title: Electrowetting on dielectric actuation of droplets with capillary electrophoretic zones for MALDI mass spectrometric analysis.
abstract: An automated fraction collection interface was developed for coupling CE with MALDI-MS. This fraction collection approach is based on the electrowetting on dielectric (EWOD) phenomenon performed on a digital microfluidic (DMF) board; it does not rely on a MALDI spotter. In this study, a four-peptide mixture was used as a sample test, and the separations were conducted in a portable CE instrument with a 150 μm o.d. × 50 μm i.d. capillary and a contactless conductivity detector. The CE instrument was interfaced with a robust DMF board. The CE fractions were directly deposited onto the DMF board at predetermined locations prior to MALDI analysis. The series of experiments determined the lowest concentration that produces a measurable MALDI signal. The concentrations were 0.25, 0.5, 0.05, and 0.05 nmol for bradykinin, angiotensin, ACTH (18-39), and insulin, respectively. The contactless conductivity detector limit of detection for the same analytes was 2.5 μmol.
authors.affiliation: Institute of Chemistry, Tallinn University of Technology, Tallinn, Estonia.
authors.forename: Jelena
authors.initials: J
authors.lastname: Gorbatsova
authors.forename: Maria
authors.initials: M
authors.lastname: Borissova
authors.forename: Mihkel
authors.initials: M
authors.lastname: Kaljurand
mesh_terms: D019075:Electrophoresis, Capillary / Q000295:instrumentation* / Q000379:methods*; D058874:Electrowetting / Q000379:methods*; D006801:Humans; D036361:Peptide Hormones / Q000032:analysis / Q000302:isolation & purification; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization / Q000379:methods*
chemical_list: D036361:Peptide Hormones