Abstract: A water repellent coating composition includes fine particles having functional groups on their surfaces and having a particle diameter ranging from 10 nm to 1 mm; a coupling agent containing (a) a functional group which is capable of reacting with the functional group of the fine particles and (b) a water repellent fluorinated group; a binder resin for binding the fine particles; and a solvent for the binder.

Abstract: In an electrochemical detection method using an apparatus including a first vessel and a second vessel, a reference electrolytic solution in the second vessel, first and second closely spaced working electrodes immersed in a sample solution for measurement in the first vessel, a stripping electrode immersed in the reference electrolytic solution, and an ionic conductor arranged between the first vessel and the second vessel, the reference electrolytic solution contains an electrolyte which can be deposited and dissolved by an electrochemical reaction by applying a potential to the stripping electrode. In a first stage, a pre-electrolysis potential is applied to the first working electrode with the stripping electrode being connected to the second working electrode to deposit the electrolyte in the reference electrolytic solution on the stripping electrode.