The sources of CO2 for industrial purposes are diverse. They range from chemical processes such as hydrogen production or ammonia synthesis to fermentation processes and natural sources. Therefore, the composition of the feed gas varies significantly in terms of potential impurities that need to be removed. In order to apply appropriate purification steps in suitable quantities, analysis of the raw CO2gas is of utmost importance. Specifically, natural sources of CO2 can exhibit significant fluctuations in their impurity profile, potentially resulting in a lower quality product over time, as the plant's purification system may not be capable of handling increased levels of contaminants. To respond quickly to these fluctuating compositions of the raw gas in the process, on-line analysis of the raw gas is needed.