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N. Kaun, M. Vellekoop, B. Lendl:
"Time-resolved Fourier transform infrared spectroscopy of chemical reactions in solution using a focal plane array detector";
Applied Spectroscopy, 60 (2006), 11; 1273 - 1278.

A Fourier transform IR (FT-IR) microscope equipped with a single as well as a 64 ´ 64 element focal plane array MCT detector was used to measure chem. reaction taking place in a microstructured flow cell designed for time-resolved FT-IR spectroscopy. The flow cell allows transmission measurements through aq. solns. and incorporates a microstructured mixing unit. This unit achieves lamination of the two input streams with a cross-section of 300 ´ 5 mm each, resulting in fast diffusion-controlled mixing of the two input streams. Microscopic measurement at defined positions along the outlet channel allows time-resolved information of the reaction taking place in the flow cell to be obtained. In this paper we show exptl. results on the model reaction between formaldehyde and sulfite. Using the single-point MCT detector, high-quality FT-IR spectra could be obtained from a spot size of 80 ´ 200 mm whereas the FPA detector allowed recording light from an area of 260 ´ 260 mm focused on its 64 ´ 64 detector elements. Therefore, more closely spaced features could be discerned at the expense of a significantly lower signal-to-noise (S/N) ratio per spectrum. Multivariate curve resoln.-alternating least squares was used to ext. concn. profiles of the reacting species along the outlet channel axis.