کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1202934 | 1493691 | 2012 | 7 صفحه PDF | دانلود رایگان |
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).
► Method developed for compartmentalizing electrophoretically separated zones within droplets.
► Fractions droplets were moved by Digital microfluidic actuator into storage tube.
► In storage tube fractions were encapsulated in air.
► Segmented plugs were pumped directly into a spray emitter tip of off-line ESI-MS.
► The concept was proven by analysis of vitamins in standard solution and in commercial formulations.
Journal: Journal of Chromatography A - Volume 1234, 20 April 2012, Pages 9–15