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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Robert Kellner

Abbrev:
Kellner, R.
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Institut für Analytische Chemie, Technische Universität Wien, Getreidemarkt 9/151, A-1060 Wien Austria
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Citations 10

"Flow Injection Analysis With Fourier Transform Infrared Spectrometric Detection - A Potential Tool For The Analysis In Complex Matrices"
Vib. Spectrosc. 1993 Volume 5, Issue 1 Pages 33-42
E. Rosenberg and R. Kellner*

Abstract: The combination of flow-injection analysis (FIA) with FT-IR spectrometry as detector is discussed for the determination of glucose in aqueous samples. Time-domain and frequency-domain signal processing are compared and frequency-domain signal processing is found to give superior qualitative and quantitative information. With frequency-domain signal processing, the enzymatic degradation of glucose can be used for its measurement. This method is shown to be successfully applicable in the physiologically interesting concentration range (50-500 mg dL-1). For the quantitative measurement, the difference signal of the sample before and after the reaction is evaluated. Although this approach should theoretically render the method insensitive towards other sample constituents, even with glucose-fructose mixtures severe interferences exist. A possible explanation is the influence on the background spectrum by the pH shift occurring during the reaction.
Spectrophotometry Review

"Determination Of Sucrose By Flow Injection Analysis With Fourier Transform Infrared Detection"
Microchim. Acta 1995 Volume 119, Issue 1-2 Pages 73-79
Bernhard Lendl and Robert Kellner

Abstract: The cited analysis was based on the invertase-catalyzed cleavage of sucrose (I) to α-D-glucose and β-D-fructose in a reactor (3 cm x 3 mm i.d.) packed with invertase immobilized on aminopropylated controlled pore glass using glutaraldehyde (details given). A manifold (diagram given) incorporating two internally-coupled injection valves enabled FTIR spectra of the unreacted and reacted sample to be obtained. Sample (75 µL) was injected into 0.2 M acetate buffer of pH 4.2 (2.1 ml/min) and FTIR spectra were recorded continuously at 8 cm-1 resolution with use of Brucker OPUS GC-IR software and the difference spectrum of the unreacted and reacted sample was obtained. The difference in absorption at 998 and 1038 cm-1 was used to determine I. The calibration graph was linear for 10^-100 mM I. No detection limit or RSD is given. Sample throughput was 45/h. The method was applied to soft drinks.
Sucrose Soft drink Spectrophotometry Immobilized enzyme Controlled pore glass

"Measuring Glucose And Urea By Flow Injection Analysis With FTIR Detection"
J. Mol. Struct. 1993 Volume 294, Issue 3 Pages 9-12
E. Rosenberg and R. Kellner

Abstract: Flow injection analysis with FTIR detection in combination with enzyme catalyzed reactions is used for the determination of glucose and urea in aqueous solution. Due to the specific enzymatic reactions and the spectroscopic detection, the simultaneous determination of both analytes is possible.
Glucose Urea Spectrophotometry

"A Rapid Automated Method For Wine Analysis Based Upon Sequential Injection (SI)-FTIR Spectrometry"
Fresenius J. Anal. Chem. 1998 Volume 362, Issue 1 Pages 130-136
R. Schindler, R. Vonach, B. Lendl, R. Kellner

Abstract: A new process control methodology for the simultaneous determination of sugars, alcohols, and organic acids in wine based on multivariate evaluation of mid-IR transmission spectra of wine samples is presented. In addition to EtOH several lower level wine components (glucose, fructose, glycerol, citric- , tartaric-, malic-, lactic-, and acetic acid) were determined To establish a multivariate calibration model a set of 72 calibration solutions was prepared and measured, using a novel, fully automated sequential injection (SI) system with Fourier transform IR (FTIR) detection. The resulting spectra were evaluated using a partial least square (PLS) model. The developed PLS model was then applied to the anal. of real wine samples containing 79-91 g L-1 EtOH, 5.9-8.1 g L-1 glycerol, 0.4-6.9 g L-1 glucose, 1.5-7.5 g L-1 fructose, 0.3-1.6 g L-1 citric acid, 1.0-1.7 g L-1 tartaric acid, 0.02-3.2 g L-1 malic acid, 0.4-2.8 g L-1 lactic acid, and 0.15-0.60 g L-1 acetic acid, yielding results which were in good agreement with those obtained by an external reference method (HPLC-IR). The short analysis time (<3 min) together with high reproducibility makes the newly developed method applicable to process control and screening purposes (av. of the standard deviations calculated from four repetitive measurements of 6 different real samples: EtOH: 0.55 g L-1, glycerol: 0.037 g L-1, glucose: 0.056 g L-1, fructose: 0.036 g L-1, citric acid: 0.020 g L-1, tartaric acid: 0.010 g L-1, malic acid: 0.052 g L-1, lactic acid: 0.012 g L-1, and acetic acid: 0.026 g L-1).
Sugars Alcohol Acids, organic Ethanol Glucose Glycerol Fructose Citric acid Tartaric acid l-Malic acid Lactic acid Acetic acid Wine Spectrophotometry Sequential injection Method comparison Simultaneous analysis Multivariate calibration Partial least squares

"Determination Of Alkaline Phosphatase Activity In Human Sera By Mid-FTIR Spectroscopy"
Fresenius J. Anal. Chem. 1998 Volume 360, Issue 6 Pages 717-720
B. Lendl A, P. Krieg A, R. Kellner

Abstract: Fourier transform infrared spectroscopy is applied to the determination of alkaline phosphatase (ALP) activity in human sera. 4-nitrophenylphosphate was found to be an excellent ALP substrate for FT-IR spectroscopic detection. The developed method is based on the acquisition of two FT-IR spectra: one recorded immediately after mixing the sample and assay solution and the other after an incubation time of 10 min. Spectral changes in the mid IR range due to the enzymatic reaction could be correlated to the ALP activity in the sample. Experimental conditions were established such that the clinically relevant range for determination of ALP activity in human sera (50 to 900 U/L) was covered. The method was applied to the analysis of ALP activities in standard solutions as well as in human sera yielding results which agreed well with those obtained by a standard reference method.
Enzyme, alkaline phosphatase Serum Human Spectrophotometry

"Flow Injection Analysis With Fourier Transform Infrared Detection For Clinical And Process Analysis"
Fresenius J. Anal. Chem. 1994 Volume 348, Issue 8-9 Pages 530-532
E. Rosenberg and R. Kellner

Abstract: Using glucose and urea as model compounds, 500 µL aqueous solution were pumped (1.1 mL/min) to an FTIR spectrometer fitted with 25 µm pathlength CaF2 windows and background spectra were obtained. A second injection was pumped to an enzyme reactor containing either native or glass-bead immobilized (cf. 'Methods in Enzymology', Vol. 44, Academic Press, NY), glucose oxidase from Aspergillus niger and urease from Canavalia ensiformis. After 10 min, the reaction mixture was pumped to the spectrometer and a second spectrum obtained. The difference in spectra at 1085 and 1125 cm-1 for glucose and 1366 or 1438 cm-1 for urea were correlated to concentrations. Up to 50 mM glucose was quantitatively converted. Applications of the method to fruit juices and simulated plasma containing 40 g/l of BSA are discussed and correlated with reference methods.
Glucose Urea Blood Plasma Fruit Spectrophotometry Clinical analysis

"Colorimetric Determination Of Free And Total Cholesterol By Flow Injection Analysis With A Fiber Optic Detector"
Enzyme Microb. Technol. 1992 Volume 14, Issue 4 Pages 313-316
A. Krug, A. A. Suleiman, G. G. Guilbault and R. Kellner

Abstract: A flow injection method for the determination of total and free cholesterol is presented. Cholesterol esterase and cholesterol oxidase are immobilized on aminoalkyl glass beads. The beads are packed into a tubular glass reactor. The cholesterol esters traversing through the esterase reactor are cleaved to cholesterol and fatty acids. The oxidase reactor converts cholesterol to cholest-4-en-3-one and hydrogen peroxide is generated. The sample stream is merged with reagent streams consisting of a peroxidase solution and a solution of 2,2'-azinobis-(3- ethylbenzothiazoline-6-sulfonic acid)diammonium salt, and a hydrogen peroxide-dependent color reaction takes place in a short coiled reactor. The signal is monitored by means of fiber-optic instrumentation. Cholesterol concentration. can be related to the absorption of the oxidized dye form at a wavelength of 425 nm. The working range is 0.5-0.8 mmol/L, and the sample throughputs are 60 and 30/h for free and total cholesterol, respectively.
Cholesterol, free Cholesterol, total Sensor Spectrophotometry Immobilized enzyme Glass beads Optical fiber Indirect

"Determination Of Amyloglucosidase Activity Using Flow Injection Analysis With Fourier Transform Infrared Spectrometric Detection"
Analyst 1997 Volume 122, Issue 6 Pages 531-534
R. Schindler, B. Lendl and R. Kellner

Abstract: Samples (250 µL each) and a 55 g/l starch solution in 0.1 M acetate buffer of pH 4.3 were simultaneously injected into two aqueous carrier streams (both at a flow rate of 0.88 ml/min) and merged in a reaction coil (250 cm x 0.5 mm i.d.) maintained at 54°C. When the reaction plug had filled the reaction coil, the flow was stopped for 5 min after which the FTIR spectrum was recorded from 950-1300 cm-1. The amyloglucosidase (I) activity was calculated from the difference in the absorbances at 1078 and 1020 cm-1 compared with a reference spectrum of unreacted starch. The calibration graph was linear from 50-2000 U/l I. The method was applied to fermentation broths: recoveries were 98-102% of added I.
Amyloglucosidase Fermentation broth Spectrophotometry Stopped-flow Heated reaction

"Modulation Of The PH In The Determination Of Phosphate With Flow Injection And Fourier Transform Infrared Detection"
Analyst 1997 Volume 122, Issue 6 Pages 525-530
R. Vonach, B. Lendl and R. Kellner

Abstract: A sample (1.5 ml) was injected into a carrier stream at a flow rate of 1.1 ml/min (carrier not specified) and mixed with a stream of acetate buffer at a flow rate of 0.055 ml/min to adjust the pH to 5. The FTIR spectrum (reference spectrum) was recorded from 900-1300 cm-1. A second portion (1.5 ml) of the sample was then injected into the carrier stream and mixed with 100 µL of either carbonate buffer (method A) or NaOH solution (method B) to adjust the pH to 10 or >13, respectively. The FTIR spectrum (sample spectrum) was again recorded. Phosphate was quantified from the difference between the reference and sample spectra, using the peaks at 1085-1095 and 999-1009 cm-1 for methods A and B, respectively. The calibration graph was linear from 0.1-1 g/l phosphate. The throughput was 60 samples/h. The methods were applied to the analysis of soft drinks (results presented).
Phosphate Soft drink Spectrophotometry pH gradient Buffer

"Hyphenation Of Sequential- And Flow Injection Analysis With FTIR-spectroscopy For Chemical Analysis In Aqueous Solutions"
AIP Conf. Proc. 1998 Volume 430, Issue 1 Pages 403-406
B. Lendl, R. Schindler, and R. Kellner

Abstract: A survey of the principles of sequential (SIA)- and flow injection analysis (FIA) systems with FTIR spectroscopic detection is presented to introduce these hyphenations as powerful techniques for performing chemical anal. in aqueous solution The strength of FIA/SIA-FTIR systems lies in the possibility to perform highly reproducible and automated sample manipulations such as sample clean-up and/or chemical reactions prior to spectrum acquisition. It is shown that the hyphenation of FIA/SIA systems with an FTIR spectrometer enhances the problem solving capabilities of the FTIR spectrometer as also parameters which can not be measured directly (e.g. enzyme activities) can be determined On the other hand application of FTIR spectroscopic detection in FIA or SIA is also of advantage as it allows to shorten conventional anal. procedures (e.g. sucrose or phosphate anal.) or to establish and apply a multivariate calibration model for simultaneous determinations (e.g. glucose, fructose and sucrose anal.). In addition to these examples two recent instrumental developments in miniaturized FIA/SIA-FTIR systems, a µ-Flow through cell based on IR fiber optics and a micromachined SI-enzyme reactor are presented in this paper.
Sucrose Phosphate Glucose Fructose Sucrose Spectrophotometry Interface Sequential injection Multivariate calibration Optical fiber