Comparison of recoveries of trichloroethylene from charcoal tubes and thermally-desorbable personal monitors

Solvent-extractable NIOSH charcoal tubes and thermally-desorbable Simtec Adsorba porous polymer monitors for trichloroethylene are compared for recovery efficiencies. The latter monitors are shown to have better recovery efficiencies with less variability than the charcoal monitors. Methods of distribution-free statistical evaluation are outlined for comparing monitors so that reliable conclusions can be drawn.     

The gas chromatographic separation of anaesthetic agents and aerosol propellants in operating room air using serially packed columns

The use of gas chromatographic columns serially packed with molecular sieve 5A and Porapak-Q (both with particle sizes in the range 50–80 mesh) is described for the analysis of operating theatre air for nitrous oxide, halothane, trichloroethylene, enflurane, Freon-11 and Freon-12. Various combinations of lengths of the two packings were evaluated; the most suitable was 2.75 m of Porapak-Q and 0.29 m of molecular sieve 5A with a column temperature of 250°C. With the electron capture detector used, the optimum temperature to give high sensitivity for nitrous oxide was 350°C.