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
Website: @unf

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Organic compound

Classification: Organic compound -> ethanol

Citations 8

"Spectrophotometric Flow Injection Determination Of Chloride In Ethanol"
Anal. Chim. Acta 1981 Volume 130, Issue 2 Pages 409-413
F. J. Krug, L. C. R. Pessenda, E. A. G. Zagatto, A. O. Jacintho and B. F. Reis

Abstract: A flow injection procedure is described for the spectrophotometric determination of chloride in ethanol, based on the mercury(II) thiocyanate-iron(III) reaction. Effects of reagent composition and ethanol content of the sample are investigated in detail. The proposed system can analyze 120 samples of ethanol (94-100% v/v) per hour, with a relative standard deviation lower than 1%, when the chloride content ranges from 0.1-6.0 ppm. Recoveries of ~96% are found.
Chloride Spectrophotometry Apparatus Injector

"Sequential Injections In Flow Systems As An Alternative To Gradient Exploitation"
Anal. Chim. Acta 1985 Volume 173, Issue 1 Pages 289-297
E. A. G. Zagatto, M. F. Giné, E. A. N. Fernandes, B. F. Reis and F. J. Krug

Abstract: Because zone-sampling from a pronouced concentration. gradient (cf. Reis et al., Anal. Abstr., 1981, 41, 2J20; Gine et al., Ibid., 1984, 46, 7G1) is prone to imprecision due to flow fluctuations, sampling from a zone of virtually constant concentration. resulting from the merging of, e.g., three plugs of the sample solution injected simultaneously at different positions into the carrier stream ('sequential injections') has been investigated. Such a zone corresponds to one of the maxima or minima of the resultant concentration. - time profile, and the concentration. corresponding to this zone can be adjusted by varying the lengths of the mixing coils between the injection positions. An injection manifold is described for the determination of Mn in rocks by sequential-injection zone-sampling - AAS; output corresponding to a wide range of concentration. (e.g., 80 to 6000 µg g-1; up to 20 µg mL-1 injected) can be accomodated on a single recorder chart. A manifold is also described for the zone-sampling introduction of standard additions to the sample solution for the determination of Cu in ethanol by flow injection AAS.
Manganese Copper Spectrophotometry Gradient technique Standard additions calibration Zone sampling

"Flow Injection Conductometric Determination Of Acidity In Industrial Hydrated Ethyl Alcohol"
Anal. Chim. Acta 1998 Volume 366, Issue 1-3 Pages 81-85
Orlando Fatibello-Filho* and Maria Teresa Mendes Ribeiro Borges

Abstract: A flow injection (FI) conductometric procedure is proposed for the determination of acidity in industrial 96%(v/v) hydrated ethyl alcohol. The method consists in a single-line system in which an alkaline solution (sodium hydroxide), in excess, was used as carrier. When the sample is inserted in the flow system, it mixes with and partially neutralizes the carrier solution, causing a decrease on the sample zone conductance, proportional to the sample acidity. The best conditions found were an anal. path of 100 cm, injection sample volume of 50 µL, temperature of 20°C and 1.0 x 10^-3 mol L-1 sodium hydroxide as reagent carrier. With a single-channel manifold, 96%(v/v) ethyl alcohol acidity was determined in the 0.60-15.00 mg HOAc/100 mL concentration. range (expressed as acetic acid) (calibration graph: H = -49.141-2.447C, r = 0.9989, where H is the peak height in mm and C is the acetic acid concentration in 96%(v/v) ethyl alcohol in mg HOAc/100 mL) with a detection limit (three times the signal blank/slope) of 0.51 mg HOAc/100 mL. The throughput was 120 results h-1 and potassium chloride solution up to concentration of 11.48 mg KCl/100 mL injected together 2.40 mg HOAc/100 mL 96% v/v Et alcohol solution does not cause any effect in the conductometric response. A 2.40 mg HOAc/100 mL 96%(v/v). Ethyl alcohol solution gave a relative standard deviation <1% (n = 15) and the results obtained for four industrial, hydrated Et alcohol with this procedure are in close agreement with those obtained using the titration procedure (r = 0.9991).
Acidity Conductometry Method comparison Interferences

"Determination Of Water In Ethanol And Acetone By Direct Injection Enthalpimetry Based On The Heat Of Dilution"
Talanta 1984 Volume 31, Issue 1 Pages 82-84
Walace A. De Oliveira and Celio Pasquini

Abstract: Two analytical procedures based on the magnitude of the heat of dilution and direct injection enthalpimetry have been developed for determination of water in ethanol and acetone. The results obtained by means of the heat of dilution were compared with the values given by pycnometry, and gave a relative difference in the range 0.2-3%. The precision depends on the slope of the calibration curve, which varies with the procedure and the concentration of the sample.
Water Enthalpimetry

"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 V&aacute;cha 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

"Near Infrared Detection Of Flow Injection Analysis By Acousto-optic Tunable Filter-based Spectrophotometry"
Anal. Chem. 1996 Volume 68, Issue 6 Pages 971-976
Mauricio S. Baptista, Chieu D. Tran, and Guan-Hong Gao

Abstract: A NIR spectrometer which can serve as a sensitive and universal detector for FIA is described. It included a solid-state acousto-optic tunable filter (AOTF) which allowed a high scanning speed and wavelength accuracy. Collimated incident light was dispersed to monochromatic and spectrally scanned by the AOTF. The diffracted light was split into sample and reference beams, with a flow cell placed in the sample beam. Light intensities were detected by thermoelectrically cooled GaInAs detectors and the signals were amplified and passed to a microcomputer. The recorded spectra were subjected to multivariate calibration methods. The instrument was applied to the determination of water traces in CHCl3 and benzene and water in ethanol. The instrumentation development of a near-infrared (near-IR) spectrophotometer based on an acoustooptic tunable filter (AOTF) and its application as a detector for flow injection analysis (FIA) are reported. In addition to being compact and all solid state, this AOTF- based instrument is very sensitive, has high resolution, and can be rapidly scanned. The latter advantage make it uniquely suited as a detector for FIA, in that it can rapidly record the whole near-IR absorption spectrum of a mixture passing through the FIA flow cell. Subsequent treatment of the recorded spectra with multivariate calibration methods makes it possible to use the FIA, for the first time, for such applications as the simultaneous determination of trace amounts of water and benzene in ethanol. Because all organic compounds absorb light in the near-infrared region, this AOTF-based near-IR detector can serve as a universal detector for FIA; as a consequence, applications of the FIA techniques can be expanded to other areas which are not possible otherwise.
Water Benzene Spectrophotometry Acousto optic tunable filter Computer Multivariate calibration

"Amperometric Systems For The Determination Of Oxidase Enzyme Dependent Reactions By Continuous-flow And Flow Injection Analysis"
J. Autom. Methods Manag. Chem. 1980 Volume 2, Issue 4 Pages 189-194

Abstract: The article describes electrode systems which were incorporated into a flow system to amperometrically or bioamperometrically detect I in the presence of excess I-. Both continuous-flow analysis and flow injection analysis systems were used to measure H2O2 and also EtOH. Alcohol oxidase was immobilized by covalent attachment via glutaraldehyde on silanized glass beads and also on the inside walls of nylon tubing.
Ethanol Hydrogen peroxide Iodide Amperometry Biamperometry Immobilized enzyme Glass beads Nylon

"Determination Of The Alcohol Denaturants Denatonium Benzoate (Bitrex) And Diethyl Phthalate By Direct Flow Injection APCI-MS Analysis"
J. High Resolut. Chromatogr. 1997 Volume 20, Issue 6 Pages 321-324
Ma Elena Alvarez-Pi&ntilde;eiro, Ma Jos&eacute;a L&oacute;pez De Alda-Villaiz&aacute;n, Perfecto Paseiro-Losada, Ma Asunci&oacute;n Lage-Yusty

Abstract: The recently developed tandem technique, mass spectroscopy with atmospheric-pressure chemical ionization (APCI-MS) coupled with direct flow injection, was applied to the determination of Bitrex (denatonium benzoate) and diethyl phthalate in ethanol. The compounds were identified from their total-ion chromatograms (m/z 50-500) and, simultaneously, quantified using selected-ion chromatograms recorded at m/z 223 for diethyl phthalate and m/z 325 for Bitrex. Operating conditions were optimized for soft ionization (positive ion-mode) with fragmentation limited to that necessary for analyte identification, which was by the external-standard method. Calibration curves were rectilinear in the concentration ranges 2-30 µg mL-1 (Bitrex) and 0.075-1.2% v/v (diethyl phthalate); measurement precision (RSDs were 11.48% for Bitrex and 2.22% for diethyl phthalate), and detection limits (0.017 µg mL-1 and 0.010% v/v, respectively) were adequate for simultaneous quantitation and with high sensitivity. The lack of any sample pretreatment and the use of flow injection analysis meant that the procedure was more straightforward and rapid than previously reported methods.
Phthalate, diethyl Mass spectrometry Method comparison Optimization Standard method