A Mathematical Model for Kinetic Study of Analyte Permeation from Both Liquid and Gas Phases through Hollow Fiber Membranes into Vacuum

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• 作者：Alexey A. Sysoev
• 刊名：Analytical Chemistry
• 出版年：2000
• 出版时间：September 1, 2000
• 年：2000
• 卷：72
• 期：17
• 页码：4221 - 4229
• 全文大小：156K
• 年卷期：v.72,no.17(September 1, 2000)
• ISSN：1520-6882

文摘

A mathematical model and a Matlab-5 computer codehave been developed to study the dynamic response ofthe hollow fiber membrane probe. The depletion layerformation at the sample/membrane interface is taken intoconsideration by the mathematical model for the liquidmobile phase. The code produces concentration profileswithin a sample feed stream and in the membrane. Fluxvalues at the vacuum side of the membrane can also becalculated as a function of time. The method can beapplied both for gas and liquid feed streams. Concentration profiles in a mobile phase and the flux of analytesthrough the hollow fiber membrane inlet have beenstudied with this simulation technique as a function ofthe liquid-phase flow rate. The influence of the formationof a layer of the analyte depletion during the dynamicresponse has been considered. The shape of the depletedlayer and selectivity of permeation from a liquid mobilephase through the membrane into the vacuum are shownto be dependent on the mobile-phase flow rate. In addition, for studied conditions, formation of a depletion layeris demonstrated to be fast compared with membranediffusion. Thus, if a homogeneous aqueous sample iscoming through the inlet cross-section of a hollow fibermembrane containing pure water, the response timemostly depends on analyte diffusivity in the membrane.However, if the aqueous sample is coming through theinlet cross-section of a hollow fiber membrane containingclean air, response time also depends on equilibriumanalyte concentration in the depletion layer.