A new passive sampler for aldehydes.
Am Ind Hyg Assoc J 1999 Jul/Aug; 60(4):463-473
A new solid sorbent passive air sampler used a coated Tenax TA pellet that chemisorbed aldehydes by reaction with 10% (w/w) O-(2,3,4,5,6-pentafluorobenzyl) hydroxylamine hydrochloride. The aldehyde permeated a silicone membrane to gain access to the sampling element at the end of a cylinder of diffusion path length 1.1 cm and diameter 1.3 cm. Vapors of known concentrations around the threshold limit values/time-weighted averages of n-valeraldehyde and acrolein and specific relative humidities (RH) were generated by syringe pumps in a dynamic generation and dilution system. An exposure chamber allowed measurement of face velocities, temperatures, exposing vapor concentrations, and RH. The O-oxime derivative was desorbed quantitatively with hexane, and an aliquot injected for gas chromatographic analysis on a low polarity capillary column using mass spectrometric or electron capture detection. The critical face velocity of the sampler was 15-20 ft/min and the capacity was about 30 Ámoles. RH (3 -1% to 79 -2%) and temperature (4 -1 degrees C to 48 -2 degrees C) had no effects on the sampling constants of either aldehyde. Intermittent exposures had the same aldehyde equivalent recoveries as constant concentration exposures at the same time-weighted average. Stability after sampling was at least 6 months and the shelf life was over 3 months. The experimental sampling constants were 4.43 -0.19 cm3/min for valeraldehyde and 7.73 -0.57 cm3/min for acrolein.
Air-sampling; Air-sampling-techniques; Sampling-methods; Workplace-monitoring; Gas-chromatography; Aldehydes; Exposure-limits; Mass-spectrometry; Hexanes
Department of Environmental Health Sciences and UCLA Center for Occupational and Environmental Health, UCLA School of Public Health, 10833 Le Conte Avenue, Los Angeles, CA 90095-1772
5470-11-1; 110-54-3; 107-02-8
American Industrial Hygiene Association Journal
University of California Los Angeles, Los Angeles, CA