3.2. Effect of KI concentration
The concentration of KI that was used to react with nitrite was
optimized. The results shown in Fig. 2 indicate that the highest
absorbance for triiodide extracted into non-ionic surfactant is obtained
when KI concentration was 4.4×10
−3
mol L−1
. Further experiments
were performed by adding 5.5 mL of 0.02 mol L
−1
KI to the 25 mL
solution in order to achieve this concentration.