3.2. Effect of the sample pH
The pH of samples plays an important role on the complex formation
and subsequent HF-SLME. The effect of pH on the absorbance
signals of Sb(III) and Sb(V)was evaluated at pH values varying between
0 and 8.0. As can be seen in Fig. 3, Sb(III) was completely extracted in
the pH range of 1.0–6.0, but Sb(V) was not extracted in the pH range of