An atmospheric pressure argon glow discharge is shown
to detect trace levels of carbohydrates in aqueous flowing
systems, using either of two glow discharge solution
interface configurations. The first configuration consists
of an oscillating glow discharge sustained between a flowing
aqueous cathode and platinum anode. Picomole and micromolar
mass and concentration detection limits, respectively, are
obtained for sucrose in an aqueous flow injection system
when monitoring discharge oscillation frequency or discharge
current. The second configuration consists of a non-oscillating
glow discharge sustained between metallic
electrodes near the flowing output of a high performance
liquid chromatography system. A conductivity detector
detects the acidic product formed when each carbohydrate
elutes and is exposed to the glow discharge. This detector
yields femtomole and nanomolar mass and concentration
detection limits, respectively, for a variety of
carbohydrates and competes with the best of the commercially
available liquid chromatography carbohydrate detectors. An
increase in the discharge electrode spacing or reduction in
the liquid flow rate increases detector sensitivity, since
the discharge area and solution exposure time are increased,
respectively. The aqueous carbohydrate products formed from
exposure to the glow discharge are similar to those formed
from exposure to high energy radiation. Acid, hydrogen
peroxide, and an absorbing species all form in amounts
proportional to carbohydrate concentration and glow
discharge exposure time, with yields approximating those
encountered when using high energy radiation. / Graduation date: 1997
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/34373 |
| Date | 30 September 1996 |
| Creators | Herring, Christopher Jackson |
| Contributors | Piepmeier, Edward H. |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
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