The polarographic measurement of halothane

The polarographic reduction of halothane on silver cathodes was studied. Silver catalyses the reduction of halothane: two electrons are exchanged in the reduction process. Experiments using a rotating disc electrode showed a linear relationship between observed current and halothane concentration. A Silastic membrane-covered polarographic electrode was constructed using a silver cathode which gave a good linear response to changes in halothane concentration over the range 0.5% v/v halothane in nitrogen. Oxygen interferes with the measurement of halothane, but can be removed from a gas sample before analysis.