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<p class="MsoNormal">Hi Maria<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I agree with Rob’s comments, below. A couple of additional things to consider:<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"> Zeolites are molecular sieves - they trap and hold whatever they are designed to trap and hold – usually the target is gaseous compounds, not necessarily water vapor.
<o:p></o:p></p>
<p class="MsoNormal"> Zeolites are engineered materials that are designed to do specific things, so check with the manufacturer to understand how the zeolite you want to use will work for your particular application. Perhaps there are alternatives.<o:p></o:p></p>
<p class="MsoNormal"> Zeolites trap whatever they are designed to trap and hold it until they can no longer take up whatever that is – they do no re-release it, but they would become ineffective at some point. It would be important to know when
that happens so you could change out the zeolite as needed.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Hope that helps,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Cathy<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal"><i><span style="font-size:9.0pt"><o:p> </o:p></span></i></p>
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<p class="MsoNormal"><b>From:</b> Nhcoll-l <nhcoll-l-bounces@mailman.yale.edu> <b>
On Behalf Of </b>Robert Waller<br>
<b>Sent:</b> Monday, January 17, 2022 10:58 AM<br>
<b>To:</b> Marta Pérez <marta.perez.cr@gmail.com>; nhcoll-l@mailman.yale.edu<br>
<b>Subject:</b> Re: [Nhcoll-l] Molecular sieve (Zeolite) for conservation<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal" style="line-height:12.0pt;background:#FFEB9C"><b><span style="font-size:9.0pt;color:#9C6500">External Email - Exercise Caution</span></b><o:p></o:p></p>
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<p class="MsoNormal"><span lang="EN-CA">Hi Marta,<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-CA">I assume here you are using the product for initial drying of material. For adsorbing water there should be no fundamental difference between silica gels (different “grades”) and zeolites (different structures). In a
practical sense, you want the largest sorption capacity between the starting relative humidity (I presume close to 100% for fresh material) and the desired relative humidity to be reached. You ought to be able to find that in the technical specifications for
any of those products. If you are using the product for maintaining a lower than room ambient relative humidity in the long term, then characteristic of the packaging are likely more important then which desiccant you choose. Still, optimizing the choice of
desiccant for that purpose would be a matter of choosing the highest sorption capacity between your initial closure relative humidity (very low?) and the collection space average annual relative humidity. Conceivably, there may be an issue of sorption of organic
volatiles but it would be more challenging to identify differences between silica gels and zeolites from that perspective and it may not have any relevance to DNA preservation.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-CA">If the product is to provide long-term low relative humidity control then you should consult with a conservator to determine how to match sorbent, packaging, and maintenance schedule to ensure success.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-CA">Best,<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-CA">Rob<o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><span lang="EN-CA" style="color:black">Robert Waller, PhD, CAPC, FIIC<br>
President and Senior Risk Analyst<br>
Protect Heritage Corp.<br>
622 Simoneau Way<br>
Ottawa ON K4A 1P4<br>
email: </span><span style="color:black"><a href="mailto:rw@protectheritage.com"><span lang="EN-CA" style="color:#0563C1">rw@protectheritage.com</span></a><br>
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</span><span lang="EN-CA" style="color:black">phone: 613-883-2707 (Canada)<br>
phone: 303-872-9739 (USA)<br>
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<p class="MsoNormal"><span lang="EN-CA" style="color:black">skype: rrwaller<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-CA" style="color:black">Research Associate, Canadian Museum of Nature<br>
Adjunct Assistant Professor, Queen’s University<br>
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</span><a href="https://nam02.safelinks.protection.outlook.com/?url=https%3A%2F%2Ftwitter.com%2F%23!%2FProtectHeritage&data=04%7C01%7Chawksc%40si.edu%7C19c5d42d4e734d5fe3c608d9d9d2464d%7C989b5e2a14e44efe93b78cdd5fc5d11c%7C0%7C0%7C637780320006116015%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=KzJY025f9K5CGQmA4NkzmTLsjcg394ND8K0mJWjcgDI%3D&reserved=0"><span lang="EN-CA" style="color:black;text-decoration:none"><img border="0" width="76" height="28" style="width:.7916in;height:.2916in" id="Picture_x0020_7" src="cid:image019.png@01D80C30.A4140A90" alt="image009"></span></a><span lang="EN-CA" style="color:black"><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-CA" style="color:black"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-CA"> <o:p></o:p></span></p>
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<p class="MsoNormal"><b>From:</b> Nhcoll-l <<a href="mailto:nhcoll-l-bounces@mailman.yale.edu">nhcoll-l-bounces@mailman.yale.edu</a>>
<b>On Behalf Of </b>Marta Pérez<br>
<b>Sent:</b> Monday, January 17, 2022 10:36 AM<br>
<b>To:</b> <a href="mailto:nhcoll-l@mailman.yale.edu">nhcoll-l@mailman.yale.edu</a><br>
<b>Subject:</b> [Nhcoll-l] Molecular sieve (Zeolite) for conservation<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">Hello, <span style="font-family:inherit;color:#202124;background:#F8F9FA">I don't know if my message went unnoticed or if nobody has an answer. I ask again, just in case!</span><o:p></o:p></p>
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<p class="MsoNormal">Does anyone have experience in preserving dry tissues with molecular sieve? We are considering testing it for our plant tissue bank instead of other substances previously used, like regular silica gel or Artsorb, because it appears to be
more effective. We found this Zeolite molecular sieve, but maybe you are using other compositions. We are primarily concerned about possible interferences/contamination of this type of preservative in future DNA analysis. <o:p></o:p></p>
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<p class="MsoNormal">Thanks for your answers,<o:p></o:p></p>
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<p class="MsoNormal">Regards,<o:p></o:p></p>
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<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal">Marta Pérez Azcárate<o:p></o:p></p>
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<p class="MsoNormal"><b>Laboratori de Conservació Preventiva i Restauració</b><o:p></o:p></p>
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<p class="MsoNormal" style="margin-bottom:12.0pt">Grop<o:p></o:p></p>
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<p class="MsoNormal">Nat-Museu de Ciències Naturals de Barcelona<o:p></o:p></p>
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<p class="MsoNormal"><b>Laboratori de Natura</b><o:p></o:p></p>
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<p class="MsoNormal">Pg Picasso s/n<o:p></o:p></p>
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<p class="MsoNormal">08003 Barcelona<o:p></o:p></p>
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<p class="MsoNormal">Tel. 932562209<o:p></o:p></p>
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<p class="MsoNormal"><a href="mailto:marta.perez.cr@gmail.com" target="_blank">marta.perez.cr@gmail.com</a><o:p></o:p></p>
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<p class="MsoNormal"><a href="https://nam02.safelinks.protection.outlook.com/?url=http%3A%2F%2Fwww.museuciencies.cat%2Fes&data=04%7C01%7Chawksc%40si.edu%7C19c5d42d4e734d5fe3c608d9d9d2464d%7C989b5e2a14e44efe93b78cdd5fc5d11c%7C0%7C0%7C637780320006116015%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000&sdata=rixXd85oYARWXzX1crD2iZ3RqeizhAvTCgbV5Wc9X2w%3D&reserved=0" target="_blank">https://museuciencies.cat/area-cientifica/serveis-cientifico-tecnics/laboratoris-tecnics/conservacio-preventiva-i-restauracio/</a><o:p></o:p></p>
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