TY - JOUR

T1 - Generic Liquid Membranes for Electromembrane Extraction of Bases with Low or Moderate Hydrophilicity

AU - Zhou, Chen

AU - Dowlatshah, Samira

AU - Hay, Anne Oldeide

AU - Schüller, Maria

AU - Pedersen-Bjergaard, Stig

AU - Hansen, Frederik André

N1 - Funding Information: This project has received support from the DIKU–Norwegian Agency for International Cooperation and Quality Enhancement in Higher Education.

PY - 2023

Y1 - 2023

N2 - For the first time, this paper introduces the idea of generic extraction conditions in electromembrane extraction (EME), where the selection of the liquid membrane is based on the charge (z) and hydrophobicity (log P) of the analyte. A broad range of organic solvents were tested as liquid membranes, and 90 basic pharmaceuticals were used as model analytes (−4.2 < log P < 8.1). 2-Nitrophenyl octyl ether (NPOE) was confirmed as a highly efficient liquid membrane for mono- and dibases (+1.0 ≤ z ≤ +2.0) of low polarity in the log P range of 2.2-6.4. This log P range was set as the extraction window (operational range) of NPOE. NPOE provided very high operational stability. At 50 V, the current was at a 1 μA level, and gas formation and drifting pH due to electrolysis were insignificant. 2-Undecanone was discovered as a new and robust alternative. This solvent extracted monobasic analytes (z = +1) in the log P range of 1.0-5.8 and was efficient even for bases of moderate polarity. The current was at the 1-3 μA level when 2-undecanone was operated at 50 V. Tri(pentyl) phosphate emerged as another new alternative for bases in the log P range of 0.5 to 5.5, providing greater selectivity differences. This solvent provided a higher current (30-50 μA), but the EME system stability was not compromised. 2-Undecanone and tri(pentyl) phosphate extracted protonated bases mainly by hydrogen bond interactions. NPOE, on the other hand, extracted based on a combination of hydrogen bond and π-type interactions and was consequently less selective.

AB - For the first time, this paper introduces the idea of generic extraction conditions in electromembrane extraction (EME), where the selection of the liquid membrane is based on the charge (z) and hydrophobicity (log P) of the analyte. A broad range of organic solvents were tested as liquid membranes, and 90 basic pharmaceuticals were used as model analytes (−4.2 < log P < 8.1). 2-Nitrophenyl octyl ether (NPOE) was confirmed as a highly efficient liquid membrane for mono- and dibases (+1.0 ≤ z ≤ +2.0) of low polarity in the log P range of 2.2-6.4. This log P range was set as the extraction window (operational range) of NPOE. NPOE provided very high operational stability. At 50 V, the current was at a 1 μA level, and gas formation and drifting pH due to electrolysis were insignificant. 2-Undecanone was discovered as a new and robust alternative. This solvent extracted monobasic analytes (z = +1) in the log P range of 1.0-5.8 and was efficient even for bases of moderate polarity. The current was at the 1-3 μA level when 2-undecanone was operated at 50 V. Tri(pentyl) phosphate emerged as another new alternative for bases in the log P range of 0.5 to 5.5, providing greater selectivity differences. This solvent provided a higher current (30-50 μA), but the EME system stability was not compromised. 2-Undecanone and tri(pentyl) phosphate extracted protonated bases mainly by hydrogen bond interactions. NPOE, on the other hand, extracted based on a combination of hydrogen bond and π-type interactions and was consequently less selective.

U2 - 10.1021/acs.analchem.3c01052

DO - 10.1021/acs.analchem.3c01052

M3 - Journal article

C2 - 37259537

AN - SCOPUS:85163621749

VL - 95

SP - 8982

EP - 8989

JO - Industrial And Engineering Chemistry Analytical Edition

JF - Industrial And Engineering Chemistry Analytical Edition

SN - 0003-2700

IS - 23

ER -