# Detection limit of selective ion electrodes

I've been studying about the selective ion electrodes and I came across a question which I seem to not be able to answer. It has to do with why the detection limit for iodide ions is lower than the one for chloride ions.

I know that the detection limit depends on the type of the electrode, temperature, pH, the interfering ions etc., but how can I understand the difference between the detection limit of I- and Cl- ions?

• I'd suggest that the difference is indicated by difference in solubility products for the silver salts. The $K_{sp}$ for silver chloride is $1.77\times10^{−10}$, but for silver iodide the $K_{sp}$ is $8.52 \times10^{ −17}$. – MaxW Sep 9 '18 at 17:53