Swipes

["Brian Fairchild" <Brian_Fairchild@fernald.gov>]

     William,
     
     You wrote:
     
     
     >Date: Tue, 30 Sep 1997 10:45:37 EST
     >From: William Lorenzen <LORENZEN_W@A1.TCH.HARVARD.EDU>
     >Subject: Swipe Testing
     
     >What swipe test media are commonly used when the analytical method is 
     >liquid 
     >scintillation counting?  I am currently using "Whatman" Number 1 
     >filter papers 
     >(42.5mm).
     
     >I know some use cotton swabs for instance...
     
     >Any of you who are conducting wipe tests care to share what you use 
     >and do you 
     >prep. them in any way (wet vs. dry)?
     
     >William A. Lorenzen
     >Children's Hospital
     >Boston, MA 02115
     
     >Phone: 617-355-7516
     >Fax: 617-738-4526
     >E-mail: lorenzen_w@a1.tch.harvard.edu
     
     
     
     I used to work at the Princeton Plasma Physics Laboratory.  We used 
     cotton swabs to smear for Tritium, which we read with an LSC.  We used 
     instrument grade Isopropyl (95%) alcohol to prep our swabs and then 
     placed them in our LSC vials with our OptiFluor.  We tried smearing 
     with and without the alcohol and with other types of media, filters 
     and such, and achieved similar analytical results.
     
     We also used a "cold-finger" cryogenic sample for airborne sample 
     concerns.  We used a burette stand with a 200cc graduated cylinder 
     fastened to it.  We positioned a funnel and LSC vial under the 
     cylinder and then filled the cylinder with liquid nitrogen.  The water 
     vapor in air is condensed on the outside of the cylinder and then 
     drips into the vial, via the funnel.  We then added our OptiFluor.  
     Any airborne contaminant that is a water-seeker will be captured and 
     analyzed.
     
     Hope this helps.
     
     
     Brian Fairchild, OHST
     brian_fairchild@Fernald.gov
     (513) 648-5820
     Fluor Daniel Fernald
     
     This is written, by my hand, without the consent of my employer, as if 
     you care.......