3.2. System optimization
System optimization was carried out by the univaried method, by taking into account the magnitude of the reference signal (due to the [Cu(BCA)2]3− complex) and its diminution by diffusion of HCN from the sample.
Evaluated parameters and selected values are shown in Table 2.
The first experiments (Fig. 2a and b) were carried out without gas-diffusion with a 100 g L−1CN solution.