Parallel electromembrane extraction in the 96-well format.
The repeatability and extraction recoveries of parallel electromembrane extraction (Pa-EME) was thoroughly investigated in the present project. Amitriptyline, fluoxetine, and haloperidol were isolated from eight samples of pure water, undiluted human plasma, and undiluted human urine, respectively; in total 24 samples were processed in parallel. The repeatability was found to be independent of the different sample matrices (pure water samples, human plasma, and water) processed in parallel, although the respective samples contained different matrix components. In another experiment seven of the 24 wells were perforated. Even though the perforation caused the total current level in the Pa-EME setup to increase, the intact circuits were unaffected by the collapse in seven of the circuits. In another approach, exhaustive extraction of amitriptyline, fluoxetine, and haloperidol was demonstrated from pure water samples. Amitriptyline and haloperidol were also isolated exhaustively from undiluted human plasma samples; the extraction recovery of fluoxetine from undiluted human plasma was 81%. Finally, the sample throughput was increased with the Pa-EME configuration. The extraction recoveries were investigated by processing 1, 8, 68, or 96 samples in parallel in 10min; neither the extraction recoveries nor the repeatability was affected by the total numbers of samples. Eventually, the Pa-EME was combined with ultra performance liquid chromatography (UPLC) to combine high-throughput sample preparation with high-throughput analytical instrumentation. The aim of the present investigation was to demonstrate the potential of electromembrane extraction as a high throughput sample preparation platform; and hopefully to increase the interest for EME in the bioanalytical field to solve exisiting and novel analytical challenges.
School of Pharmacy, University of Oslo, PO Box 1068, Blindern, Oslo 0316, Norway.
Lars Erik Eng
LE
Eibak
School of Pharmacy, University of Oslo, PO Box 1068, Blindern, Oslo 0316, Norway.
Knut Einar
KE
Rasmussen
School of Pharmacy, University of Oslo, PO Box 1068, Blindern, Oslo 0316, Norway; Norwegian Institute of Public Health, Division of Forensic Sciences, PO Box 4404, Nydalen, Oslo, Norway.
Elisabeth Leere
EL
Oiestad
School of Pharmacy, University of Oslo, PO Box 1068, Blindern, Oslo 0316, Norway; School of Pharmaceutical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Universitetsparken 2, Copenhagen 2100, Denmark.
Stig
S
Pedersen-Bjergaard
School of Pharmacy, University of Oslo, PO Box 1068, Blindern, Oslo 0316, Norway. Electronic address: astrid.gjelstad@farmasi.uio.no.
Astrid
A
Gjelstad
D000639:Amitriptyline / Q000737:chemistry / Q000302:isolation & purification*; D002851:Chromatography, High Pressure Liquid; D055664:Electrochemical Techniques / Q000295:instrumentation*; D005473:Fluoxetine / Q000737:chemistry / Q000302:isolation & purification*; D006220:Haloperidol / Q000737:chemistry / Q000302:isolation & purification*; D057166:High-Throughput Screening Assays / Q000295:instrumentation; D006801:Humans; D013058:Mass Spectrometry; D015394:Molecular Structure
D005473:Fluoxetine; D000639:Amitriptyline; D006220:Haloperidol
96-Well format; Biological matrices; Electromembrane extraction; High throughput sample preparation; Supported liquid membranes; Ultra performance liquid chromatography