Integrated dc Pump/electrospray
By fixing a DC electrospray to the end of an electro-osmotic micropump, we have developed a new nanospray that can be used as a front end for mass spectrometers. The micropump uses a silica monolith as the working medium and a Nafion ® membrane capillary. The use of these two materials gives the Integrated DC Pump/Electrospray several distinct advantages over currently available nanosprays including:
• Precise control of the fluid flow rate, since advection carries the sample.
• The ability to analyze biological samples, because the silica monolith is effective at pumping organic solvents.
• Reduction of clogging through the porous silica monolith.
• Elimination of electrolytic bubbles from the capillary via the Nafion ® membrane.
• Inexpensive, easy fabrication.
The electro-osmotic micropump compared to a U.S. quarter. The pump provides precise control of flow rate by variation in voltage.
The stable Taylor Cone produced by the electrospray emits nano-sized charged droplets.
When hooked in series with the micropump, the electrospray is a potential front end for mass spectrometers.