Electrode response and detection limits of a fluoride-selective electrode in anionic buffer solutions

It was found that electrode response and the chemical nature of the background activity appearance of a fluoride-selective electrode are identical in nonbuffered solutions and anionic complexing media. The background activity was assessed in dipotassium hydrogen citrate solutions of different concentrations. At zero ionic strength, the background activity was constant and equal to alpha(1 = 0) = (4.0 +/- 0.4) x 10(-6) M at 25.0 +/- 0.1degreesC. Detection limits were calculated for different confidence levels. It was shown that a variation in the nature and concentration of masking, ligands cannot cause a change in performance characteristics of the electrode and of the method.