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From: Penny Manisco <pmanisco**At_Symbol_Here**G.HMC.EDU>
Subject: Re: [DCHAS-L] Dilute Ethidium Bromide Disposal in California
Date: Aug 10, 2018 15:38 UTC
Reply-To:
ACS Division of Chemical Health and Safety
In-Reply-To:
So, if I am not mistaken 0.5 ug/ml is 0.197 mols per liter EtBr
this is an abstract from
Ethidium bromide: destruction and decontamination of solutions. (Armour Method ( Lunn, G.and E. Sansone)
Ethidium bromide in water, TBE buffer, Mops buffer, and cesium chloride solution may be completely degraded by reaction with sodium nitrite and hypophosphorous acid. Only non-mutagenic reaction mixtures were produced. Destruction was greater than 99.8% in all cases; the limit of detection was 0.5 micrograms ethidium bromide per milliliter of solution. Ethidium bromide also may be removed completely from the above solutions by using Amberlite XAD-16 resin. The limit of detection was 0.05 micrograms ethidium bromide per milliliter of solution (0.27 micrograms/ml when cesium chloride solution was used).
I haven't tested this next method but maybe follow this reaction at slight molar excess of the neutralizing reagents.
Lunn & Sansone Method: For each 100 ml of aqueous EtBr solution:
• Add 5% hypophosphorous acid.• Add 12 ml of 0.5 M sodium nitrite.• Stir briefly and let stand for 20 hours.• Adjust pH to 7-9 using sodium hydroxide.• Pour down drain with copious amounts of water.
-Hope this helps
John Darius Soltes CHMM