On Mon, 28 Dec 1998, A. Erickson wrote:

> Could someone post the recipe/instructions for the dichromate/sulfuric
> acid treatment for DAB?  Thanks!

  It's actually a permanganate, not a dichromate treatment.


  The procedure for acid permanganate oxidation of spent DAB is
  as follows. The measurements need not be very accurate.

    An acid permanganate solution is made by dissolving
    4 g KMnO4 in 100 ml of dilute sulphuric acid (made by
    adding 15 ml conc. H2SO4 slowly and carefully to 85
    ml of water). This solution is stable. (My experience
    is that it's very good at cementing in place the glass
    stoppers or screw caps of bottles containing it.

    Add the solution for disposal to an excess of acidified
    permanganate and leave overnight (in a fume hood if
    the solution contained chloride ions, because these
    will end up as chlorine). Next day, neutralize with
    sodium hydroxide (carefully; the temperature will
    rise) and filter. Leave the filter paper to dry in
    the funnel, then put it in a plastic bag for disposal.

    If you have a large volume of DAB solution, carefully
    add sulphuric acid (150 ml for each litre) and then
    dissolve solid potassium permanganate (40 g for each
    litre).

    Reference: Lunn, G & Sansone, EB (1990). Destruction
      of Hazardous Chemicals in the Laboratory. New York:
      Wiley Interscience.

  John A. Kiernan,
  Department of Anatomy & Cell Biology,
  The University of Western Ontario,
  LONDON,  Canada  N6A 5C1
     (kiernan@uwo.ca)