PLASMA PREEXCITATION OF GASEOUS SAMPLES FOR LASER-INDUCED FLUORESCENCE SPECTROMETRIC ANALYSIS

Analysis of gases by a laser-induced fluorescence spectrometric method was investigated for the determination of trace impurities. Low detection limits for oxides of nitrogen were obtained, 0.5 p.p.b. for NO2 and 1 p.p.b. for NO. The fluorescence of neon excited from a metastable state was recorded as a pulsed discharge for the determination of Ne in He and Ar, with detection limits of 0.3 p.p.b. and less than 100 p.p.m., respectively. The detection limits for nitrogen in rare gases was determined to be 1 p.p.b. by oxidation of N2 to NO2 and 10 p.p.b. using excitation of nitrogen fluorescence in a pulsed discharge.