A hollow cathode lamp system for the determination of F, Cl, and Br in flowing gas streams is described. The lamp uses a relatively small cathode cavity diameter. The sample vapor in a He carrier is introduced at one end of the cathode cavity. Radiation is viewed at the other end. Relatively intense emission lines from F, Cl, Cl+, Br, and Br+ are observed when 100 ppm CClF3 and CBrF3, in He are introduced. The effects on the lamp emission characteristics of He pressure in the range of 15 to 40 Torr, with current in the range 10 to 100 mA, and the cathode cavity diameter in the range 0.8 to 3.2 mm are presented. Potential applications for GC detection are considered.
Lourdes Puig and Richard Sacks, "Hollow Cathode Plasma Emission Determination of F, Cl, and Br in Gas Streams," Appl. Spectrosc. 43, 801-810 (1989)