Simultaneous trace analysis of nitrous oxide and halothane in air.

A gas chromatographic method for the simultaneous analysis of halothane and nitrous oxide in operating theatre atmospheres has been developed and evaluated. The flame ionization detector is suitable for the quantitative analysis of halothane in concentrations approaching one part per million. The frequency-modulated electron capture detector is highly sensitive to nitrous oxide but we have found it to be non-linear over the range 25--1000 p.p.m. The overall reproducibility of the gas chromatographic method based on the dynamic technique of standard preparation is approximately 4%. Effective exposure of personnel to pollutant anaesthetics is assessed by the analysis of end-expired gas.