A comparison of three passive personal sampling methods for NO2

Abstract

Three personal passive sampling methods for NO2 were compared in a laboratory study. The methods include the Palmes tube, the Pro-Tek Colorimetric Air Monitoring System, and the Chronotox System. Samples were taken at 0.1, 1 and 2 times the 5 ppm OSHA standard for varying time spans of 0.25, 4 and 8 hours. The temperature, relative humidity and face velocity were held constant. The generation and exposure systems are presented along with the analytical results and a discussion of error. The Palmes tube successfully sampled at all levels except 0.5 ppm for 15 minutes. It had, however, an increasing standard deviation with increased loading. The Pro-Tek sampler successfully monitored all exposures falling within its linear working range. The Chronotox System sees 0.1×OSHA PEL the same as it sees zero concentration, but sampled accurately at loadings higher than 20.9 ppm hours.