[Zurück]

B. Lendl:
"Lasers, ultrasound and micro-chips: Enabling technologies for advanced chemical analysis using infrared spectrometry";
Vortrag: International Conference on Advanced Vibrational Spectrosopcy, ICVAS 5, Melbourne; 12.07.2009 - 17.07.2009; in: "Book of Abstracts of ICAVS 5", (2009).

Advances in technology for infrared spectrometry are of key importance in the development of innovative analysis systems for use in basic and applied
(bio)chemical research. These advances can include novel optical components such as light sources, detectors and fiber optics, but also supporting technologies for enabling new measurement concepts. These are needed to meet the increasing demands for reliable chemical information in our industrialized society. This presentation reports on three recent developments in (bio)chemical analysis systems which make use of such technological advances.

Using powerful mid-IR quantum cascade lasers, a portable analyzer for measuring oil-in-water has been developed. The new method is based on a liquid -liquid extraction step using cyclohexane followed by the determination of the extracted hydrocarbons in the cyclic extraction solvent by quantum cascade laser spectroscopy. This new method is a viable alternative to the former well established IR-method for oil in water, which used Freon 113 as the extraction solvent which, due to the ozone depleting potential of this CFC, has been banned and replaced by gas chromatography.

A standing MHz ultrasound field established between the plane ATR surface of a fiber optic probe and a piezo-ceramic element placed at a distance of a few millimeters can be used to manipulate particles in a suspension. Particles such as beads or microorganisms are captured in the nodes of the standing pressure waves. By controlling the frequency of the standing waves the particles can either be kept away from the ATR surface or pressed against it. In such a way a fiber optic in-line sensor system can be envisioned which is capable to discriminate between particles (micro-organism) and solutes (substrates and products) in a given suspension (fermentation).

Finally, using a micro-fluidic system made of an IR transparent material (CaF2 and Si) fast mixing of two solutions can be achieved with a minimum of reagent consumption. Such an enabling technology can be used for the time resolved study of (bio)chemical reactions including protein folding.