Date: Sat, 16 Jun 2007 13:45:49 -0500
Reply-To: Paul Grasso <pgra**At_Symbol_Here**USA.COM>
Sender: DCHAS-L Discussion List <DCHAS-L**At_Symbol_Here**LIST.UVM.EDU>
From: Paul Grasso <pgra**At_Symbol_Here**USA.COM>
Subject: Re: ZnI question
Comments: To: roger.o.mcclellan**At_Symbol_Here**ATT.NET

Suggest decomposition (hydrolysis) reaction due to heat be avoided by
using Rotovac or other rotary vacuum evaporator to strip off excess
water.   To avoid mechanical vacuum pump with dry ice trap use a  water
aspirator (recycle the water if possible).  (
Recycle and reuse is preferable to (expensively) "properly dispose of"
and (expensively) buying new zinc iodide.   Since the dense zinc iodide
solution is seemingly being used for its physical rather than chemical
properties small amts of impurities may be irrelevant; a few drops of
dilute sodium thiosulfate solution should clear up any purple/brown free
iodine/ triiodide ion impurity.     Paul Grasso, BS,MS,RPh  (https://chemin

  ----- Original Message -----
  From: roger.o.mcclellan**At_Symbol_Here**ATT.NET
  To: DCHAS-L**At_Symbol_Here**LIST.UVM.EDU
  Subject: Re: [DCHAS-L] Fw: [DCHAS-L] ZnI question
  Date: Thu, 14 Jun 2007 16:09:04 +0000

  "Penny wise, pound foolish"
  To All:
  Zinc compounds generally have low toxicity, however, it is
  well-known that freshly generated zinc oxide can be very hazardous.
  Thus, care should be taken in using any procedure to concentrate a
  solution of zinc iodide that involves high temperatures and has the
  potential for producing fresh "fumes" of zinc oxide. This would
  include the potential for untoward conditions, recall the incident
  of a fewweeks ago wthat resulted in a fire and potentially
  hazardous fumes. As I recall that procedure was being carried out
  in a fume hood with no one present. In some cases, it is better to
  appropriately dispose of materials and purchase new reagents. The
  ultimate cost may be lower than that associated with attempting to
  recover reagents.

  Roger O. McClellan, DVM, MMS, Dipl-Abt, Dipl-ABVT, Fellow-ATS
  Advisor, Toxicology and Human Health Risk Analysis
  13701 Quaking Aspen Place NE
  Albuquerque, NM 87111
  Tel: 505-296-7083
  Fax: 505-296-9573
  E-mail: roger.o.mcclellan**At_Symbol_Here**

  -------------- Original message from Kim Auletta
  : --------------

  > I sent the question on to our Geo/chemist & this was his reply.
  > Hope it helps. Kim Auletta Lab Safety Specialist EH&S Z=6200
  > kauletta**At_Symbol_Here** 632-3032 ----- Forwarded by Kim
  > Auletta/Admin on 06/14/2007 07:42 AM ----- John Parise/CAS
  > 06/14/2007 07:24 AM To Kim Auletta/Admin**At_Symbol_Here**SUNYSB cc Subject Re:
  > Fw: [DCHAS-L] ZnI question Quick reply My guess is heating might
  > lead to hydrolysis - formation of zinc hydroxide and formation of
  > hydroen iodide (ZnI2 + H2O -> Zn(OH)2 + 2HI which then comes off?
  > Acid would drive the reaction towards ZnI2 Try adding acetic (or
  > something else acid that does not react with anything in the
  > system and heating? Actually I just did a google search .... Try
  > this
  > knew I had done this before! About 35 years ago John John B.
  > Parise Professor Department of Geosciences Department of
  > Chemistry State University of New York NY 11794-2100, USA
  > +1-631-632-8196 - office (-8197, -1140, -8158 labs)
  > +1-631-632-8240 (-8140) FAX EPO: John.parise**At_Symbol_Here** Kim
  > Auletta/Admin wrote on 06/14/2007 07:11:11 AM: > THought I'd
  > bounce this email question to you - any thoughts on her problem?
  > > > Kim Auletta > Lab Safety Specialist > EH&S Z=6200 >
  > kauletta**At_Symbol_Here** > 632-3032 > ----- Forwarded by Kim
  > Auletta/Admin on 06/14/2007 07:09 AM ----- > > Debbie Decker >
  > Sent by: DCHAS-L Discussion List > > 06/13/2007 09:14 PM > >
  > Please respond to > Debbie Decker > > To > > DCHAS-L**At_Symbol_Here**LIST.UVM.EDU
  > > > cc > > Subject > > [DCHAS-L] ZnI question > > Greetings: > >
  > Please excuse the cross-posting - I need to cast a wide net. I've
  > > received the following question from a researcher in the
  > Geology > department. > > "I am using Zinc Iodide as a heavy
  > liquid in my current lab procedure. > I would like to re-use it
  > but I am having trouble recycling it, I > dilute it during my
  > procedure and I am having difficulty distilling it > back down to
  > the desired specific gravity. I have built simple > distilling
  > apparatus (heating mantle, boiling flask and graham > condenser)
  > but the vapor that comes off the diluted zinc iodide is >
  > brown/purple and then a metallic film accumulates on the interior
  > of the > condenser. So, it seems like I am distilling more than
  > water. It > produces this purple vapor even at temperatures well
  > below boiling" > > I think she's subliming off the iodine that
  > then plates out on the cool > surfaces of the condenser. But I
  > don't have any creative ideas that > will help her re-use the ZnI
  > solution. > > Thanks for your help, > Debbie >
  > ----------------------- > Debbie M. Decker, Campus Chemical
  > Safety Officer > Environmental Health and Safety > University of
  > California, Davis > 1 Shields Ave. > Davis, CA 95616 >
  > (530)754-7964/(530)752-4527 (FAX) > dmdecker**At_Symbol_Here** >
  > Co-Conspirator to Make the World A > Better Place -- Visit
  > and join the conspiracy

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