Associate research officer, Unsteady Aerodynamics Laboratory, National Aeronautical Establishment, National Research Council of Canada, Ottawa, Ont.
Pages: 12 Published: Jan 1982
An analytical technique is described for simultaneous determination of fenitrothion and tris(2-ethylhexyl)phosphate (TEHP) in air. Total airborne (vapor and aerosol) fenitrothion and TEHP were collected in glass tubes 75 by 6.3 mm outside diameter containing a 10-mm plug of Tenax GC. Air was drawn through the adsorber at a rate of about 1 L/min for a period of up to 4 h to measure the dosage of fenitrothion and TEHP or for 2 to 3 min to determine timewise variations of concentration. The break-through volume of the adsorbers was larger than 360 L at a sampling rate of 1 L/min. The material collected on Tenax GC was thermally released directly into a gas chromatographic column and analyzed using a thermionic detector. Cascade impactors were used to collect aerosol and measure the drop-size distribution over a range of 1 to 30 μm. The concentrations of fenitrothion and TEHP measured in field experiments varied over a range of 3 × 10−12 g/L to 2 × 10−8 g/L and 5 × 10−12 g/L to 2 × 10−10 g/L, respectively. The precision of the method was better than ± 10 percent using different adsorbers and ± 5 percent for the same adsorber. Field tests were conducted in New Brunswick forests during the 1980 spruce budworm control program.
fenitrothion, tris(2-ethylhexyl)phosphate, vapor, aerosol, sampling, thermal desorption, chromatographic analysis, drop-size distribution, monitoring, toxic materials
Paper ID: STP33985S