Microfluidic approach for studying CO _2 solubility in water and brine using confocal Raman spectroscopy

摘要

This Letter reports a fast and accurate method to quantify dissolved carbon dioxide in water and salted water (NaCl) using microfluidic systems probed by confocal Raman spectroscopy. The relationship of CO _2 solubility and Raman band intensity ratios (the ν _u of the CO _2 Fermi dyad over the water stretching band) can be fit from third order polynomial forms, depending on NaCl concentration. This approach allows for a much faster determination of CO _2 solubility measurements in pressurized aqueous media. More generally, by easily managing lithospheric fluids in microdevices, this strategy opens avenues towards true 'Geological Lab on chip'.