Optimization of a passive sampling method for determination of airborne naphthalene for residential indoor air monitoring

Several exposure studies of indoor air contaminants have used passive sampling devices (PSDs) to determine VOC levels. An existing passive method to determine airborne naphthalene at low levels offers reproducible but low recoveries, considered unacceptable for producing quantitative results. Given the need to determine airborne naphthalene quantitatively with high sensitivity and high quality, optimization of the passive sampling method was undertaken. Seven solvent combinations were evaluated to determine the extraction efficiency, toluene being the most promising. Detailed assessments of toluene extracts allowed optimization of chromatographic performance and characterization of the new method. Passive sampling was then conducted as part of an indoor air exposure study in up to 6 locations within residences including the living room, garage, basement, bathroom, main bedroom and kitchen for both 7-day and 24-hr integrated samples. Results indicate summer naphthalene concentrations were highest in the garage, followed by the basement and then living room.