Non-flame atomic absorption in the vacuum ultraviolet region. The direct determination of mercury in air at the 184.9-nm resonance line

Mercury in the atmosphere was analyzed continuously without prior scrubbing or sample collection. The mercury resonance line at 184.9 nm was utilized. This was made possible with an r.f. carbon rod atomizer and by pumping the monochromator with argon : the sensitivity was 0.1 μg Hg m^-3. The method was sensitive to the type of mercury light source used. Strong reversal of the resonance lines on commercial hollow cathodes was indicated. Some anomalous temperature affects were observed.