Abstract: | Nonlinear regression was applied to three empirical equations to model the response of a solid‐state lead ion‐selective electrode (ISE). One particular equation, previously reported to describe the response of a fluoride ISE, was found to also describe the response of a solid‐state lead ISE. Nonlinear regression was applied to the early portion of the response curve for the lead ISE and used to estimate the equilibrium potential for a range of test solutions. |