2.4. Analytical procedure
Ten milliliters of the B–R universal buffer of pH 2 contain-ing the appropriate concentration of nitroxynil were introduced
into a micro-electrolysis cell, then deoxygenated with nitro-gen for 5 min. An accumulation potential of −0.1 V (versus
Ag/AgCl/KCls) was applied to the working electrode for 90 s,
while the solution is stirred. After accumulation time elapsed,
the stirrer was stopped and the solution allowed to be qui-escent about 10 s, then the voltammogram was recorded by
scanning the potential towards the negative direction using the
differential-pulse or the square-wave mode. Calibration curves
were obtained under the optimized conditions of the procedure.
Quantification of nitroxynil in bulk form and formulation was
performed by means of both calibration curve and standard addition methods.