ORGANOSELENIDE AS A NOVEL IONOPHORE FOR A SILVER-SELECTIVE MEMBRANE-ELECTRODE

Three selenium-containing compounds, diphenyl selenide, benzyl phenyl selenide and dibenzyl selenide were used as neutral carriers to make a Ag+-selective membrane electrode. All three compounds exhibited highe r sensitivity to Ag+ than the corresponding sulfides and ethers. The h ighest sensitivity was obtained by dibenzyl selenide and an electrode constructed using this carries and bis(1-butylpentyl) adipate as a mem brane solvent in a poly(vinyl chloride) membrane matrix exhibited a ne ar-Nernstian response to Ag+ in the concentration range from 1 x 10(-5 ) to 1 x 10(-2) M with a slope of 52 mV per concentration decade. The lower limit of detection was around 1 mu M. The ion selectivity of thi s electrode for Ag+ was over 10(4) times that for other metal cations. Dibenzyl selenide and Ag+ interactions were examined by H-1-NMR spect roscopy.