A New Spectrophotometric Method for Determination of Selenium in Cosmetic and Pharmaceutical Preparations after Preconcentration with Cloud Point Extraction
Figure 2
Absorption spectra of (a) dithizone (HDZ) in methanol, (b) Se (IV)-HDZ complex. Conditions: 0.2% (w/v) Triton X-100, 7.5 μmol l−1 HDZ, 0.35 M HCl, 100 ng mL−1 Se (IV), equilibration time: 15 min, and equilibration temperature: 40°C.
