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Mass transfer resistance in a liquid‐phase microextraction employing a single hollow fiber under unsteady‐state conditions
Author(s) -
Kumrić Ksenija R.,
Vladisavljević Goran T.,
Đorđević Jelena S.,
Jönsson Jan Åke,
TrtićPetrović Tatjana M.
Publication year - 2012
Publication title -
journal of separation science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.72
H-Index - 102
eISSN - 1615-9314
pISSN - 1615-9306
DOI - 10.1002/jssc.201200497
Subject(s) - analyte , mass transfer , extraction (chemistry) , acceptor , mass transfer coefficient , analytical chemistry (journal) , chromatography , chemistry , phase (matter) , fiber , organic chemistry , physics , condensed matter physics
In this study, the mass transport resistance in liquid‐phase microextraction ( LPME ) in a single hollow fiber was investigated. A mathematical model has been developed for the determination of the overall mass transfer coefficient based on the acceptor phase in an unsteady state. The overall mass transfer coefficient in LPME in a single hollow fiber has been estimated from time‐dependent concentration of extracted analyte in the acceptor phase while maintaining a constant analyte concentration in the donor phase. It can be achieved either using a high volume of donor to acceptor phase ratio or tuning the extraction conditions to obtain a low‐enrichment factor, so that the analyte concentration in the sample is not significantly influenced by the mass transfer. Two extraction systems have been used to test experimentally the developed model: the extraction of L u(III) from a buffer solution and the extraction of three local anesthetics from a buffer or plasma solution. The mass transfer resistance, defined as a reciprocal values of the mass transfer coefficient, was found to be 1.2 × 10 3 cm− 1 min for L u(III) under optimal conditions and from 1.96 to 3.3 × 10 3 cm− 1 min for the local anesthetics depending on the acceptor pH and the hydrophobicity of the drug.