A new method, electrodeposition frequency shift titrimetry, is suggest
ed, in which a piezoelectric crystal sensor is used as an end-point de
tector, based on its extremely sensitive response to changes in mass l
oading on its surface. This method is more sensitive than the frequenc
y-metric titrations based on the change in conductance and it has a hi
gher selectivity, controlled by the applied potential. Aqueous cyanide
was detected by this method. (C) 1995 Academic Press, Inc.