Determination of total sulfur compounds and benzothiazole in asphalt fume samples by gas chromatography with sulfur chemiluminescence detection.
Appl Occup Environ Hyg 2000 Sep; 15(9):695-704
As part of a collaborative project between the National Institute for Occupational Safety and Health and the Federal Highway Administration to evaluate asphalt pavers' exposures to asphalt fume and their potential health effects, a method was developed for the determination of total sulfur compounds and benzothiazole in asphalt fume samples. Asphalt fume samples were collected from asphalt mixtures with and without the addition of ground-up rubber tires.The asphalt fume samples were collected with sampling trains that consisted of a Teflon membrane filter and an XAD-2 adsorbent tube. Filter and sampling tube media were extracted with hexane and subsequently analyzed by gas chromatography with a sulfur chemiluminescence detector. Separation was achieved with a 100 percent dimethyl polysiloxane fused silica column. Typical calibration curves had linear correlation coefficients of 0.99 or better with a relative standard deviation (RSD) of 5 percent. Benzothiazole desorption efficiency (DE) determined using spiked sampling tubes ranged from 96.5 percent at 5.0 microg to 89.4 percent at 40 microg with RSD values from 0.9 to 4.0 percent. Benzothiazole storage recovery determined using sampling tubes spiked at 20 microg and refrigerated for 30 days at 4 +/- C was 89.8 percent when corrected for the DE with an RSD of 1.1 percent. The limit of detection for the method determined using spiked sampling tubes was 0.30 microg. Quantitation for total sulfur compounds and benzothiazole was against benzothiazole standards in hexane. Because of detector selectivity, sample preparation consisted of a simple hexane extraction even when samples had a high background due to hydrocarbon overload. Detector sensitivity provided quantitation in the sub-microgram benzothiazole was determined during the same analysis run, this method is straightforward and analytically efficient. The method has been used to analyze asphalt fume samples collected at several asphalt paving and roof operations.
Asphalt-industry; Asphalt-fumes; Work-environment; Worker-health; Workers; Health-hazards; Health-protection; Sulfur-compounds; Benzothiazoles; Gas-chromatography; Construction-materials; Construction-workers; Analytical-chemistry; Analytical-processes; Analytical-methods; Road-construction; Road-surfacing;
Author Keywords: Benzothiazole; Organic Sulfur-Containing Compounds; Gas Chromatography; Chemiluminescence; Asphalt Fume; Construction; Analytical Methods Development
Applied Occupational and Environmental Hygiene