Methods development for sampling and analysis of chlorine, chlorine dioxide, bromine, and iodine. research report for chlorine.
An attempt to develop a personal air sampling and analysis method for determining chlorine (7782505) in workplace air was described. Twenty seven solid sorbents were screened for their ability to react specifically with chlorine vapor in a gas/solid reaction. Testing methods for the various sorbents included the use of gas chromatography, high pressure liquid chromatography (HPLC), spectrophotometry, and iodometry. Diphenylamine on Fluoropak 80, N- vinylcarbazole on Fluoropak 80, m-aminophenol on Fluoropak 80, and sodium-sulfamate and sodium-hydroxide on silica gel displayed a significant degree of reactivity; however, none of the substrates provided an entirely suitable collection medium. The reaction of chlorine with diphenylamine produced a green color that faded within a few hours. Upon exposure to dry air, N-vinylcarbazole produced an unidentified product that reacted with the methanol extraction solvent to produce a compound that could be separated from other reactants and N-vinylcarbazole by HPLC. The area of the peak attributed to the compound was found to be proportional to the quantity of chlorine sampled into the N-vinylcarbazole sorbent tubes. The reaction product was not observed when chlorine was sampled from humidified air. The compound m-aminophenol demonstrated a great affinity for chlorine, but the reaction product was not identifiable. The sodium-sulfamate and sodium-hydroxide sorbents offered adequate capacity for chlorine. Because of their low affinity for chlorine-dioxide (10049044) the sorbents provided a means of detecting chlorine in the presence of chlorine-dioxide. However, the presence of water affected the determination of chloramine produced by reaction of chlorine and the sulfamate ion. The authors conclude that methods based on the sorbents studied are not worthy of validation. If solid sorbents cannot be found, then the adaptation of liquid reactive systems to passive dosimetry may offer better potential than do solid substrates in developing a suitable sampling and analytical method for chlorine.
NIOSH, U.S. Department of Health and Human Services, Cincinnati, Ohio