takata_etal_2002b.html
Bulletin of Glaciological Research 19 (2002) 107-112
©Japanese Society of Snow and Ice
Application of laser induced breakdown spectroscopy for determination of sodium in ice
Morimasa
TAKATA1*, Kumiko
GOTO-AZUMA2*,
Yoshiro ITO1,
Nobuhiko AZUMA1 and
Hisako KANDA2**
1 Nagaoka
University of Technology, Nagaoka, Niigata 940-2188 Japan
2 Nagaoka Institute of Snow and Ice Studies, Nagaoka, Niigata 940-0821
Japan
(* Present address: National Institute of Polar Research, 1-9-10
Kaga, Itabashi-ku, Tokyo 173-8515 Japan)
(** Present address: Nagaoka University of Technology, Nagaoka,
Niigata 940-2188 Japan)
Abstract
We have developed a continuous and non-destructive technique to analyze chemical constituents in ice that uses laser-induced breakdown spectroscopy (LIBS). In an earlier paper, we showed that this method can determine the calcium concentrations in ice. In this paper, we apply the same technique to determine sodium concentrations in ice. First, we quenched sprayed thin layers of standard sodium solutions in succession to build up thick ice samples containing known concentrations of Na. Then, the emission of Na around a wavelength of 589 nm was measured when the ice samples were irradiated with focused laser pulses. The volume of ice consumed for each measurement was only about 1 mm in both diameter and depth. Under nearly optimal conditions, the emission intensity was proportional to sodium concentration when the latter were 10 - 200 µg g-1. We also found a linear relationship in the high concentration range (10 - 1000 µg g-1). The detection limit was estimated to be 17 µg g-1. These results indicate that LIBS can be used to analyze sodium in sea ice, although a much lower detection limit is needed to analyze ice cores.