title: Automation of static and dynamic non-dispersive liquid phase microextraction. Part 2: Approaches based on impregnated membranes and porous supports.
abstract: A critical overview on automation of modern liquid phase microextraction (LPME) approaches based on the liquid impregnation of porous sorbents and membranes is presented. It is the continuation of part 1, in which non-dispersive LPME techniques based on the use of the extraction phase (EP) in the form of drop, plug, film, or microflow have been surveyed. Compared to the approaches described in part 1, porous materials provide an improved support for the EP. Simultaneously they allow to enlarge its contact surface and to reduce the risk of loss by incident flow or by components of surrounding matrix. Solvent-impregnated membranes or hollow fibres are further ideally suited for analyte extraction with simultaneous or subsequent back-extraction. Their use can therefore improve the procedure robustness and reproducibility as well as it "opens the door" to the new operation modes and fields of application. However, additional work and time are required for membrane replacement and renewed impregnation. Automation of porous support-based and membrane-based approaches plays an important role in the achievement of better reliability, rapidness, and reproducibility compared to manual assays. Automated renewal of the extraction solvent and coupling of sample pretreatment with the detection instrumentation can be named as examples. The different LPME methodologies using impregnated membranes and porous supports for the extraction phase and the different strategies of their automation, and their analytical applications are comprehensively described and discussed in this part. Finally, an outlook on future demands and perspectives of LPME techniques from both parts as a promising area in the field of sample pretreatment is given.
authors.affiliation: Department of Medical and Clinical Biophysics, Faculty of Medicine, University of P.J. Šafárik in Košice, SK-04011 Košice, Slovakia. Electronic address: michal.alexovic@upjs.sk.
authors.forename: Michal
authors.initials: M
authors.lastname: Alexovič
authors.affiliation: Department of Analytical Chemistry, Faculty of Pharmacy, Charles University in Prague, CZ-50005 Hradec Králové, Czech Republic.
authors.forename: Burkhard
authors.initials: B
authors.lastname: Horstkotte
authors.affiliation: Department of Analytical Chemistry, Faculty of Pharmacy, Charles University in Prague, CZ-50005 Hradec Králové, Czech Republic.
authors.forename: Petr
authors.initials: P
authors.lastname: Solich
authors.affiliation: Department of Medical and Clinical Biophysics, Faculty of Medicine, University of P.J. Šafárik in Košice, SK-04011 Košice, Slovakia.
authors.forename: Ján
authors.initials: J
authors.lastname: Sabo
mesh_terms: D001331:Automation; D059627:Liquid Phase Microextraction / Q000379:methods*; D008567:Membranes, Artificial; D016062:Porosity
chemical_list: D008567:Membranes, Artificial
keywords: Automation; Chromatomembrane; Dynamic liquid phase microextraction; Hollow-fibre liquid phase microextraction; Liquid phase microextraction; Miniaturisation; Static liquid phase microextraction; Supported liquid membrane microextraction