Abstract
Scanning electrode quartz crystal analysis (SEQCA) in the back-scanning mode is described. Although qualitative map-ping of the mass distribution on a quartz plate is possible in air or non-conducting liquids by means of SEQCA in the fore-scanning mode, mapping is difficult in an electrolyte solution (e.g. ≥10 mM NaCl), which behaves as an electrode due to its ionic conductivity. On the other hand, because the back-scanning mode does not suffer from the ionic conductivity of a solution, mapping is possible even in a 0.1 M NaCl solution. This technique is applied to electrochemical measurements. An electrode on a quartz plate is partially masked, and polypyrrole is deposited on the bare region by electropolymerization from an electrolyte solution containing pyrrole. The deposited polypyrrole can be located in the elec-trolyte solution by means of SEQCA in the back-scanning mode.
