Electrowetting-on-dielectric actuation of droplets with capillary electrophoretic zones for off-line mass spectrometric analysis.
Present article describes a novel technique based on digital microfluidics that allows collecting fractions of interest after electrophoretic separation and detection for further ESI-MS investigation. In this technique, a mixture is injected into a capillary electrophoresis (CE) apparatus, and microliter droplets are generated at the CE outlet at a frequency high enough to fraction each compound into several droplets, compartmentalizing the CE zones into a sequence of droplets. The droplets are transported from the CE outlet to a storage tube inlet using electrowetting-on-dielectric (EWOD) for droplet actuation. By applying a vacuum at the other end of the storage tube, the droplets form a sequence of plugs separated by air gaps. The plugs stored in the tubing are later analyzed using a standalone spectrometric device. Off-line electrospray ionization mass spectrometry (ESI-MS) was used to characterize the corresponding vitamin and was performed by pumping the segmented plugs directly into a spray emitter tip. The technique could be of interest to laboratories without access to well-equipped facilities (e.g. clean-rooms or lab robots).
Institute of Chemistry, Tallinn University of Technology, Akadeemia Tee 15, Tallinn, Estonia.
Jelena
J
Gorbatsova
Maria
M
Borissova
Mihkel
M
Kaljurand
D019075:Electrophoresis, Capillary / Q000295:instrumentation* / Q000379:methods*; D058874:Electrowetting / Q000295:instrumentation*; D004867:Equipment Design; D057230:Limit of Detection; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D014803:Vitamin B Complex / Q000032:analysis
D014803:Vitamin B Complex