TY - JOUR
T1 - Liquid-Phase Microextraction or Electromembrane Extraction?
AU - Wan, Libin
AU - Lin, Bin
AU - Zhu, Ruiqin
AU - Huang, Chuixiu
AU - Pedersen-Bjergaard, Stig
AU - Shen, Xiantao
PY - 2019/7/2
Y1 - 2019/7/2
N2 - Isolation of substances by liquid-phase microextraction (LPME) or electromembrane extraction (EME) is becoming more and more important in analytical chemistry. However, the understanding of the mass transfer in LPME and EME is limited, especially for highly concentrated samples. In this work, the mass transfer in LPME and EME from aqueous samples (0.5-200 mg L-1) was studied in terms of recovery, equilibrium time, flux, and mass transfer capacity. In both EME and LPME, high recoveries were achieved at low analyte concentration, and the recoveries decreased at high analyte concentration. For EME, the loss in recovery was partly compensated by increasing the extraction voltage (from 50 to 200 V), while the LPME recovery at high analyte concentration was improved by increasing the extraction time (from 30 to 180 min). EME was superior in terms of equilibrium time and flux, while LPME provided much higher mass transfer capacity especially for highly concentrated samples. Moreover, the recovery was much more sensitive to high analyte concentrations in EME than in LPME, and the EME recovery decreased significantly above 50 mg L-1, indicating that LPME could be used to isolate analytes in a wider concentration range than EME. We believe that this fundamental study will be of great importance for the selection of a suitable membrane-based microextraction technique.
AB - Isolation of substances by liquid-phase microextraction (LPME) or electromembrane extraction (EME) is becoming more and more important in analytical chemistry. However, the understanding of the mass transfer in LPME and EME is limited, especially for highly concentrated samples. In this work, the mass transfer in LPME and EME from aqueous samples (0.5-200 mg L-1) was studied in terms of recovery, equilibrium time, flux, and mass transfer capacity. In both EME and LPME, high recoveries were achieved at low analyte concentration, and the recoveries decreased at high analyte concentration. For EME, the loss in recovery was partly compensated by increasing the extraction voltage (from 50 to 200 V), while the LPME recovery at high analyte concentration was improved by increasing the extraction time (from 30 to 180 min). EME was superior in terms of equilibrium time and flux, while LPME provided much higher mass transfer capacity especially for highly concentrated samples. Moreover, the recovery was much more sensitive to high analyte concentrations in EME than in LPME, and the EME recovery decreased significantly above 50 mg L-1, indicating that LPME could be used to isolate analytes in a wider concentration range than EME. We believe that this fundamental study will be of great importance for the selection of a suitable membrane-based microextraction technique.
UR - http://www.scopus.com/inward/record.url?scp=85067934040&partnerID=8YFLogxK
U2 - 10.1021/acs.analchem.9b00946
DO - 10.1021/acs.analchem.9b00946
M3 - Journal article
C2 - 31141346
AN - SCOPUS:85067934040
SN - 0003-2700
VL - 91
SP - 8267
EP - 8273
JO - Analytical Chemistry
JF - Analytical Chemistry
IS - 13
ER -