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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Polarimetry

Classification: Polarimetry

Citations 5

"Evaluation Of A Split-type Flow Cell For A Polarized Spectrophotometric Detector"
Analyst 1995 Volume 120, Issue 4 Pages 1137-1139

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Atsushi Yamamoto, Akinobu Matsunaga, Eiichi Mizukami, Kazuichi Hayakawa, Motoichi Miyazaki, Masayuki Nishimura, Mitsuo Kitaoka and Tomio Fujita

Abstract: A split-type flow cell for a polarized spectrophotometric detector (PPD), in which the column effluent is simultaneously passed through both the sample and reference sides, is described. The improvement in detection sensitivity in PPD with the use of this cell is discussed. Its utility as a universal polarimetric detector for HPLC for the detection of colored amino acid-copper(II) complexes is shown. A new possibility for this cell in the gradient elution separation of glucose syrup is demonstrated.
Detector Flowcell Apparatus

"Flow Injection Analysis With High-sensitivity Optical Rotation Detection"
Anal. Chem. 1994 Volume 66, Issue 19 Pages 3093-3101

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Charles A. Goss, Douglas C. Wilson, and William E. Weiser

Abstract: The construction and characterization of a flow injection analysis system with high-sensitivity, laser-based (488 nm), optical rotation detection (FIA-OR) is described. Baseline noise is reduced to - 10 µdeg by addition of a pressure pulsation damper between the pump and the autosampler. Sensitivity is increased 100-fold compared to a high-quality conventional polarimeter, and detection of a 43 ng sample of sucrose (25-pdeg rotation) is demonstrated. The instrument response is linear over a 500-fold range of concentration to 21 pg of sucrose injected, with the upper limit set by laser beam distortion caused by sample refractive index effects. Specific rotation values at 488 nm for 11 organic molecules are measured by FIA-OR with good precision and agree with values obtained by a conventional polarimeter. FIA-OR analysis of enantiomeric purity of (1S2R)-(+)-ephedrie is found to be more discriminating than conventional polarimetry for the analysis of solutions with high enantiomeric excess.
Apparatus Detector

"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

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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 Instrumentation Flowcell Optimization

"Theoretical Consideration On Polarized Photometric Detection"
Biomed. Chromatogr. 1994 Volume 8, Issue 3 Pages 130-133

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Kazuichi Hayakawa, Atsushi Yamamoto, Akinobu Matsunaga, Eiichi Mizukami, Masayuki Nishimura, Motoichi Miyazaki

Abstract: Previously, we developed a novel detector, a polarized photometric detector for optically active compounds, where two polarizers are set on either side of the UV-visible absorbance detector flow cell. In this paper, we present theoretical considerations on this method with several equations. If the inclined angle of the second polarizer is defined as α (left when α > 0°), the following equation is obtained: ΔAbs = 2 log e.tan α.beta, where ΔAbs is the change in absorbance and beta (magnitude of beta << α) is the angle of rotation of light passing through the cell containing the optically active compound. This equation suggests that ΔAbs is proportional to the analyte concentration and that the dextro- and laevorotatory compounds are detected as positive and negative absorbance changes, respectively. The theoretical maximum signal to noise (S/N) ratio is obtained when α = 45° (= 0.8 rad) and the smallest detection limit is 5 x 10^-5° (S/N = 3) when the path length of the flow cell is 10 mm. This detector was successfully used in flow injection analysis (FIA) as well as HPLC for optically active compounds.
Drugs Fructose Sucrose Pharmaceutical Theory

"Chiral Analysis Based On Polarimetric Detection"
Trends Anal. Chem. 1993 Volume 12, Issue 4 Pages 177-184

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David M. Goodall

Abstract: The use of laser polarimetry for chiral detection in HPLC and flow injection analysis is reviewed. (29 references).
Review