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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Porous glass beads

Classification: Solid phase -> Porous glass beads

Citations 11

"Enzymatic Determination Of Glucose In A Flow System By Catalytic Oxidation Of The Nicotinamide Coenzyme At A Modified Electrode"
Anal. Chim. Acta 1985 Volume 169, Issue 1 Pages 237-247
Roger Appelqvist, György Marko-Varga, Lo Gorton, Arne Torstensson and Gillis Johansson

Abstract: A graphite electrode was chemically modified for the detection of NADH and NADPH by immersion in Meldola blue (C. I. Basic Blue 6) solution The electrodes were mounted in a flow-through cell in a flow injection manifold. For pure solution of the coenzymes the calibration graph was rectilinear for 1 µM to 10 mM coenzyme with a coefficient of variation of 0.2 to 0.6%. Glucose was determined by injection into the carrier stream [0.1 M phosphate buffer (pH 6) - 1 mM NAD+] and passage through an enzyme reactor containing glucose dehydrogenase immobilized with glutaraldehyde on porous glass (pore size 73 nm; particle size 74 to 120 µm) and electrochemical detection with the modified electrode at 0.0 V vs. silver - AgCl. The calibration graph was rectilinear for 1 mM and the detection limit was 0.25 µM for a 50 µL sample.
Glucose Nicotinamide adenine dinucleotide reduced Nicotinamide adenine dinucleotide phosphate reduced Electrode

"Trace Enrichment Of Aluminum Ions On Immobilized Desferrioxamine"
Anal. Chim. Acta 1992 Volume 256, Issue 1 Pages 75-80
Lennart Ljunggren, Ina Altrell, Lars Risinger and Gillis Johansson*

Abstract: Desferrioxamine immobilized on porous glass was packed into a column (100 µL x 2.0 mm i.d.) and placed in the flow manifold of a flow injection system. Samples containing Al3+ were acidified with 1 mM HNO3, injected into the system and merged with NaOH to effect neutralization prior to entry into the column. The carrier was 0.1 M Na acetate buffer with 5 or 20 mM Ca lactate. The metal ions were eluted with 2 M HNO3 and the eluent was analyzed by flame or graphite-furnace AAS. There was quantitative uptake of the Al3+ at pH 5.5 to 6.0. The column temperature was kept at 50°C to allow for ligand-exchange kinetic effects. In the analysis of continuous ambulatory peritoneal dialysis solution, use of the immobilized desferrioxamine column gave improved Al detection limits, down to sub ng L-1 levels, compared with standard AAS. The column showed good stability over a 2 month period.
Aluminum Spectrophotometry Spectrophotometry

"Quenched Peroxyoxalate Chemiluminescence As A New Detection Principle In Flow Injection Analysis And Liquid Chromatography"
Anal. Chem. 1986 Volume 58, Issue 6 Pages 1245-1248
Piet Van Zoonen, Dik A. Kamminga, Cees Gooijer, Nel H. Velthorst, and Roland W. Frei

Abstract: The chemiluminescence method for H2O2, which involves solid bis-(2,4,6-trichlorophenyl) oxalate(I) packed into a cell together with 3-aminofluoranthene immobilized on porous glass beads (CPG-10), is studied. The H2O2 monitor system is as previously described (Anal. Abstr., 1986, 48, 6H41) and the block diagram of the detector is shown. The mobile phase for both flow injection analysis and HPLC is acetonitrile - 0.05 M Tris buffer, pH 8 (4:1) 1 mM in H2O2. Oxidizable compounds, e.g., anilines, NO2- and SO32-, influence the sensitivity of the I chemiluminescence method for H2O2 but do not affect the rectilinear relationship. The quenched peroxyoxalate chemiluminescence method has potential as a detection method for these compounds.
Hydrogen peroxide Chemiluminescence HPLC

"Flow-type Cyanide Sensor Using An Immobilized Micro-organism"
Electroanalysis 1996 Volume 8, Issue 10 Pages 876-879
Kazunori Ikebukuro, Masahiro Honda, Keijiro Nakanishi, Yoko Nomura, Yuzo Masuda, Kenji Yokoyama, Yoshihiro Yamauchi, Isao Karube *

Abstract: A suspension of Saccharomyces cerevisiae cells in 10 mM Tris buffer of pH 8 was prepared and immobilized onto a porous 0.45 µm cellulose nitrate membrane (experimental details given) and the membrane was attached to an oxygen electrode and covered with a dialysis membrane. The electrode was transferred to a flow injection system (schematic shown), in which a reagent solution containing 150 mg/l glucose at a temperature of 30°C was pumped at 0.5 ml/min. The analyte solution, containing suitable concentrations of cyanide (I), was injected into the carrier solution and the corresponding increase in current was recorded. The calibration was linear up to 15 µM I with a detection limit of 1.5 µM. A 10-fold improvement in sensitivity was achieved by immobilizing the cells onto porous glass beads, which were then packed into a syringe body to form a reactor. The reactor was mounted between two oxygen electrodes in a flow-through system (details given) and the difference in the amperometric response of the two electrodes was recorded. The latter system exhibited better sensitivity and was stable for, at least, 16 days.
Cyanide Sensor

"Analytical Application Of Immobilized Acid Urease For Urea In Flow Streams"
Sens. Actuat. B 1991 Volume 5, Issue 1-4 Pages 241-243
Ikuo Satoh* and Masashi Akahane, Kunio Matsumoto

Abstract: A description is given of a system for the calorimetric flow injection determination of urea (I) which is based on acid urease immobilized on porous glass beads packed into a small polymer column. For determination of I, sample is introduced at 1 mL min-1 via a citrate buffer carrier stream (0.1M; pH 5) and the heat generated by the enzymatic hydrolysis of I is monitored through the enzyme thermistor system. The calibration graph was rectilinear from 0.05 to 2 mM I (1 mL samples). Analysis time was 6 min and the coefficient of variation for 1.0 mM I was 1%. The method may be applied to the determination of I in alcoholic beverages.
Urea Calorimetry Thermistor

"Effects Of Organic Solvents On Semicontinuous Immunochemical Detection Of Coumarin Derivatives"
Sens. Actuat. B 1995 Volume 24, Issue 1-3 Pages 80-84
Walter F. M. Stöcklein, Frieder W. Scheller* and Ram Abuknesha

Abstract: The effects of water-miscible organic solvents on immunochemical analyzes was studied with regard to the stability of immobilized antibodies, binding of hapten and conjugation to immobilized antibodies, and marker enzyme stability and activity. Both batch and FIA systems were used. Sheep antibodies were raised against coumarin derivatives and immobilized on porous beads for use with laccase and peroxidase-labelled haptens for competitive ELISA and flow injection immunoanalysis. Horseradish peroxidase (HRP)-catalyzed luminescence was affected by the solvents (up to 20% v/v) in the order THF > acetonitrile > ethanol > methanol. Laccase activity was reduced 50% by 44% ethanol. The effects of organic solvents on antibodies are reported and examples are given for improving the sensitivity and elution efficiency in flow injection immunoanalysis by using solvent-water mixtures.
Coumarins Immunoassay Luminescence

"Flow Injection Immunometric Assay Of 17α-hydroxyprogesterone Using Fluorescein-labelled Fab Fragment"
Anal. Sci. 1994 Volume 10, Issue 1 Pages 109-111
S. MIYAIRI, A. KANAMARU, K. NAKAJIMA, T. KATO and J. GOTO

Abstract: 7α-Carboxymethylthio-17α-hydroxyprogesterone (I), was prepared from 17α-hydroxyprogesterone (II) and condensed with 1-hydroxybenzotriazole in the presence of 1-(3-dimethylaminopropyl)-3-ethylcarbodi-imide hydrochloride. The activated ester was immobilized on aminoalkyl porous glass beads in dioxan/pyridine (1:1). The IgG fraction of rabbit antiserum raised against a I-BSA conjugate was digested with mercuripapain to give Fab fragments. After condensation with fluorescein isothiocyanate, the labelled material was separated on DEAE-Sephadex A-50, with gradient elution from 0.15-1 M NaCl in 10 mM sodium phosphate buffer of pH 7.3 and then on Sephadex G-25 to give F1-Fab. The glass beads were added to the F1-Fab solution at 37°C until the fluorescence intensity at 522 nm (excitation at 495 nm) was no longer decreased. For the flow injection technique, the reactor consisted of F1-Fab bound with immobilized antigen packed in a stainless-steel column (1 cm x 4.6 mm i.d.) connected to a solvent delivery apparatus and equilibrated with 10 mM phosphate buffer of pH 7.3 at 40°C, with detection at 525 nm (excitation at 480 nm). The calibration graph was linear for 10^-300 ng of II.
17-Hydroxyprogesterone Serum Rabbit Spectrophotometry

"A Chemiluminescence Fiber-optic Biosensor System For The Determination Of Glutamine In Mammalian Cell Cultures"
Biosens. Bioelectron. 1992 Volume 7, Issue 8 Pages 569-574
M. V. Cattaneo, K. B. Male and J. H. T. Luong*

Abstract: A chemiluminescence fiber-optic biosensor system has been developed for determining glutamine in hybridoma cell cultures producing monoclonal antibodies against viral surface antigens. Glutaminase and glutamate oxidase (GLO) were immobilized onto aminopropyl glass beads via glutaraldehyde activation separately and packed in a column. Two separate columns containing immobilized GLO and catalase were placed upstream to eliminate endogenous glutamate. In the presence of ferricyanide, luminol reacted with hydrogen peroxide released from the enzymatic reactions to produce a chemiluminescence (CL) light signal which was detected and quantitated with a fiber-optic system. In combination with flow injection analysis it was possible to process samples virtually identically, thus avoiding difficulties in reproducing the CL signal. There was an excellent linear relationship between the CL response and standard glutamine concentration in the range 10^-6 to 10^-3 M. A complete analysis could be performed in 2 min including sampling and washing. Each immobilized enzyme column was stable for at least 300 repeated analyzes without any loss of activity. When the biosensor system was used for the determination of glutamine in spent mammalian cell cultures, the values obtained compared well with those of high performance liquid chromatography, thus validating the applicability of the CL fiber-optic system.
Glutamine Fermentation broth Chemiluminescence Sensor Biotechnology

"Mercuric Ion Sensor With FIA System Using Immobilized Mercuric Reductase On Porous Glass"
Ceram. Trans. 1993 Volume 31, Issue 1 Pages 361-370
Uo, M.;Numata, M.;Karube, I.;Makishima, A.

Abstract: The mercuric ion sensor was prepared with immobilized mercuric reductase covalently coupled to porous glass. The mercuric reductase was immobilized on an arylamino derivative of porous glass with azo coupling. The mercuric ion sensor system was assembled by a flow injection analysis (FIA) system. With an enzymatic cycling reaction constructed by mercuric reductase and catalase, concentrations of mercuric ion >0.025 µM (5 ppb) were detectable by this mercuric ion sensor with 0.2 mL of sample solution Thus, this mercuric ion sensor is suitable for mercuric detection in low concentrations using small sample volumes without any pre-treatment of the samples.
Mercury(II) Spectrophotometry

"Highly Sensitive Flow Injection Analysis Of Glucose And Uric Acid In Serum Using An Immobilized Enzyme Column And Chemiluminescence"
J. Appl. Biochem. 1984 Volume 6, Issue 4 Pages 251-258
Tabata M, Fukunaga C, Ohyabu M, Murachi T.

Abstract: A method for the flow injection analysis of glucose and uric acid in serum using immobilized enzymes in column form and chemiluminescence detection is described. The method is based on the determination of chemiluminescence formed by the reaction of a luminol-ferricyanide mixture with hydrogen peroxide which is produced by the action of the respective oxidases on glucose and uric acid. Glucose or uric acid in serum were determined with 1 µL of the sample at a speed of 120 samples/h without carryover and at an assay time of approximately 10 s. The immobilized glucose oxidase column measured only 1.0 x 5 mm, and the immobilized uricase column 1.0 x 20 mm. The present method gave perfect linearity of the data up to 4.0 g glucose per liter or 0.10 g uric acid per liter with satisfactory precision, reproducibility, and accurate reaction recoveries. Furthermore, the present method was hardly affected by ascorbic acid, while the peroxidase-linked colorimetric method is usually influenced significantly by ascorbic acid. Both column reactors showed good operational stability for a two-month period, during which time they were repeatedly used for analyzes over 2000 times. The results on glucose and uric acid correlated satisfactorily with those obtained by other well-established methods. Glucose oxidase or urate oxidase was immobilized on alkylaminosilanized porous glass beads and was packed into columns (5 mm x 1 mm and 20 mm x 1 mm, respectively). Glucose or uric acid was determined in the sample by measurement of the H2O2 released by the action of the respective oxidase in the column. The H2O2 was measured by the chemiluminescence formed by its reaction with a luminol - Fe(CN)63- mixture, in a 96 µL flow-through cell. The cell and flow diagram for the system are illustrated. The calibration graphs were rectilinear up to 4.0 g L-1 (glucose) or 0.10 g L-1 (uric acid). The within- and between-day coefficient of variation were 1.5%. Recoveries were 96 to 103%. The columns were stable over a two-month period. Results correlated well with those from the Hitachi 726 colorimetric method. The method was affected only slightly by ascorbic acid.
Glucose Uric acid Blood Serum Chemiluminescence

"Colorimetric Assay For Free Fatty Acids In Butter Using Flow Injection And Immobilized Enzymes"
J. Food Sci. 1991 Volume 56, Issue 5 Pages 1229-1232
Schooner, F.;Simard, R.E.;Pandian, S.

Abstract: Butyrate kinase was extracted from frozen Escherichia coli DH5 pJc7 and purified by sonic oscillation in a buffer solution containing dithiothreitol, followed by centrifugation, hydrophobic interaction chromatography with an octyl-sepharose (4 cm x 2.5 cm) and a phenyl-sepharose (10 cm x 2.5 cm) column in series, dialysis, ultrafiltration, affinity chromatography on Matrex Red A (4 cm x 2.5 cm), chromatography on a phenyl-sepharose column (4.5 cm x 1.5 cm) and ultrafiltration. The enzyme was immobilized on porous glass beads and packed in a glass tube as a biosensor coupled with a flow injection analysis (FIA) system. Butter samples were analyzed by the batch method as described by Rose et al. (Methods in Enzymology, 1955, 1, 591) and by FIA coupled with the biosensor. Optical density was read at 510 nm. Detection limits were 25 ppm for the FIA system and 5 ppm for the batch method.
Fatty acids, free Food LC Spectrophotometry Sensor Sample preparation