ADSORPTIVE DETERMINATION OF COPPER(II) IN SOLUTION AS ITS N,N-DIETHYLDITHIOCARBAMATE ON AN ELECTRODE-SEPARATED PIEZOELECTRIC QUARTZ-CRYSTAL

Copper(II) in solution reacts with N,N-diethyldithiocarbamate (DDTC) t o form a precipitate that adsorbs on the quartz plate in an electrode- separated piezoelectric quartz crystal (PQC) assembly. The frequency c hange was proportional to the concentration of copper(II) in the solut ion over the range 0.3-5.0 mu M. The adsorption depends on the pH, con centration of the buffer, standing time, concentration of DDTC, length of the mixing tube, and the flow rate of the solutions. Silver and me rcury(II) alone, among many metal ions in a 5 mM EDTA solution, interf ered because these metal ions reacted with DDTC to form adsorbing prec ipitates.