Microfluidic Devices Connected to Fused-Silica Capillaries with Minimal Dead Volume

Fused-silica capillaries have been connected to microfluidic devices for capillary electrophoresis by drilling into the edge of the device using 200-μm tungsten carbide drills. The standard pointed drill bits create a hole with a conical-shaped bottom that leads to a geometric dead volume of 0.7 nL...

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Bibliographic Details
Published in:	Analytical chemistry (Washington) 1999-08, Vol.71 (15), p.3292-3296
Main Authors:	Bings, Nicolas H, Wang, Can, Skinner, Cameron D, Colyer, Christa L, Thibault, Pierre, Harrison, D. Jed
Format:	Article
Language:	eng
Subjects:	Analytical chemistry Chemistry Chromatographic methods and physical methods associated with chromatography Exact sciences and technology Fluids Instruments Other chromatographic methods
Online Access:	Get full text
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Summary:	Fused-silica capillaries have been connected to microfluidic devices for capillary electrophoresis by drilling into the edge of the device using 200-μm tungsten carbide drills. The standard pointed drill bits create a hole with a conical-shaped bottom that leads to a geometric dead volume of 0.7 nL at the junction, and significant band broadening when used with 0.2-nL sample plugs. The plate numbers obtained on the fused-silica capillary connected to the chip were about 16−25% of the predicted numbers. The conical area was removed with a flat-tipped drill bit and the band broadening was substantially eliminated (on average 98% of the predicted plate numbers were observed). All measurements were made while the device was operating with an electrospray from the end of the capillary. The effective dead volume of the flat-bottom connection is minimal and allows microfluidic devices to be connected to a wide variety of external detectors.
ISSN:	0003-2700 1520-6882