Cyclic polyamine ionophore for use in a dibasic phosphate-selective electrode.
A cyclic polyamine, 3-decyl-1,5,8-triazacyclodecane-2,4-dione (N3-cyclic amine), was used as the ionophore for a dibasic phosphate-selective electrode. This electrode exhibited a linear response between 1.0 mumol/L and 0.1 mol/L dibasic phosphate activity with a near-Nernstian slope of approximately -29 mV per activity decade. The electrode selectivity for dibasic phosphate over other commonly occurring anions was evaluated. A mechanism for the selectivity of the electrode toward HOP4(2-) ions is postulated to be a function of the size and charge of the N3-cyclic amine ionophore relative to the size and charge of HPO4(2-) ions. The electrode's superior selectivity and sensitivity make possible the direct measurement of phosphate activity in a wide variety of applications.
Carey
C M
CM
American Dental Association Health Foundation, Paffenbarger Research Center, National Institute of Standards and Technology, Gaithersburg, Maryland 20899.
Riggan
W B
WB
D006571:Heterocyclic Compounds / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D017736:Ion-Selective Electrodes / Q000592:standards*; D007476:Ionophores / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D010710:Phosphates / Q000737:chemistry*; D011073:Polyamines / Q000737:chemistry*; D012015:Reference Standards; D013056:Spectrophotometry, Ultraviolet
C091054:3-decyl-1,5,8-triazacyclodecane-2,4-dione; D006571:Heterocyclic Compounds; D007476:Ionophores; D010710:Phosphates; D011073:Polyamines