Table 2 Analytical methods and errors for the measurement of chemical components in the pore water
Component | Analytical method | Analytical error |
|---|---|---|
pH (25°C, 1 atm) | Potentiometry | 0.2% |
Alkalinity | Potentiometric titration | 1.2% |
NH4+ | Colorimetry | 7.5% |
Si | Colorimetry | 1% |
Cl- | Titration | 1% |
SO42− | Ion chromatography | 4% |
K | Atomic absorption spectrometry | 3% |
Na | ICP-AES | 7% |
Ca | ICP-AES | 4% |
Mg | ICP-AES | 1.2% |
B | ICP-AES | 3% |
Sr | ICP-AES | 3.5% |
Li | ICP-AES | 6% |
Ba | ICP-AES | 10% |
δ13CCH4 | Mass spectrometry | 0.3‰ |
δ13CC2H6 | Mass spectrometry | 0.3‰ |
δ13C∑CO2 | Mass spectrometry | 0.3‰ |
δ18OH2O | Mass spectrometry | 0.1‰ |
δDH2O | Mass spectrometry | 1‰ |