Selectivity and efficiency of electromembrane extraction of polar bases with different liquid membranes—Link to analyte properties

Abstract

In the present fundamental study, selectivity and efficiency of electromembrane extraction of 50 polar basic substances (−6.7 < log P < +1.0) was systematically studied for ten different supported liquid membranes. For each model substance, 23 molecular descriptors were collected and these were investigated as potential parameters for understanding of extraction efficiency and selectivity by means of partial least squares regression. Overall, a highly aromatic deep eutectic solvent composed of coumarin and thymol with addition of 2% ionic carrier (di(2‐ethylhexyl) phosphate) provided the highest extraction efficiency with an average extraction yield of 69% from pure water samples, 55% from plasma, and 62% from urine. With this solvent system, ionic, cation‐π, and π‐π interactions between the supported liquid membrane and analytes were dominant. Supported liquid membranes without aromaticity, however, operated primarily based on hydrogen‐bonding interactions. This is the first time the relationship between analyte properties, solvent composition, and extraction yield has systematically been studied for polar bases in electromembrane extraction. This new knowledge represents a first step toward enabling future development and optimization of electromembrane extraction systems for polar bases based on rational design, rather than trial‐and‐error approaches.

Determination of amphetamine enantiomers in urine by conductive vial electromembrane extraction and ultra‐high performance supercritical fluid chromatography tandem mass spectrometry

“…DEHP is an anionic (pKa = 2) carrier, and analyte transport across the SLM is facilitated through formation of ion pairs 29 . Contrarily, DEHPi is a neutral compound and analyte interaction occurs mainly through strong hydrogen bond interactions 30 . The DEHPi+NPOE (1:1) mixture was recently found to be effective in EME of amphetamines from breast milk 31 and resulted in a recovery of 74% in the current experiment.…”

“…29 Contrarily, DEHPi is a neutral compound and analyte interaction occurs mainly through strong hydrogen bond interactions. 30 The DEHPi+NPOE (1:1) mixture was recently found to be effective in EME of amphetamines from breast milk 31 and resulted in a recovery of 74% in the current experiment. The presented results are coherent with previous EME of amphetamine from plasma, urine, and breast milk, where amphetamine was better extracted when NPOE was mixed with other compounds 31,32 or accompanied by modifications of the acceptor.…”

Electromembrane extraction of clenbuterol from swine urine for monitoring illegal use in livestock

“…To date, EME has been conducted using several different organic solvents as the SLMs, such as ethers, alcohols, ketones, and so on [30][31][32][33]. In most previous literature for EME of non-polar basic analytes (log p > 2.5), NPOE has been the most frequently and commonly used organic solvent as the SLM [34][35][36][37]. Since the log p-value of clenbuterol is appropriately 2.63, extraction of clenbuterol was first performed using NPOE as the SLM for 20 min at 120 V. The result revealed that NPOE provided highly effective recovery for clenbuterol and the EME system was highly stable with the system current lower than 50 μA.…”

Comparison of the applicability of electromembrane extraction and liquid‐phase microextraction for extraction of non‐polar basic drugs from different biological samples: Using clozapine as the model analyte

“…Similar to SLM-LPME, the analytes in the acceptor phase were ionized to prevent back-extraction [11]. So far, EME has been employed to separate substances in diverse biological samples [12][13][14][15]. For example, Hansen et al extracted 50 polar basic substances from water samples, plasma, and urine [12].…”

“…So far, EME has been employed to separate substances in diverse biological samples [12][13][14][15]. For example, Hansen et al extracted 50 polar basic substances from water samples, plasma, and urine [12]. Aladaghlo et al used EME to extract sertraline from urine [16].…”