Re: Trapping radioactive material from rotary-vane pump exhaust

Steve (Steve@atrbiotech.com)
Tue, 5 Jan 1999 15:24:52 -0500

>The problem with trapping after the pump stems from two sources. The first
>is that the discharge vapor carries a fair amount of heat with it from the
>pumps mechanical frictional losses. The added heat has to be factored into
>the sizing of the cooling system in the trap to insure a high percentage of
>containment. The other concern is the solvents used in this application
have
>melting points that may be lower than single stage refrigerated traps ( -50
>C with todays refrigerants) . LN2 offers temperatures that are low enough
>for efficient trapping but the process of maintaining fluid levels in the
>dewar flask require constant attention. How about a large bed charcoal trap
>post pump, there are several sizes available.

>-----Original Message-----
>From: swilbert@Imail.neorx.com <swilbert@Imail.neorx.com>
>To: Recipients of ABRF List <abrf@aecom.yu.edu>
>Date: Tuesday, January 05, 1999 1:46 AM
>Subject: Trapping radioactive material from rotary-vane pump exhaust
>
>
>> Hi all,
>>
>> we are planning on analyzing samples containing trace amounts of
>> tritium-labelled compounds using our LC-LCQ system. I am looking for
>> advice on efficiently trapping possibly radioactive exhaust fumes
>> generated when ballasting the rotary-vane pump. Any help is greatly
>> appreciated.
>>
>> Thanks!
>>
>> Sibylle Wilbert
>> NeoRx Corp.
>> 410 West Harrison Street
>> Seattle, WA 98119-4007
>> Phone: (206) 281-4001 ext.250
>>
>>
>>______________________________ Reply Separator
>_________________________________
>>Subject: Buffer make-up programs.
>>Author: "Scharin, Eric" <eric.scharin@Covance.com> at IMail
>>Date: 1/4/99 5:38 PM
>>
>>
>>I used to use a shareware program (of unknown origin) called "Buffer" to
>>aid in buffer make-up. You could pick an acid, input the desired pH (it
>>would tell you if you were out of range), ionic strength, molarity, and
>>temperature and it would output the quantities (per liter) of acid,
>>conjugate base, and salt for the recipe. It really sped up the design
>>of formulation experiments (especially constant ionic strength designs).
>>
>>Unfortunately, the program was written for the Mac, and only ran on
>>older Mac OSs. My question to the list: does anyone know of a Windows
>>program (shareware or otherwise) that will serve the same functional
>>requirements?
>>
>>Thanks.
>>
>>Eric Scharin
>>Technical Services
>>Covance Biotechnology Services
>>
>>
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