Water chemistry analysis
Water chemistry analyses are carried out to identify and quantify the chemical components and properties of a certain water. This include pH, major cations and anions, trace elements and isotopes. Water chemistry analysis is used extensively to determine the possible uses a water may have or to study the interaction it has with its environment. Water chemistry analysis is often the groundwork of studies of water quality, pollution, hydrology and geothermal waters.
Components commonly analyzed are pH, the cations Na, K, Ca, Mg, Si, the anions Cl, F, SO4, HCO3 the trace metals and metalloids Rb, Ti, Fe, Mn, etc., unstable volatiles such as CO2, H2S and O2, isotope ratios of 18O and 2H, organic material and nutrients.
Depending on the components, different methods are applied to determine the quantities or ratios of the components. While some methods can be performed with standard laboratory equipment, others require advanced devices, such as Inductively coupled plasma mass spectrometry (ICP-MS).
- Oxygen and H2S are most commonly measured by titration.
- Ion chromatography is a sensitive and stable technique that can measure Li, NH4, Na, K, Ca and Mg quantities among other components.
- For steam samples, gas chromatography can be used to determine methane, carbon dioxide, oxygen and nitrogen quantities.
- Spectrophotometry is most commonly used to measure iron content in water samples.
- Saturated calomel electrode and glass electrode are often used in conjunction to determine the pH of water.