel matrix designed for high flow rates with fast mass transport properties was used. Special care was taken to get an efficient flow distribution. The axial dispersion coefficient was very low (2 x 10^-6 m2 s-1 for latex particles at a linear velocity of 10 cm min-1). Breakthrough curves for polyclonal IgG on the protein A-derivatised support (at 2-11 cm min-1) further emphasised its advantageous properties. No significant change in dynamic capacity was found over the entire speed range.
Antibodies Immunoassay

"A Glucose Sensor Made By Chemically Crosslinking Glucose Oxidase Directly On The Surface Of A Carbon Electrode Modified With Pd/Au For Hydrogen Peroxide Electrocatalysis"
Microchim. Acta 1989 Volume 97, Issue 1-2 Pages 9-16
Xiurong Yang, Gillis Johansson and Lo Gorton

Abstract: Glucose oxidase, mutarotase and bovine serum albumin were chemically crosslinked with glutaraldehyde directly on the surface of a carbon rod, covered with a layer of sputtered palladium/gold to produce a catalytic electrode for hydrogen peroxide oxidation. The polymerization resulted in glucose sensors with response factors that were stable for months under different storage conditions. The thin membranes had a fast response so that flow injection peaks with a width at half peak height of 3 s could be recorded accurately. The detection limit was 0.5 µM D-glucose and the response was linear up to 3 mM D-glucose.
Glucose Sensor

"A New Micro-cell For Continuous-flow Pulsed Voltammetric Analysis"
J. Electroanal. Chem. 1976 Volume 71, Issue 2 Pages 235-240
P.W. Alexander and S.H. Qureshi

Abstract: A flow-through microcell with a mercury pool indicator electrode and a Pt-wire auxiliary electrode was used for continuous-flow determination of Rh(III), as [Rh(NH3)5Cl]Cl2 in a pH 9.3 0.1 M NH3 buffer by differential-pulse voltammetry at -1.63 V vs. SCE. The flow-path was 2.0 mm i.d. The peak resolution at a sampling rate of 60/hr was good. The calibration curve had the shape of an adsorption isotherm at 2.0 ppb Rh, typical for catalyzed electrode reactions. The relative standard deviation was 1.1% in the determination of 1.0 ppb Rh. The detection limit was 0.1 ppb rhodium.
Rhodium(III) Voltammetry

"Biochip Fluorescence Detection System With Spatial And Spectral Separation"
Opt. Lasers Eng. 2006 Volume 44, Issue 11 Pages 1198-1208
Hoseong Kim, Jaeho Choi, Kook-Nyung Lee, Yong-Kweon Kim, Eun-mi Kim and Byung-Gee Kim

Abstract: A novel optical arrangement for fluorescence detection that employs spatial separation as well as spectral filter to increase the signal to noise ratio is proposed. Using a prism and two mirrors, the elliptical laser beam of a laser diode, as an excitation light, is homogenized and the transmitted excitation light is separated from the fluorescence not to reach the collecting optics. Uncooled CCD can capture the fluorescence image of up to 40 fluorescently-labeled protein patterns without scanning or mechanical translation. This paper presents the simulation, construction and measurement results of the developed optical system. The measurements show that the combination of prism and mirrors converts the excitation light from the laser diode to uniform illumination on the specimen, and provides the separation between excitation and fluorescence light to give high signal to noise ratio. It is also possible to assay various protein concentrations ranging from 1000 to 10 ng/ml reliably. We believe that the proposed fluorescence detection system can be used to build a commercially valuable, low cost, hand-held or miniature fast detection device for point-of-care applications.
Fluorescence