This work presents a cloud-point extraction process using the micelle-mediated extraction method for
simultaneous preconcentration and determination of Sb(III) and Sb(V) species in biological and environmental
samples as a prior preconcentration step to their spectrophotometric determination. The
analytical system is based on the selective reaction between Sb(III) and 3-dichloro-6-(3-carboxy-2-
hydroxy-1-naphthylazo)quinoxaline (DCHNAQ) in the presence of cetyltrimethylammonium bromide
(CTAB) and potassium iodide at pH 4.5. Total Sb concentrationwas determined after reduction of Sb(V) to
Sb(III) in the presence of potassium iodide and ascorbic acid. The optimal reaction conditions and
extraction were studied, and the analytical characteristics of the method (e.g., limits of detection and
quantification, linear range, preconcentration, improvement factors) were obtained. Linearity for Sb(III)
was obeyed in the range of 0.2e20 ng ml
1. The detection and quantification limits for the determination
of Sb(III) were 0.055 and 0.185 ng ml
1, respectively. The method has a lower detection limit and wider
linear range, inexpensive instrument, and low cost, and is more sensitive compared with most other
methods. The interference effect of some anions and cations was also studied. The method was applied to
the determination of Sb(III) in the presence of Sb(V) and total antimony in blood plasma, urine, biological,
and water samples.