Determination of elemental mercury by cavity ringdown spectrometry

Cold vapor cavity ringdown spectroscopy has been successfully applied to the detection of elemental mercury. Using an absorption cell 0.18 m in length, detection limits of 0.027 and 0.12 ng were obtained using peak area and peak height measurements, respectively. For the peak area measurement, this corresponds to a gas phase concentration of less than 25 ng m−3. For comparison, using a similar absorption cell, standard AAS yielded a Hg detection limit (peak height) of 9 ng, (gas phase concentration of ≡ 8.3 μg m−3).