Applications CDTA (Cyclohexanediaminetetraacetic Acid Monohydrate). Description CDTA monohydrate also called as trans-1,2-Diaminocyclohexane-N,N,N',N'-tetraacetic acid monohydrate is an analytical reagent and a complexating agent for sodium. Definition "CDTA AR" typically stands for "Central Data Terminal Assembly, Automatic Routing," which is a component or system used for automated data routing and processing in various applications.