2.4. Optimization procedure
The optimization was performed using full two-level factorial and
Box–Behnken design, considering the factors: RF power, acid concentration
and nebulizer gas flow rate. All these experiments were
performed using a gallium solution of 1.00 mg L−1 in a random order
and triplicates of the center point were determined to evaluate the experimental
error. The curvature test was also performed. The analytical
response was recorded as emission intensity, and the 6.0 STATISTICA
software was used to process the experimental data.