The phase-separation phenomenon of non-ionic surfactants occurring in aqueous solution
was used for the extraction of cadmium(II), lead(II), palladium(II) and silver(I).
The analytical procedure involved the formation of understudy metals complex with
bis((1H-benzo [d] imidazol-2yl)ethyl) sulfane (BIES), and quantitatively extracted
to the phase rich in octylphenoxypolyethoxyethanol (Triton X-114) after centrifugation.
Methanol acidified with 1molL(-1) HNO(3) was added to the surfactant-rich phase prior
to its analysis by flame atomic absorption spectrometry (FAAS). The concentration
of BIES, pH and amount of surfactant (Triton X-114) was optimized. At optimum conditions,
the detection limits of (3 sdb/m) of 1.4, 2.8, 1.6 and 1.4 ng mL(-1) for Cd(2+), Pb(2+),
Pd(2+) and Ag(+) along with preconcentration factors of 30 and enrichment factors
of 48, 39, 32 and 42 for Cd(2+), Pb(2+), Pd(2+) and Ag(+), respectively, were obtained.
The proposed cloud point extraction has been successfully applied for the determination
of metal ions in real samples with complicated matrix such as radiology waste, vegetable,
blood and urine samples.