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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Liquid membrane

Classification: Membrane -> Liquid membrane

Citations 5

"Indirect Determination Of The Pesticide Dimethoxydithiophosphate In An FIA - AAS System With Liquid - Liquid Back-extraction"
Talanta 1991 Volume 38, Issue 8 Pages 857-861
Oroncio Jimenez de Blas, Jose Luis Pereda de Paz and Jesus Hernandez Mendez

Abstract: In the cited FIA - AAS system (details and diagram given) dimethoxydithiophosphate (I) was shaken with 0.01 M nitric acid, CHCl3 and an excess of Cu for 2 min. The organic extract was decanted, the Cu(I)2 complex formed was extracted (x 2) into CHCl3 and Cu was continuously back-extracted into 0.2 M NH4+ - NH3 buffer (pH 10). The extract was injected into a carrier stream of water and Cu was determined by AAS at 324.8 nm. The detection limit was 0.39 ppm of I with a coefficient of variation (n = 9) of 1.6%. Results were comparable to those obtained by standard methods. Interference from Fe and Bi was eliminated by adding an excess of Cu; some thiophosphate pesticides interfered. The method was applied in the determination of malathion in an agricultural formulation.
Pesticides, dimethoxydithiophosphate Agricultural Spectrophotometry Sample preparation

"Aqueous/aqueous Extraction By Means Of A Liquid Membrane For Sample Cleanup And Preconcentration Of Amines In A Flow System"
Anal. Chem. 1986 Volume 58, Issue 13 Pages 2714-2723
Gudjon Audunsson

Abstract: A new configuration for sample cleanup and enrichment of amines in a flow system Is suggested In which the sample passes a liquid membrane whereupon the analyte of interest is released and trapped in a stagnant acceptor phase on the other side. The resulting plug of analyte is then swept from the membrane separator to detection. The mass transfer across the ItquM membrane is discussed theoretically as well as the Influence of transport on the acceptor concentration profile. The effect of sample volume, support matrix, types of immobilized solvents, donor flow rate, and partition coefficients of analytes between donor phase and membrane phase on enrichment factor and separation Is demonstrated and the results are compared with theoretical predictions.
Amines Spectrophotometry Sample preparation

"Separation Of Titanium And Iron In Brines By Solid Supported Liquid Membrane Using Tributyl Phosphate As Carrier"
Anal. Lett. 1991 Volume 24, Issue 10 Pages 1923-1934
Munoz, M.;Valiente, M.

Abstract: Use of a supported liquid membrane to separate mixtures of Ti(V) and Fe(III) in highly concentrated aqueous chloride is described. TBP was used as the extracting agent with solution containing Mg(NO3)2 and HCl as the stripping phase. The supporting liquid membrane was prepared by impregnating the microporous laminar support with the organic solution containing the extractant. The transport of Ti and Fe through the liquid membrane was monitored by online colorimetry using flow injection analysis. The effects of hydrodynamic conditions, membrane area, metal concentration, extractant concentration, pH and chloride concentration in the feed solution was investigated. A model was presented to describe the liquid membrane system.
Iron Titanium Environmental Sample preparation

"Application Of A Tubular Liquid Membrane To Ethanol Sensing By The Flow Injection Technique"
Bunseki Kagaku 1995 Volume 44, Issue 11 Pages 961-964
Ando, M.;Okubo, M.;Kato, T.;Okada, K.;Tokumoto, J.;Okura, T.

Abstract: The sample (3 ml) was injected into a carrier stream of water, which flowed (2 ml/min) round the outside of a porous ceramic tube (6.5 cm x 1 mm i.d., 2.1 mm o.d.) that was impregnated with methyl hydrogen polysiloxane to form a membrane. Ethanol from the sample diffused through the membrane into a stream of water that flowed through the tube in the opposite direction to the carrier stream, and the resulting defocusing of a laser beam transmitted through the tube was measured. Although the measured drop in optical power was roughly linearly correlated with the sample ethanol concentration [up to 30% (v/v)], the reproducibility was unsatisfactory. The application of tubular liquid membrane to an ethanol sensing device was tried using FIA. The membrane was formed by impregnating methyl hydrogene polysiloxan (MHPS) in the porous wall of a ceramic tube. When the tube containing water was immersed in an aqueous ethanol solution, the ethanol dissolved in MHPS and diffused into the water, forming a radial gradient of ethanol concentration. A laser beam transmitted through the tube was expanded by concave-lens effect. The drop in power density of the transmitted beam was roughly correlated with the ethanol concentration. However, reproducibility of data was unsatisfactory, possibly due to disturbance of the boundary between the ethanol solution and carrier water.
Ethanol Spectrometry

"Multisolute Extraction Of Organic-acids By Emulsion Liquid Membranes. 2. Continuous-flow Experiments And Models"
J. Memb. Sci. 1990 Volume 53, Issue 1-2 Pages 105-126
C. C. Wand and A. L. Bunge

Abstract: This paper describes continuous flow mixer-settler emulsion liquid membrane extractions of phenol and binary mixtures of m-cresol and benzoic acid. The multisolute batch extraction models presented in the first paper are extended to the continuous flow configuration. For the experimental systems in this study, the reversible reaction approach correctly reflected solute competition for reagent, while the advancing front approach did not.
Sample preparation