RESUMEN
A new sampling method has been developed for the measurement of ethylene oxide (EtO) exposures in the workplace. This sampling method uses a hydrobromic acid-coated charcoal tube to collect EtO as its 2-bromoethanol reaction product. Because 2-bromoethanol is less volatile and less reactive than EtO, improved sampling capacity and sample stability are observed with this method over the collection of EtO on untreated charcoal. Sample analysis is performed by gas chromatography with electron capture detection (GC/ECD) following desorption with dimethylformamide (DMF) and derivatization of the 2-bromoethanol reaction product with heptafluorobutyrylimidazole (HFBI). The direct analysis of 2-bromoethanol by GC/ECD was not reproducible and this effect was attributed to the presence of excess hydrobromic acid (HBr) in the sample. This matrix effect was eliminated by the formation of the heptafluorobutyrate ester, a water-insoluble derivative of 2-bromoethanol, which was extracted into iso-octane for analysis. This analytical scheme is very sensitive and was used to monitor test atmospheres of EtO at the 0.1 ppm level. An average recovery of 96% was obtained for short-term samples (15 minutes) collected from a 5-ppm test atmosphere at 23 degrees C and 80% relative humidity. Similar high recoveries were obtained for 4-hr samples collected at a sampling rate of 0.1 L/min from test atmospheres in the concentration range of 0.1 to 16 ppm EtO at high humidity (80%) and ambient temperature (22 degrees C to 25 degrees C). Samples collected under these same conditions and stored for a minimum of 2 weeks resulted in average recoveries that ranged from 84% to 101%. Average recoveries of 97% were obtained for 2-ppm air samples collected at low humidity with no storage; however, storage of these samples at 22 degrees C to 25 degrees C resulted in an approximate loss of 5% per week. A field comparison study of samples, that was obtained from a hospital sterilization facility, used the test method and the Qazi-Ketchum sample method and resulted in a correlation for paired samples of 0.99 over a concentration range of 0.3 to 7.0 ppm EtO. These results indicate that this sampling and analytical method is a convenient, accurate and reliable means of monitoring EtO exposures in the workplace.
Asunto(s)
Ácidos , Contaminantes Ocupacionales del Aire/análisis , Óxido de Etileno/análisis , Adsorción , Contaminantes Ocupacionales del Aire/toxicidad , Carbón Orgánico , Cromatografía de Gases , Óxido de Etileno/toxicidad , Humedad , Ácido Bromhídrico , Indicadores y ReactivosRESUMEN
A sampling and analytical procedure for methyl-, dimethyl-, ethyl-, and diethylamine was developed in order to avoid problems typically encountered in the sampling and analysis of low molecular weight aliphatic amines. Samples are collected with adsorbent tubes containing Amberlite XAD-7 resin coated with the derivatizing reagent, NBD chloride (7-chloro-4-nitrobenzo-2-oxa-1,3-diazole). Analysis is performed by high performance liquid chromatography with the use of a fluorescence and/or UV/visible detector. All four amines can be monitored simultaneously, and neither collection nor storage is affected by humidity. Samples are stable at room temperature for at least two weeks. The methodology has been tested for each of the four amines at sample loadings equivalent to air concentration ranges of 0.5 to 30 ppm for a sample volume of 10 liters. The method shows promise for determining other airborne primary and secondary low molecular weight aliphatic amines.