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Validation of a passive sampler for aldehydes.
Tsai-SW; Que Hee-S
American Industrial Hygiene Conference and Exposition, May 9-15, 1998, Atlanta, Georgia. Fairfax, VA: American Industrial Hygiene Association, 1998 May; :46-47
O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine hydrochloride (PFBHA) has been used to analyze aldehydes in water because of its fast quantitative reaction to form oximes suitable for detection at the picogram (pg) level by gas chromatography /mass spectrometry (GC/MS) and gas chromatography/electron capture detection (GC/ECO). The PFBHA method also has been used to chemisorb aldehydes from air samples by dynamic sampling. The present aim was to validate a new aldehyde passive sampler for personal sampling in the environmental/ industrial hygiene field. Valeraldehyde, acrolein, formaldehyde, acetaldehyde, glutaraldehyde, chloroacetaldehyde, crotonaldehyde, and furfural were tested. Effects of different temperatures, relative humidities (RH), and face velocities were evaluated. Sampling capacity, shelf life, and storage stability were also determined. A 13 mm diameter and 0.2-cm thick pellet of PFBHA coated Tenax GC (10'%, w /w) was made by a hand press. The sampler has a silicone membrane and a diffusion path length of 1.1 cm. The sampling contrast was determined by exposures at known face velocities (20 to 70 ft/min) at known vapor concentrations about the PEL generated by a syringe pump into pure air of known flow rate, and diluted appropriately before the exposure chamber. The ppm-hour levels were equivalent to 0, 0.25, 0.5, 1, 1.5, and 2 times the PEL for 8 hours. The PFBHA-aldehyde oximes were desorbed by hexane and determined by selected ion monitoring GC/ MS at m/z 181. The desorption efficiencies for direct aldehyde spiking were 94.0 +/- 3.6%, valeraldehyde; 98.5 +/- 7.3%, acrolein; 99.9 +/- 9.8%, formaldehyde; 96.3 +/- 3.2%, acetaldehyde; 100.9 +/- 1.7%, glutaraldehyde; 112.7 +/- 4.6%, chloroacetaldehyde; 101.3 +/- 7.9%, crotonaldehyde; and 89.3 +/- 3.4%, furfural. The shelf life of the sampler was longer than 6 months and the sample stability was longer than 6 weeks with no difference between room temperature and 41C storage. The capacity was 30·35 mmoles for total aldehydes collected. The dialdehyde glutaraldehyde showed a capacity of 15 mmole. There were no significant effects from different RHs (3 +/- 1 degree/(1,36 +/- 2%, and 79 +/- 2%), exposure temperatures (9 +/- nc, 25 +/- 21C, and 48 +/- 21C), and intermittent sampling. The experimental sampling rates were in mL/ min: 4.43 +/- 0.19, valderaldehyde; 7.73 +/- 0.57, acrolein; 9.970 +/- 0.055, formaldehyde; 8.68 +/- 0.58, acetaldehyde; 4.46 +/- 0.15, glutaraldehyde; 11.48 +/- 0.26, chloroacetaldehyde; 7.85 +/- 0.19, crotonaldehyde; and 6.47 +/- 0.42, furfural. The mass collected was independent of face velocity between 20 to 70 ft/min.
Airborne-particles; Air-monitoring; Air-quality-measurement; Air-sampling; Air-sampling-techniques; Chemical-hypersensitivity; Chemical-reactions; Exposure-assessment; Gas-chromatography; Laboratory-techniques; Laboratory-testing; Mathematical-models; Quantitative-analysis; Sampling-methods; Standards; Vapor-detectors; Vapor-volume; Water-analysis; Water-sampling
Research Tools and Approaches: Exposure Assessment Methods
American Industrial Hygiene Conference and Exposition, May 9-15, 1998, Atlanta, Georgia
University of California Los Angeles, Los Angeles, CA