Simultaneous collection of particles and gases followed by multielement analysis using nuclear techniques

Abstract

A simple system was constructed for the separation and collection of atmospheric particles and gases. The five-stage sampling train consists of a particle filter followed by four 7 LiOHimpregnated filters to collect acidic gases. The treated filters quantitatively collect acidic gas-phase species of B, S, CI, Br, I, As, Se, Sb and Hg. Simultaneous sampling with activated charcoalimpregnated and 7 LiOH-treated filters revealed that B, S, and As species were found only as acidic gases, while the others had both acidic and nonacidic contributions. Concentrations of up to 48 elements on the particle filters and nine elements on the treated filters were determined using instrumental neutron activation analysis and neutron capture prompt ~,-ray activation analysis. Minimum sampling volume estimates, average filter blank concentrations, and average atmospheric concentrations at College Park, MD and Wallops Island, VA are presented.

Volcanic gas emissions from Mount Erebus and their impact on the Antarctic environment

“…Forty-eight gas and aerosol samples were collected during December 1986December , 1988December , 1989, and January 1991 using custom-made 110 mm and Nuclepore 47 mm filter packs [Finnegan et al 1989;Kitto et al, 1988]. The packs consist of a particulate filter (one of the following filters were used: Fluoropore (1.0 tim), Zefluor (2.0 ttm), and Sartorius (1.2 ttm) teflon (PTFE) or Nuclepore polycarbonate aerosol (0.4 ttm)) followed by two or more impregnated filters.…”

Airborne Chernobyl Radioactivity in College Park, Maryland

“…Efficiency calibration was performed using a National Bureau of Standards, Standard Reference Material 4275 mixed radionuclide source. Previous experiments with activated charcoal [5] have shown that the acidic fraction, probably as HI, constitutes the majority (~70%) of the gaseous iodine. Organic iodide gases are not retained on the base-treated filters.…”

“…A complete description of the air sampling technique was described previously by Kitto et al [5]. In brief, 1 ambient air was drawn through an 11.0 cm 5-stage filter holder with a 1 μηι pore-size Fluoropore particlecollecting filter as the first stage.…”

Implementation of Differential Absorption LIDAR (DIAL) for Molecular Iodine Measurements Using Injection-Seeded Laser

“…To assess the dangerous characteristics of radioactive iodine, detailed knowledge of the behavior of iodine in the environment is required; the behavior is influenced by the concentration of water in the air and by atmospheric conditions. The background iodine concentration is at a level of a few nanograms per cubic meter, and a large amount of this atmospheric iodine exists as gaseous compounds like elementary iodine, hypoiodous acid, hydrogen iodide, and methyl iodide [10]. However, a distinct amount of atmospheric iodine also exists in a particulate iodine state [11], and the distribution of iodine species in aerosol particles is relatively unknown.…”