DETERMINATION OF CYANIDE AS TETRACYANONICKELATE(II) BY FLOW-INJECTIONAND SPECTROPHOTOMETRIC DETECTION

A two channel gas diffusion flow injection (GDFI) system was utilized successfully for the quantitative determination of cyanide. The analyt ical procedure is based on the complexation reaction in the acceptor s tream between nickel ions in ammoniacal solution and the cyanide ions formed as a result of the diffusion of hydrogen cyanide from the acidi fied donor stream where the sample is injected. The design and the che mical parameters of the GDFI system were optimized with respect to sen sitivity and sampling rate. The interference effect of a number of fre quently encountered chemical species on the analytical determination w as investigated in real samples and methods for their removal were dev eloped When applied to real samples where the cyanide ions are predomi nantly complexed with various metal ions the GDFI method was found to give results close to those obtained by standard distillation methods for weak acid dissociable (WAD) cyanide. (C) 1997 Elsevier Science B.V .