Spectrophotometric determination of Cu(II) with sequential injection analysis

A sequential injection system, based on the reaction of Cu(II) with diethyl dithiocarbamate (DDTC), was developed for the determination of Cu(II) in pl ant food and water samples. The extraction procedure, generally used to ext ract the Cu(II)-DDTC complex for subsequent analysis was eliminated in this procedure. The complex was detected spectrophotometrically in aqueous solu tions at 460 nm, The physical and chemical parameters depicting the system were studied to obtain optimum conditions for sample analysis. The system d eveloped is fully computerized and able to monitor Cu(II) in samples at sev en samples per hour with a relative standard deviation of <4.50% The calibr ation curve is linear from 0.5-5.0 mg/l with a detection limit of 0.2 mg/l. Interferences were reduced by introducing multiple flow reversals, to incr ease mixing between the reagent and sample zones, and subsequently enhance working of the masking agents (EDTA/citrate). (C) 1999 Elsevier Science B.V . All rights reserved.