Commercial Chlorine Research Articles

ESTIMATION OF IMPURITIES IN LIQUID CHLORINE BY INFRARED ABSORPTION SPECTROPHOTOMETRY

Commercial chlorine may contain small amounts of chlorinated organic impurities, some of which have been estimated by infrared absorption spectrophotometry. Liquid chlorine has no infrared absorption spectrum up to 1180 cm−1. This has enabled long path lengths to be used to increase the sensitivity to low concentrations of organic compounds. A 5 cm. tantalum-clad steel pressure cell fitted with calcium fluoride windows was used, and spectra were recorded on a single beam instrument fitted with a calcium fluoride prism. Using extinction coefficients, estimations were made to a few parts per million on impurities such as chloroform, methylene chloride, phosgene, and hexachlorobenzene. The method was checked by known additions to pure liquid chlorine. The estimation of moisture in liquid chlorine is discussed.