One of the promising electrochemical carbon capture systems relies on quinone chemistry. Quinones are organic molecules containing an unsaturated six-member ring with two carbonyl groups. They exhibit two potential mechanisms of CO2 capture. Firstly, the nucleophilicity-swing mechanism occurs in aprotic solvents during electrochemical redox reactions. The phenolate groups upon quinone reduction reversibly react with carbon dioxide via nucleophilic addition, which results in the formation of quinone-CO2 adducts. Secondly, the pH-swing mechanism occurs in protic solvents. Depending on the pKa of the hydroquinones and the local pH, the electrochemical reduction of quinones can be proton-coupled and creating hydroxide ions, which capture CO2 as carbonate or bicarbonate. The majority of the quinones reported in literature for CO2 capture applications have been dissolved in aprotic solvents or immobilized on the electrodes , demonstrating a nucleophilicity-swing mechanism. One exception is our recent report on the first aqueous quinone flow chemistry-enabled electrochemical CO2 capture process, which was based on bis propyl]-anthraquinones (BTMAPAQs) . Such aqueous systems are highly attractive due to the safety and cost-effectiveness they offer by utilizing water, which is non-flammable and cheap. Additionally, aqueous electrolytes feature high ionic conductivity. This prior work demonstrated that, given the aqueous nature of the system, both pH-swing and nucleophilicity-swing mechanisms contribute to CO2 capture across a range of operational conditions. However, traditional methods of measuring the total amount of CO2 captured or released only allow for reporting the combined contribution of these two mechanisms.