Dithizone organic solvents containing

Chemical procedures that produce less waste or less hazardous waste are said to be green because they reduce harmful environmental effects. In chemical analyses with dithizone, you can substitute aqueous micelles (Box 26-1) for the organic phase (which has traditionally been chloroform, CHC13) to eliminate chlorinated solvent and the tedious extraction.2 For example, a solution containing 5.0 wt% of the micelle-forming surfactant Triton X-100 dissolves 8.3 X 10 5M dithizone at 25°C and pH < 7. The concentration of dithizone inside the micelles, which constitute a small fraction of the volume of solution, is much greater than 8.3 X 10 5M. Aqueous micellar solutions of dithizone can be used for the spectrophotometric analysis of metals such as Zn(II), Cd(Il), Hg(Il), Cu(ll), and Pb(II) with results comparable to those obtained with an organic solvent. 

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