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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Organic compound

Classification: Organic compound -> methanol

Citations 3

"Comparison Of Spectrophotometric And Potentiometric Detection For The Determination Of Water Using Karl Fischer Method Under Flow Injection Analysis Conditions"
Anal. Chim. Acta 2000 Volume 420, Issue 1 Pages 133-142
Nathalie Dantan, Steffen Kröning, Wolfgang Frenzel and Stephan Küppers

Abstract: Flow injection procedures for the determination of water in methanol using Karl Fischer method are presented. Both spectrophotometric and potentiometric detection systems were investigated and critically compared with respect to their performance characteristics. A novel tubular differential potentiometric flow through cell has been developed. Using spectrophotometric detection the determination of water at a sampling frequency of about 120 h-1 is possible in the concentration range 0.01-1%. Precision is better than 3% RSD over the entire concentration range. The detectability of the method is severely affected by the presence of water traces in the carrier solvent but with appropriate preventive measures, concentrations as low as 0.002% are accessible. The specifications of the potentiometric variant compare well with the spectrophotometric detection method, yet the former offers slightly better precision but suffers from reduced linear range, Automation of the two methods has been realised and the applicability for on-line monitoring purposes are outlined. Particular emphasis is paid to the calibration problematic. Modified reverse FIA has also been applied and shown to be a simple and reliable way of detecting deviations from nominal values as required in several process control situations.
Water Spectrophotometry Potentiometry Karl Fischer analysis Reverse Process control Calibration Method comparison

"Determination Of Water By Flow Injection Analysis With The Karl Fischer Reagent. Minimization Of Effects Caused By Differences In Physical Properties Of The Samples"
Anal. Chim. Acta 1984 Volume 162, Issue 1 Pages 9-18
Ingrid Nordin-Andersson, Ove Åström and Anders Cedergren

Abstract: Means for overcoming problems arising from large variations in calibration graphs for different types of sample in this method (Kagevall et al., Anal. Abstr., 1982, 43, 1E23) are discussed. The samples analyzed were propan-2-ol, isopropyl acetate, propyl acetate and methanol, and a modified Karl Fischer reagent (containing 4.57 g of iodine, 50 g of SO2 and 80 mL of pyridine, diluted to 1 l with methanol and adjusted to be 6 mM in iodine before use) was used as carrier solution. The best results were obtained by use of a spectrophotometric detector that minimized refractive-index effects, together with peak-area measurements. A single-line arrangement, having a coil reactor, in conjunction with a high flow rate of reagent, was also preferred. Under these conditions, a sample containing 0.1% of water could be analyzed with a coefficient of variation of ~2%.
Water Karl Fischer analysis Spectrophotometry Refractive index

"Determination Of Water In Organic Solvents By Flow Injection Analysis With Karl Fischer Reagent And A Biamperometric Detection System"
Talanta 1988 Volume 35, Issue 1 Pages 59-61
Chen Liang, Pavel Vácha and Willem E. van der Linden

Abstract: A flow injection system and biamperometric flow-through detector (described) were tested for use in the determination of water in organic solvents with use of a pyridine-free Karl Fischer reagent. The calibration graph was rectilinear from 0.03 to 0.11% of water in methanol, ethanol or propan-2-ol. If a membrane separation cell was used in the system, the calibration graph was rectilinear from 0.1 to 2% of H2O.
Water Biamperometry Karl Fischer analysis Detector Membrane