A method for the monitoring of the air-pollution in the operating room caused by anaesthesia agents

Volatile anaesthetic agents polluting the operating theatre atmosphere constitute a major chemical hazard source. A gas chromatographic method using a frequency modulated ECD and a mass spectrometer (1-200 AMU) have been used for the determination of nitrous oxide, halothan and isofluoran traces in operating theatre atmosphere. The sampling devices includes a small movable rotary pump, which inflates nylon bags, 60 ml grease-free syringes and balloons. Since no standards are commercially available, a static calibration method employing a 25 l gas extricator into which liquid halothane or isofluorane is introduced, by using a micropippete and isothermally vaporised and a dynamic method employing N₂O, N₂, O₂ gas cylinders equipped with flow-meters allowing the formation of variable partial pressure mixtures have been developed. The sensitivity of the method is ≈1 ppm (v/v) for halothane and isofluorane and ≈10 ppm (v/v) for nitrous oxide