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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Nephelometry

Classification: Nephelometry

Citations 4

"Rapid Determination Of Total Biomass From A Yeast Fermentation Using Sequential Injection"
Analyst 1994 Volume 119, Issue 8 Pages 1807-1812

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P. J. Baxter, G. D. Christian and J. Ruzicka

Abstract: Samples were obtained directly from a feed-batch aerobic fermentation of Saccharomyces cerevisiae and were analyzed without pretreatment. A 38 µL sample was pulled into a holding coil via a multiport valve by means of a peristaltic pump. The sample was delivered to a stirred flow cell (volume 1.7 ml) in a water carrier stream (2.2 ml/min) containing 2 ppm of Brijj-35. The signal was recorded by measuring either total transmitted light or light scattered at 90°C. Diagrams of the sequential-injection manifold and flow cell used are given. The sample range for the assay was from 0.2 to at 800 g/l of biomass. RSD (n not given) were 3%. The total assay time was 4 min.
Biomass Fermentation broth Sequential injection Process monitoring Surfactant Valve

"Theory And Principles Of Flow Injection Analysis"
Anal. Proc. 1981 Volume 18, Issue 6 Pages 267-269

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J. Ruzicka

Abstract: This accurate and versatile technique is capable of sampling rates of up to 200 samples per hour, yet its most valuable asset is the simplicity of the experimental set-up. The method can be used to automate any colorimetric, fluorimetric, nephelometric or other optical instrumental method, provided that the reaction used is sufficiently fast. Furthermore, electrochemical detection, such as potentiometric pH or pCa measurement, can be executed rapidly and reproducibly.
Calcium pH Gradient technique Review Theory

"Highly Water-permeable Type I Alveolar Epithelial Cells Confer High Water Permeability Between The Airspace And Vasculature In Rat Lung"
Proc. Natl. Acad. Sci. USA 1998 Volume 95, Issue 6 Pages 2991-2996

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Leland G. Dobbs*, Robert Gonzalez, Michael A. Matthay, Ethan P. Carter, Lennell Allen, and A. S. Verkman

Abstract: Water permeability measured between the airspace and vasculature in intact sheep and mouse lungs is high. More than 95% of the internal surface area of the lung is lined by alveolar epithelial type I cells. The purpose of this study was to test whether osmotic water permeability (Pf) in type I alveolar epithelial cells is high enough to account for the high Pf of the intact lung. Pf measured between the airspace and vasculature in the perfused fluid-filled rat lung by the pleural surface fluorescence method was high (0.019±0.004 cm/s at 12°C) and weakly temperature-dependent (activation energy 3.7 kcal/mol). To resolve the contributions of type I and type II alveolar epithelial cells to lung water permeability, Pf was measured by stopped-flow light scattering in suspensions of purified type I or type II cells obtained by immunoaffinity procedures. In response to a sudden change in external solution osmolality from 300 to 600 mOsm, the volume of type I cells decreased rapidly with a half-time (t1/2) of 60-80 ms at 10°C, giving a plasma membrane Pf of 0.06-0.08 cm/s. Pf in type I cells was independent of osmotic gradient size and was weakly temperature-dependent (activation energy 3.4 kcal/mol). In contrast, t1/2 for type II cells in suspension was much slower, approximately 1 s; Pf for type II cells was 0.013 cm/s. Vesicles derived from type I cells also had a very high Pf of 0.06-0.08 cm/s at 10°C that was inhibited 95% by HgCl2. The Pf in type I cells is the highest measured for any mammalian cell membrane and would account for the high water permeability of the lung.
Cells Water Stopped-flow

"A Low-Cost Light-Scattering Detector For The Flow-Injection Nephelometric Determination Of Sulfate"
Anal. Sci. 2003 Volume 19, Issue 11 Pages 1495-1498

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Jaroon Jakmunee, Yuthpong Udnan, Richard Morrison, Ronald Beckett, Ian Mckinnon And Kate Grudpan

Abstract: A simple low-cost flow-through light-scattering detector was developed for determining the particle mass concentration in colloidal suspensions. Employing a laser pointer as a light source and a photodiode IC as a light sensor, the detector was shown to have good sensitivity, yet was small and battery operated. The detector was demonstrated to be effective for the flow-injection nephelometric determination of sulfate by precipitation as barium sulfate.
Sulfate Environmental Precipitation Optimization