TY - JOUR

T1 - Liquid-phase microextraction in a microfluidic-chip

T2 - high enrichment and sample clean-up from small sample volumes based on three-phase extraction

AU - Payán, María D. Ramos

AU - Jensen, Henrik

AU - Petersen, Nickolaj J.

AU - Hansen, Steen Honoré

AU - Pedersen-Bjergaard, Stig

N1 - Copyright © 2012 Elsevier B.V. All rights reserved.

PY - 2012

Y1 - 2012

N2 - In this work, a microfluidic-chip based system for liquid-phase microextraction (LPME-chip) was developed. Sample solutions were pumped into the LPME-chip with a micro-syringe pump at a flow rate of 3-4µLmin(-1). Inside the LPME chip, the sample was in direct contact with a supported liquid membrane (SLM) composed of 0.2µL dodecyl acetate immobilized in the pores of a flat membrane of polypropylene (25µm thickness). On the other side of the SLM, the acceptor phase was present. The acceptor phase was either pumped at 1µLmin(-1) during extraction or kept stagnant (stop-flow). Amitriptyline, methadone, haloperidol, loperamide, and pethidine were selected as model analytes, and they were extracted from alkaline sample solution, through the SLM, and into 10mM HCl or 100mM HCOOH functioning as acceptor phase. Subsequently, the acceptor phase was either analyzed off-line by capillary electrophoresis for exact quantification, or on-line by UV detection or electrospray ionization mass spectrometry for time profiling of concentrations. The LPME-chip was found to be highly effective, and extraction efficiencies were in the range of 52-91%. When the flow of acceptor phase was turned off during extraction (stop-flow), analyte enrichment increased linearly with the extraction time. After 10min as an example, amitriptyline was enriched by a factor of 42 from only 30µL sample solution, and after 120min amitriptyline was enriched by a factor of 500 from 320µL sample solution. This suggested that the LPME-chip has great potentials for very efficient analyte enrichments from limited sample volumes in the future.

AB - In this work, a microfluidic-chip based system for liquid-phase microextraction (LPME-chip) was developed. Sample solutions were pumped into the LPME-chip with a micro-syringe pump at a flow rate of 3-4µLmin(-1). Inside the LPME chip, the sample was in direct contact with a supported liquid membrane (SLM) composed of 0.2µL dodecyl acetate immobilized in the pores of a flat membrane of polypropylene (25µm thickness). On the other side of the SLM, the acceptor phase was present. The acceptor phase was either pumped at 1µLmin(-1) during extraction or kept stagnant (stop-flow). Amitriptyline, methadone, haloperidol, loperamide, and pethidine were selected as model analytes, and they were extracted from alkaline sample solution, through the SLM, and into 10mM HCl or 100mM HCOOH functioning as acceptor phase. Subsequently, the acceptor phase was either analyzed off-line by capillary electrophoresis for exact quantification, or on-line by UV detection or electrospray ionization mass spectrometry for time profiling of concentrations. The LPME-chip was found to be highly effective, and extraction efficiencies were in the range of 52-91%. When the flow of acceptor phase was turned off during extraction (stop-flow), analyte enrichment increased linearly with the extraction time. After 10min as an example, amitriptyline was enriched by a factor of 42 from only 30µL sample solution, and after 120min amitriptyline was enriched by a factor of 500 from 320µL sample solution. This suggested that the LPME-chip has great potentials for very efficient analyte enrichments from limited sample volumes in the future.

U2 - 10.1016/j.aca.2012.05.023

DO - 10.1016/j.aca.2012.05.023

M3 - Journal article

C2 - 22713916

VL - 735

SP - 46

EP - 53

JO - Analytica Chimica Acta

JF - Analytica Chimica Acta

SN - 0003-2670

ER -