Determination of Methyl Bromide in Air Resulting from Pest Control Fumigations
1996; American Chemical Society; Linguagem: Inglês
10.1021/bk-1997-0652.ch015
ISSN1947-5918
AutoresJames E. Woodrow, Puttanna S. Honaganahalli, James N. Seiber,
Tópico(s)Pesticide Exposure and Toxicity
ResumoA method for measuring residues of methyl bromide in air entails concentrating the fumigant on charcoal from an air-stream at a flow rate of ≤100 mL/min, desorbing the trapped material with benzyl alcohol solvent in a sealed vial at 60-110°C for 10-15 min, and then sampling the equilibrated vapor for gas chromatographic assay using electroncapture detection. The desorbed vapor is chromatographed on a 27 m x 0.32 mm (id) porous-layer open tubular column, on which methyl bromide has a retention time of about 6 min at 90°C and at a carrier gas flow rate of about 3.5 mL/min. Using this method, standard curves were linear over at least three orders of magnitude and a practical limit of detection for field air was less than 20 ng/m3 (<5 ppt). Because of the possibility of methyl bromide hydrolysis on charcoal and uneven (or inconsistent) data precision using charcoal air sampling, we discuss the use of a polymeric adsorbent for air sampling and compare it with charcoal in terms of methyl bromide trapping, stability, and data precision.
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