Parallel electromembrane extraction in a multiwell plate

Abstract

This paper describes the concept of parallel electromembrane extraction (Pa-EME) with flat membranes in a multiwell format for the first time. The setup is based on a multiwell plate and provided simultaneous and selective isolation, cleanup, and enrichment of several human plasma samples as well as LC-MS-compatible extracts within 8 min of extraction. Undiluted human plasma samples spiked with four antidepressant drugs were added to separate wells in the donor plate. Subsequently, the samples were extracted with Pa-EME. The four drugs migrated electrokinetically from undiluted human plasma through a flat polypropylene membrane impregnated with 2-nitrophenyl octyl ether, and were isolated into formic acid. Extraction time, extraction voltage, agitation rate, sample volume, and acceptor solution volume were all optimized with an experimental design. The optimal conditions were as follows: The agitation rate was 1,040 rpm, and an extraction voltage of 200 V was applied. The sample volume and acceptor solution volume was 240 and 70 μL, respectively. The extraction was continued for 8 min. Eventually, the extracts were analyzed by LC-MS/MS. The combination of Pa-EME with LC-MS/MS provided quantitation limits below the therapeutic level and reported relative standard deviations in the range 5-13 %. Linear calibration curves were obtained for all analytes, and the correlation coefficients were above 0.9974 in the range 1-400 ng mL(-1). The drug concentrations from two subjects treated with quetiapine and sertraline were successfully determined with Pa-EME combined with LC-MS/MS. Post-column infusion experiments demonstrated that Pa-EME provided extracts free from interfering matrix components.

Combination of Electromembrane Extraction and Liquid-Phase Microextraction in a Single Step: Simultaneous Group Separation of Acidic and Basic Drugs

“…18,25,32 The operational parameters used for EME in the current work were based on previous experience. 25 LPME was used to extract acidic analytes from low pH sample to high pH acceptor solution.…”

Sample preparation for polar metabolites in bioanalysis

“…Interferents such as proteins, salts or phospholipids do not cross the SLM and generally a low matrix effect such as ionization alteration is observed. 37,38 Because EME can extract either cations or anions, it can be an effective fractionation method according to the charge of the metabolite, in the case of very complex matrices. Nowadays, EME is largely used for the extraction of moderately lipophilic ionized compounds such as drugs and drug metabolites, 39,40 inorganic ions, 41,42 from a large variety of matrices such as plasma and waste water.…”

Determination of Non‐Steroidal Anti‐Inflammatory Drugs in Urine by HPLC–UV/Vis Analysis Coupled with Electromembrane Extraction

“…Although HF‐LPME is less time‐consuming than SPE and LLE, the corresponding partitioning is still relatively slow, inspiring us to reduce analysis time by investigating electromembrane extraction (EME) . During EME, an electrical field is applied across the impregnated organic solvent in the wall of a hollow fiber (supported liquid membrane, SLM) to extract charged analytes from the aqueous sample (donor solution) into a buffered aqueous solution (acceptor solution) through the SLM .…”