2024-03-29T05:25:10Z
https://nagoya.repo.nii.ac.jp/oai
oai:nagoya.repo.nii.ac.jp:00001417
2023-01-16T03:46:33Z
336:337:338:343
On the CO_2-bubbling extraction of dissolved He, Ne, H_2, Ar, N_2 and CH_4 in waters for their gas chromatographic determinations
Kawabe, Iwao
3291
Nagaoka, Yukiko
3292
Harada, Tomio
3293
Sawada, Atsushi
3294
Minagawa, Tetsuo
3295
1996-12
The CO_2-bubbling method for extracting gases dissolved in water samples has been reexamined in order to apply it to monitoring of dissolved gases in groundwaters. Dissolved He, Ne, Ar and N_2 in water equilibrated with the atmospheric air in a temperature range of 13-31℃ were extracted by the method, and gas chromatographically determined. The measured values for dissolved atmospheric He, Ne, Ar and N_2 show temperature variations in parallel with the calculated ones from their solubilities, but they are systematically higher than the calculated values by 18% for He, 11% for Ne, 6% for Ar and 8% for N_2. Although the CO_2-bubbling method is effective and convenient for extracting the dissolved gases in the field, appreciable amounts of blanks are associated with it. The blank sources of He, Ne, Ar and N_2 are the dissolved air in HCl and NaOH solutions used in the method and the direct air contamination. The extracted gas by the method contains H_2 and CH_4 from fluid inclusions of the marble dissolved in the extraction process to generate CO_2 for stripping. The blank H_2 and CH_4 depend on the nature of inclusions in the used marble and on the amount of the marble dissolved. We also found that the fine marble grains and particles formed by crushing and grinding retain significant amounts of tribochemically produced H_2. Such fine marble grains and particles should be removed completely from granular marble used in the extraction. When the CO_2-bubbling extraction is applied to routine analyses of dissolved gases in groundwaters, it is important to minimize such blank gases and to make reliable corrections for them.
国立情報学研究所で電子化したコンテンツを使用している。
departmental bulletin paper
Dept. of Earth and Planetary Sciences, Nagoya University
1996-12
The Journal of earth and planetary sciences, Nagoya University
43
1
16
http://hdl.handle.net/2237/2828
0919875X
eng