出版社:National Institute of Occupational Safety and Health
摘要:Synthetic resin active carbon beads were applied to adsorption sampling of arsine in the air, and the accompanying analytical procedures including desorption of arsenic from the adsorbent and graphite furnace atomic absorption spectrophotometry to determine desorbed arsenic were studied. Results showed that active carbon produced from synthetic thermosetting resin beads was not contaminated with arsenic, an advantage over coconut-shell active carbon. The sampling tube, which was 4 mm in inside diameter and packed with 150 mg of the resin active carbon, was able to adsorb arsine at 0.5 ppm in 51 of dry air only with negligible breakthrough. The same tube previously humidified had a lower adsorption capacity: 0.5 ppm in 41 air. The adsorbed arsine on the resin active carbon was desorbed to 80%-94% with 2 ml or 10 ml of 0.01 M HNO3 solution with or without 10% ethyl alcohol under heat treatment at 75°C for 1 h. Arsenic desorbed into nitric acid solution was determined by atomic absorption spectrophotometry with pyrocoated graphite furnace and electrodeless discharge lamp, and the lower determination limit of arsenic in the final solution was 5 ng/ml (n =6, CV =0.12).