Article pubs.acs.org/jced
Adsorption of Inhalation Anesthetics (Fluranes and Ethers) on Activated Carbons and Zeolites at Trace Level Concentrations Dirk Bucher,† Christoph Pasel,*,† Michael Luckas,† Jürgen Bentgens,∥ and Dieter Bathen†,‡ †
University of Duisburg-Essen, Lotharstraße 1, D-47057 Duisburg, Germany IUTA Institute of Energy and Environmental Technology, Bliersheimer Straße 58-60, 47055 Duisburg, Germany ∥ Klinikum Duisburg GmbH, Zu den Rehwiesen 9-11, 47055 Duisburg, Germany ‡
S Supporting Information *
ABSTRACT: This paper presents adsorption isotherms and desorption data of halogenated ethers (desflurane, isoflurane, and sevoflurane), which are used as inhalation anesthetics, and aliphatic ethers (diethyl ether and methyl propyl ether) from a nitrogen carrier gas stream. The isotherms were measured at 25 °C and 1 bar. Desorption was analyzed at temperatures between 25 and 250 °C. Zeolites with different structure and aluminum content as well as activated carbons with different pore size distributions were used as adsorbents. The analysis of the adsorption isotherms and the desorption data focuses on the interactions between adsorptive molecules and adsorbents’ surfaces. We discuss the specific influence of the molecular structure and polarity of the adsorptives as well as of the pore structure and surface chemistry of the adsorbents.
1. INTRODUCTION Clinical anesthesia uses the halogenated ethers desflurane, isoflurane, and sevoflurane as inhalation anesthetics.1 The global annual use of these fluranes exceeds several thousand tonnes.2−4 Besides their sedative effect these fluorinated hydrocarbons have a high global warming potential.2−7 During anesthesia, the anesthetics are vaporized and mixed with air, oxygen, or nitrous oxide. A mixture with flurane concentrations in the range of 0.5−6%v is delivered to the patient by an inhalation mask or by tube. The organism only metabolizes a minor amount of the inhaled fluranes (
