Laser atomic absorption spectrometry of excited Hg in a discharge applyingsum frequency mixing of two diode lasers (preliminary results)

Wavelength modulation diode laser atomic absorption spectrometry is applied to the detection of atomic mercury. Transitions from metastable energy lev els highly populated in a radio-frequency discharge are induced with laser diodes by use of nonlinear techniques. The wavelength of one strong transit ion at 365.119 nm with a high oscillator strength is obtained by sum freque ncy generation of two diode lasers. The cold vapor technique is used to tra nsfer ionic into atomic mercury. The mercury in the vapor phase is transpor ted by an argon stream into the discharge tube. From the time-dependent abs orption signals detection limits of 100 ng/L are achieved at this state of research.