Collect. Czech. Chem. Commun. 1988, 53, 749-755

Determination of trace quantities of freon by laser optoacoustic detection and classical infrared spectroscopy

Zdeněk Zelingera, Zlata Papouškováb, Marie Jakoubkováb and Pavel Engsta

a The J. Heyrovský Institute of Physical Chemistry and Electrochemistry, Czechoslovak Academy of Sciences, 182 23 Prague 8
b Institute of Chemical Process Fundamentals, Czechoslovak Academy of Sciences, 165 02 Prague 6-Suchdol


The sensitivity threshold was determined for a homebuilt apparatus with laser optoacoustic detection, enabling gases absorbing in the range of emission by the CO2 laser used to be detected selectively in trace concentrations. Gravimetrically calibrated homemade permeation tubes containing Freon 11 (CCl3F) were used, and a sensitivity threshold of 20 ppb was established. The dependence of the optoacoustic signal on the concentration of Freon 11 was measured in the dynamic mode; this concentration is given by the permeation standard type, carrier gas flow rate, and temperature. Classical IR spectroscopic measurements in the static mode were also performed.