From: Frank Stewart <hfstew**At_Symbol_Here**NETVIGATOR.COM>
Subject: Re: [DCHAS-L] HPLC solvent disposal
Date: Wed, 5 Oct 2016 21:40:11 +1000
Reply-To: ACS Division of Chemical Health and Safety <DCHAS-L**At_Symbol_Here**PRINCETON.EDU>
Message-ID: 6EC3BA8B-BDED-4E3E-B2E3-9E9E52F3C84B**At_Symbol_Here**
In-Reply-To <9138b1a6-39ce-5ac3-b1e6-a2dab8e7487a**At_Symbol_Here**>

I hope that one of you look up the properties of trifluoroacetic acid in the Merck Index. I do not think any of you would like this chemical in your drains!


Sent from my iPad

> On 5 Oct, 2016, at 3:37 pm, davivid wrote:
> The pKa of trifluoroacetic acid is about -0.3. Acetic acid has a pKa of 4.7. So HOAc is much less acidic that TFA.
> A nice thing about esters is they moderate the pH of both acids and bases and can be readily added to aqueous organic streams without falling into the category of "treatment".
> Dave
>> On 4/10/16 2:05 PM, Sandra K Koster wrote:
>> Ethyl acetate would reduce the acidity of the solution by diluting the trifluoroacetic acid but upon hydrolysis the ethyl acetate should give acetic acid and ethanol. The acetic acid is an acid as its name implies so it should not reduce acidity. Is there something I am missing?
>> Sandra Koster
>> University of Wisconsin-La Crosse
>> ________________________________
>> From: ACS Division of Chemical Health and Safety on behalf of davivid
>> Sent: Tuesday, October 4, 2016 2:54:12 PM
>> To: DCHAS-L**At_Symbol_Here**PRINCETON.EDU
>> Subject: Re: [DCHAS-L] HPLC solvent disposal
>> The mixture is likely corrosive as well as flammable. Adding ethyl
>> acetate to an aqueous flammable/corrosive mixture will bring the pH into
>> the non-corrosive range given time for hydrolysis to occur.
>> Dave
>>> On 4/10/16 11:40 AM, Jerome J King wrote:
>>> Laurie:
>>> Like John indicated, I also work in a production laboratory and we drum all our HPLC waste for removal by a licensed waste hauler.
>>> Jerry King
>>> Jerome King | Technical Director
>>> 13611 B Street Omaha, NE 68144
>>> Office 402-829-9890 Cell 402-658-5005
>>> email | map | website

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