Liberator cells are a common method of removing arsenic, antimony, and bismuth from copper electrorefining circuits. Reduction of arsenic involves a risk of toxic arsine gas formation, which must be mitigated by having appropriate conditions in the electrowinning cell. Laboratory-scale experiments are required to find these conditions and improve liberator cell function. The formation of arsine gas must be reliably detected. In this study, the suitability of the silver diethyldithiocarbamate (AgDDC) spectrophotometric method for arsine gas detection and quantification was studied. This study aimed to assess the suitability of the analysis method with the context and demands set by real hydrometallurgical experiments in mind.