Gas chromatographic separation of anaesthetizing gaseous mixtures

Summary

The composition of inhaled and exhaled gaseous mixtures in a half-opened system of anesthesia has been determined. Gas chromatography has been used and a gas chromatograph with dual column system has been developed for this purpose.

The analyses were carried out at a room temperature on packed columns.

A dual column system suitable for determining uneasily separable gaseous mixtures was published byMurakami [1] who applied this system to the separation of Ne, O₂, N₂, CO₂. In further papers [2, 3, 4, 5] the dual column equipment was used for the analysis of Ne, O₂, N₂, CO₂, C₂H₂, N₂O with suitable packing materials. The determination of the concentration of all these components was carried out for pulmonary function testing [6, 7, 8]. The same equipment was used for the determination of O₂, N₂, CO₂ concentrations in human blood [9, 10, 11, 12, 13].

The analysis of N₂O was first published byJanák andRusek [14] and the separation of N₂O on Porapak was carried out in 1966 [15]. The application of gas chromatography for the determination of the inhalation anesthetic Halothane (2-bromo-2chloro-1, 1, 1-trifluoroethane) has been described byVandam [16]. In further papers dealing with this problem the causes of formation of impurities were investigated [17, 18, 19].

The present paper deals with the chromatographic determination of Halothane, O₂, CO₂, N₂O. The working conditions and the scope of the experiment were chosen in order to get information on the composition of the inhaled as well as exhaled gaseous mixture from the anesthetic system.

The working conditions determined from the results of analyses of tank mixtures carried out in the laboratory [20] did not appear suitable for analyses of real mixtures when the samples were taken directly from the anestetic system.