Spectrophotometric determination of cadmium by the chromogenic reagent 2-pyridinediazoaminoazobenzene in the presence of triton X-100

A highly sensitive spectrophotometric method for determination of cadmium by the chromogenic reagent 2-pyridinediazoaminoazobenzene (Cadion Py) has been developed, In the presence of Triton X-100 and NH3-NH4Cl buffer solution, the optimum conditions for colour reaction of cadmium with Cadion Py, the molar absorptivity of which is 1.92 x 10(5) l mol(-1) cm(-1) at 530 nm, are studied, Elimination of interfering ions at ten-fold concentration is achieved by adding a mixed masking agent, Trace amounts of cadmium in water or waste water samples has been satisfactorily determined by the method.