Generation of electrospray from a solution predeposited on optical fibers coiled with a platinum wire

This study examines the feasibility of generating electrospray directly fro m the tip of two optical fibers bound together with Teflon tape. This appro ach does not require a capillary and syringe pump. The electrospray source is simply constructed by coiling the two optical fibers with a platinum (Pt ) wire. The optical fibers extend beyond the Pt coil for approximately 1 cm . The sample solution is predeposited on the Pt coil by a micropipette. As the high voltage required for electrospray is applied to the coil, the samp le solution moves along the grooves between the two optical fibers. A stabl e electrospray is subsequently generated at the tip of the fibers. The mass spectra of insulin, lysozyme, and ubiquitin are exactly the same as those obtained by conventional electrospray using a capillary and syringe pump. R apid determination of the active ingredient in a tablet by this technique i s demonstrated. (C) 2000 American Society for Mass Spectrometry.