Determination of volatile and semivolatile mutagens in air using solid adsorbents and supercritical fluid extraction

Abstract

Volatile toxicants may be present in emissions from mobile and stationary sources as well as in ambient air. Methods for collecting and concentrating volatiles from air samples have been developed. Solid-phase adsorbents were compared in their trapping efficiencies for dichloromethane (DCM), ethylene dibromide (EDB), 4-nitroblphenyl (4-NB), 2-nitrofluorene (2-NF), and fluoranthene (FI). Charcoal and Carbosieve were the most efficient media for retaining DCM, while XAD-4 was the best adsorbent for EDB and the aromatic compounds. Extraction of direct spikes of compounds from adsorbents using supercritical carbon dioxide resulted in greater than 90% recovery of EDB and 60-92% recovery of the aromatics. Integration of trapping and desorption methods with the Salmonella microsuspension bioassay was demonstrated with EDB and 4-NB recoveries from air; chemical analysis and bioassay gave comparable results (within 10%).

Direct determination of the phase distributions of semi-volatile polycyclic aromatic hydrocarbons using annular denuders

“…Problems with high PAH concentrations in the sorbent bed blanks compromised the data from several preliminary attempts at parallel sampling that are not reported here. Other workers have reported difficulty with internal standard recovery (Wong, et al, 1991), high blanks (Hunt and Pangaro, 1982) and storage-dependent blanks (Junk, et al, 1974) for XAD-4 resin beds.…”

Analytical Aspects of Amino, Quaternary Ammonium, Nitro, Nitroso and Related Functional Groups

“…XAD-4 was the best adsorbent for aromatic compounds, followed by supercritical fluid extraction (SFE) with carbon dioxide, resulting in 60 92% recoveries 490 . Synthetic hosts with improved binding affinities for nitro substituted PAHs guests were synthesized.…”

Future research needs associated with the assessment of potential human health risks from exposure to toxic ambient air pollutants

“…The chemical reactions of each VOC with nitrogen oxides in the atmosphere have different reaction mechanisms and rates. These reactions lead to the formation of ozone and the degradation of VOCs with the concurrent formation of a myriad of reaction products including mutagenic components (45,46,47).…”