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Zeitschriftenartikel:

M. Kölhed, P Hinsmann, J. Frank, P. Svasek:
"On-line Fourier Transform Infrared Detection in Capillary Electrophoresis ";
Analytical Chemistry, 74 (2002), 15; S. 3843 - 3848.



Kurzfassung englisch:
The coupling of Fourier transform IR (FT-IR) spectroscopy as a new online detection principle in capillary electrophoresis (CE) is presented. To overcome the problem of total IR absorption by the fused-silica capillaries that are normally employed in CE sepns., a micromachined IR-transparent flow cell was constructed. The cell consists of two IR-transparent CaF2 plates sepd. by a polymer coating and a titanium layer producing an IR detection window, 150 mm wide and 2 mm long, with a path length of 15 mm. The IR beam was focused on the detection window using an off-axis parabolic mirror in an optical device (made inhouse) attached to an external optical port of the spectrometer. The connections between the fused-silica capillaries and the flow cell were made by a small O-ring of UV-curing epoxy adhesive on the sharply cut ends of the capillaries, allowing the capillaries to be easily replaced. Aq. solns. comprising mixts. of adenosine, guanosine, and adenosine monophosphate were used to test the system's performance. Conventional online UV detection was employed to obtain ref. measurements of analytes after the IR detection flow cell. The limit of FT-IR detection for all analytes (in abs. amts.) was in the nano- to picogram range corresponding to concns. in the low-millimolar range

Erstellt aus der Publikationsdatenbank der Technischen Universität Wien.