Pyrocatechin Violet—A Selective and Sensitive Reagent for the Spectral and Amperometric Determination of Cu(II)

Abstract

Electroanalytical and spectral techniques have been successfully
utilized for the low level detection of Cu(ll).  These methods proved
that Cu(ll)-PV  stoichiometric ratio is 1 : 2 with stability constant for
the said complex log K_s = 8.4183. The free energy of formation
ΔG^o is found to be  -11.54 kcal mole^-1. Spectral studies have been
carried out at 630 nm. However, the ampemrnetric titrations could
be successfully performed at -1.28  V vs. SCE, the plateau potential
of pyrocatechin violet. The pHs were mentioned at 5.0 ± 0.01 with
Walpole buffer. The reverse L-shaped curves were observed.
Ultramicro and microgram quantities of Cu(ll) could be estimated
without any hindrances; proposed methods are rapid, convenient,
accurate and sensitive under the prescribed experimental conditions.