title: Monitoring of vancomycin in human plasma via portable microchip electrophoresis with contactless conductivity detector and multi-stacking strategy.
abstract: A portable microchip electrophoresis (MCE) coupled with on-chip contactless conductivity detection (C4D) system was evaluated for the determination of vancomycin in human plasma. In order to enhance the detection sensitivity, a new online multi-stacking preconcentration technique based on field-enhanced sample injection (FESI) and micelle-to-solvent stacking (MSS) was developed and implemented in MCE-C4D system equipped with a commercially available double T-junction glass chip. The cationic analytes from the two sample reservoirs were injected under FESI conditions and subsequently focused by MSS within the sample-loading channel. The proposed multi-stacking strategy was verified under a fluorescence microscope using Rhodamine 6G as the model analyte and a sensitivity enhancement factor (SEF) of up to 217 was achieved. The developed approach was subsequently implemented in the aqueous-based MCE, coupled to C4D in order to monitor the targeted antibiotic (in this case, vancomycin) present in human plasma samples. The multi-stacking and analysis time for vancomycin were 50s and 250s respectively, with SEF of approximately 83 when compared to typical gated injection. The detection limit of the method for vancomycin was 1.2μg/mL, with intraday and interday repeatability RSDs of 2.6% and 4.3%, respectively. Recoveries in spiked human plasma were 99.0%-99.2%.
authors.affiliation: Centre for Sustainable Nanomaterials, Ibnu Sina Institute for Scientific and Industrial Research, Universiti Teknologi Malaysia, 81310, UTM, Johor Bahru, Johor, Malaysia; Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, 81310 UTM, Johor Bahru, Johor, Malaysia.
authors.forename: Kah Chun
authors.initials: KC
authors.lastname: Chong
authors.affiliation: Centre for Sustainable Nanomaterials, Ibnu Sina Institute for Scientific and Industrial Research, Universiti Teknologi Malaysia, 81310, UTM, Johor Bahru, Johor, Malaysia; Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, 81310 UTM, Johor Bahru, Johor, Malaysia.
authors.forename: Lee Yien
authors.initials: LY
authors.lastname: Thang
authors.affiliation: Australian Centre for Research on Separation Science, School of Physical Sciences - Chemistry, University of Tasmania, 7001, Hobart, Tasmania, Australia; Department of Chemistry, Ateneo de Manila University, Katipunan Ave., Loyola Heights, Quezon City, 1108, Philippines. Electronic address: jquirino@utas.edu.au.
authors.forename: Joselito P
authors.initials: JP
authors.lastname: Quirino
authors.affiliation: Centre for Sustainable Nanomaterials, Ibnu Sina Institute for Scientific and Industrial Research, Universiti Teknologi Malaysia, 81310, UTM, Johor Bahru, Johor, Malaysia; Department of Chemistry, Faculty of Science, Universiti Teknologi Malaysia, 81310 UTM, Johor Bahru, Johor, Malaysia. Electronic address: hhsee@ibnusina.utm.my.
authors.forename: Hong Heng
authors.initials: HH
authors.lastname: See
mesh_terms: D000900:Anti-Bacterial Agents / Q000097:blood*; D002412:Cations; D046209:Electrophoresis, Microchip / Q000379:methods; D006801:Humans; D057230:Limit of Detection; D008823:Micelles; D012997:Solvents; D014640:Vancomycin / Q000097:blood*
chemical_list: D000900:Anti-Bacterial Agents; D002412:Cations; D008823:Micelles; D012997:Solvents; D014640:Vancomycin
keywords: Contactless conductivity detection; Field-enhance sample injection; Micelle-to-solvent stacking; Microchip electrophoresis; Vancomycin