Two-phase aqueous extraction of chromium and its application to speciationanalysis of chromium in plasma

This work proposes a new extraction method for chromium based on the two-ph ase aqueous system isopropyl alcohol-ammonium sulfate-ammonium thiocyanate (i-PrOH-(NH4)(2)SO4-NH4SCN), and the related experimental conditions are op timized. The results show that chromium (III) can be quantitatively extract ed under the selected conditions: 4 mL of i-PrOH, 200 mu L of 2 mol/L sulfu ric acid, 1 mL of 4 mol/L NH4SCN and 3 mL of saturated (NH4)(2)SO4 solution (V-total = 10 mL). Application of the proposed method to speciation analys is of plasma chromium was also investigated and satisfactory results were o btained.