Microfluidic Devices Connected to Fused-Silica Capillaries with Minimal Dead Volume
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- 作者：Nicolas H. Bings ; Can Wang ; Cameron D. Skinner ; Christa L. Colyer ; Pierre Thibault ; and D. Jed Harrison
- 刊名：Analytical Chemistry
- 出版年：1999
- 出版时间：August 1, 1999
- 年：1999
- 卷：71
- 期：15
- 页码：3292 - 3296
- 全文大小：65K
- 年卷期：v.71,no.15(August 1, 1999)
- ISSN：1520-6882
文摘
Fused-silica capillaries have been connected to microfluidic devices for capillary electrophoresis by drilling intothe edge of the device using 200-
m tungsten carbidedrills. The standard pointed drill bits create a hole with aconical-shaped bottom that leads to a geometric deadvolume of 0.7 nL at the junction, and significant bandbroadening when used with 0.2-nL sample plugs. Theplate numbers obtained on the fused-silica capillaryconnected 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 substantiallyeliminated (on average 98% of the predicted plate numbers were observed). All measurements were made whilethe device was operating with an electrospray from theend of the capillary. The effective dead volume of the flat-bottom connection is minimal and allows microfluidicdevices to be connected to a wide variety of externaldetectors.
m tungsten carbidedrills. The standard pointed drill bits create a hole with aconical-shaped bottom that leads to a geometric deadvolume of 0.7 nL at the junction, and significant bandbroadening when used with 0.2-nL sample plugs. Theplate numbers obtained on the fused-silica capillaryconnected 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 substantiallyeliminated (on average 98% of the predicted plate numbers were observed). All measurements were made whilethe device was operating with an electrospray from theend of the capillary. The effective dead volume of the flat-bottom connection is minimal and allows microfluidicdevices to be connected to a wide variety of externaldetectors.