Determination of fluorine, chlorine, bromine and iodine by a barrier discharge radiofrequency helium plasma

An barrier discharge radiofrequency helium glow -dischage plasma for the de termination of fluorine, chlorine, bromine and iodine with atomic-emission spectroscopy was developed. A glass tube wrapped with two copper film elect rodes, one of which was earthed and the other supplied with a radiofrequenc y impulse high voltage (98 kHz, 3.2 kV), maintained a glow discharge with a stream of helium gas. The emission was monitored by; a spectrometer using a charge-coupled device (CCD) in the range of 730 similar to 960 nm. The em ission lines of fluorine(793.2, 739.9 nm), chlorine (833.3, 837.6, 858.6, 8 94.8, 912.1 nm etc.), bromine (827.2, 882.5, 889.8, 926.5 nm etc.) and iodi ne (905.8 nm)were determined. A linear calibration of 1 similar to 10 mug f or fluorine, and chlorine. and 0.1 similar to 1 mug for bromine were achiev ed. The emission intensity was stronger in the order of bromine > iodine > chlorine > fluorine.