A new passive sampler for regulated workplace aldehydes

A new solid sorbent passive air sampler for aldehydes had a silicone membrane atop a cylindrical diffusion path of 1.1 cm length and 1.3 cm diameter above a 10 percent (w/w) O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine hydrochloride (PFBHA) Tenax TA pellet. Known vapor concentrations of Occupational Safety and Health Administration (OSHA)-regulated aldehydes near their permissible exposure limits were generated from a syringe pump dynamic air dilution system that was connected to an exposure chamber. The O-oxime derivatives from aldehyde reaction with PFBHA were desorbed with hexane, and quantified by capillary gas chromatography/mass spectrometry (GC/MS) or gas chromatography/electron capture detection (GC/ECD). The capacity for aldehydes with one carbonyl group was 30-35 mumoles, and 15 mumoles for the dialdehyde, glutaraldehyde. The experimental sampling rates in mL/min were 8.86 +/- 0.38, acetaldehyde; 11.69 +/- 0.32, chloroacetaldehyde; 7.85 +/- 0.19, crotonaldehyde; 9.97 +/- 0.10, formaldehyde; 6.47 +/- 0.42, furfural; and 4.46 +/- 0.15, glutaraldehyde. Other data on valeraldehyde and acrolein have shown that the sampling constants were independent of face velocity between 0.1 to 0.35 m/s (20 to 70 fpm), temperatures between 9 to 48 degrees C, RH between 3 to 79 percent, and intermittent sampling exposure pattern.