To attend the norms concerning to water quality [11]the number
of sample to be analyzed increase with the volume of water
daily processed and to attain this requirement the increase of
the reagent consumption is a natural consequence. The reagent
saving and lowering of waste generation are parameters, which
could be pondered to select an analytical method, considering the
implications associated to the environmental restriction and cost
of analysis. These compromises are very difficulty to be achieved
using manual procedure, nevertheless employing automatic procedures
these goals could be attained mainly by resorting those
based on sequential injection analysis [12,13] or multicommutation
approach