Validation of a diffusive sampler for NO2

Abstract

A diffusive sampler for NO2, Willems badge, was validated in laboratory experiments and field tests. The collecting reagent for NO2 in the sampler is triethanolamine, and the analysis is based on a modified colorimetric method, the Saltzman method. The analysis was performed by a flow injection analysis (FIA) technique. The sampling rate for the sampler was determined to be 40.0 ml min-1. There was no effect of NO2 concentration or relative humidity on sampling rate, and the influence of sampling time was found to be small. The detection limit was 4 micrograms m-3 for a 24 h sample. The capacity is high enough to allow sampling of 150 micrograms m-3 for 7 days, which is twice the recommended Swedish short-term (24 h) guideline value as a 98-percentile over 6 months. In field tests, the sampler performed well, even at wind speeds higher than 2 m s-1, and at low temperatures. The overall uncertainty of the method was 24%. The sensitivity and capacity of the method also make it suitable for personal sampling for 2-8 h in working environments.

The Use of Passive Diffusion Tubes for Measuring Concentrations of Nitrogen Dioxide in Air

“…Early studies showed no effect of RH on a short path sampler between 20 and 60% at room temperature (48). This was confirmed by subsequent studies with RH >20% at ambient temperatures (30,49). Studies with Palmes tubes between 5 and 85% RH at room temperatures (above 22 • C) showed a weak linear dependence of the sampling rate (expressed as changes in the diffusion coefficient) given by (50): This is equivalent to an 18% change in uptake rate between 20 and 80% RH.…”

Determinants of personal exposure to some carcinogenic substances and nitrogen dioxide among the general population in five Swedish cities

“…The uptake rate is 40 ml/min ( ± 22%). 10 After sampling, each filter was extracted with ultra-pure water, and nitrite ions were analyzed in a suppressed ion chromatography system with a conductivity detector. The detection limit for 7 days of measurements is 0.11 mg/m 3 .…”

Variability of personal chemical exposure in eight office buildings in Sweden

“…NO 2 was sampled with a Willems badge diffusive sampler impregnated with a solution of triethanolamine and acetone; the analyses were carried out in an FIA analyser with a spectrophotometric detector as described by Hagenbjo¨rk-Gustafsson et al (1999).…”