Highly sensitive successive determinations for PtII and SeIV ions have been developed based upon reactions with 1,4-dibromo-2,3-diaminonaphthalene (Br2DAN), which forms a near-infrared (NIR) absorbing complex (ε = 1.2 × 105 1 mol-1 cm-1 at 800 nm) and an emissive complex (ex. 386 nm, em. 604 nm) for PtII and SeIV ions, respectively, in acidic aqueous micellar solutions. In the presence of a cationic surfactant, cetyltrimethylammonium chloride, the detection limits for PtII and SeIV ions are 1.2 ng ml-1 (3σ) and 0.98 ng ml-1 (S/N = 3), respectively. Hydrobromic acid plays a key role to enhance the color development of the NIR-absorbing PtII complex. The influences of CuII and ZnII ions at the normal human serum levels are readily tolerated, and interference from FeI3II ion at 35 μmol 1-1 is circumvented by the addition of 50 μmol 1-1 of polyaminocarboxylates, such as EDTA.
ASJC Scopus subject areas
- Analytical Chemistry