National Institute for Occupational Safety and Health

“ Capacity of the 100-mg front sorbent section at breakthrough (effluent = 5% of test concentration) was approximately 5 μg of α-naphthylamine and 7.5 μg β-naphthylamine at 80% RH with a sampling range of 0.8 L/min in atmospheres containing approximately 80 μg/m 3 of the analytes. Breakthrough capacity was found to be strongly influenced by relative humidity, being reduced by 50% at 95% RH compared to the values found at 80% RH. In storage tests, quantitative recovery was obtained for 0.5-μg masses of α-naphthylamine on silica gel and filters if stored at -15 °C for up to seven days ”

“ Prepare graphs for filter and sorbent (DE vs. μg analytes recovered) . Analyze three quality control blind spikes and three analyst spikes to ensure that the calibration graphs and DE graphs are in control. ”

“ Sampler (Fig. 1) : high-efficiency glass fiber filter (Gelman Spectrograde or equivalent) , 13-mm diameter, followed by 100 mg and 50 mg beds of 20/45 mesh silica gel. Tubes are commercially available. NOTE: Some other glass fiber filters contained an impurity with the same GC retention time as α-naphthylamine [1] . 2. Personal sampling pump, 0.2 to 0.8 L/min, with flexible connecting tubing. 3. ”