Laboratory and field evaluation of a diffusive sampler for measuring halogenated anesthetic compounds

Abstract

Anesthetic gases such as desflurane, sevoflurane, isoflurane, enflurane, and halothane are used on a daily basis in operating theaters. Active sampling has historically been used to control the level of exposure to personnel. SKC 575-002 is a diffusive passive sampler filled with Anasorb 747. We validated this sampler in both laboratory and field experiments. Parameters tested were desorption efficiency, concentration, sampling time, relative humidity, and reverse diffusion, as well as storage stability for up to 8 weeks. Uptake rates were achieved by comparison with active sampling for each passive sampling trial of 1, 4, or 8 h. Analysis and detection were performed using gas chromatography with flame ionization detection (GC/FID). Multiple regression analysis was used to evaluate the influence of time, concentration, dose, and relative humidity. In the field evaluation experiments, intraclass correlation coefficients (ICC) were estimated. In the laboratory experiments, no problems were found with storage stability or reverse diffusion. The sampling rates for the five anesthetics vary, however, with exposure time and exposure level, with generally higher uptake rates at low concentrations and short sampling times. In the field experiments there was high agreement between the active and passive samplers for halothane, sevoflurane, and isoflurane (ICC > 0.83). When performing whole-day workplace measurements (TWA measurements) the SKC 575-002 can be recommended, and at levels around 1 ppm the following uptake rates should be used: enflurane and halothane, 12.3 mL min⁻¹; desflurane, 13.6 mL min⁻¹; isoflurane, 12.0 mL min⁻¹; and sevoflurane, 11.9 mL min⁻¹.