<?xml version='1.0' encoding='utf-8'?>
<oai_dc:dc xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd">
  <dc:contributor>Tyler B. Coplen</dc:contributor>
  <dc:creator>Kinga M. Revesz</dc:creator>
  <dc:date>1991</dc:date>
  <dc:description>&lt;p id=""&gt;After 10 days, 3-&amp;mu;mol CO&lt;sub&gt;2&lt;/sub&gt;&amp;nbsp;samples in containers having glass stopcocks with Viton&lt;sup&gt;&amp;reg;&lt;/sup&gt;&amp;nbsp;or FETFE O-rings were enriched in&amp;nbsp;&lt;sup&gt;18&lt;/sup&gt;O by 1.5% as a result of absorption by the elastomer; this amount of enrichment is &amp;sim;20 times greater than the precision of&amp;nbsp;&lt;i&gt;&amp;delta;&lt;/i&gt;&lt;sup&gt;18&lt;/sup&gt;O measurements of most laboratories. No change in&amp;nbsp;&lt;sup&gt;13&lt;/sup&gt;C content was observed. Increasing the sample size to 100 &amp;mu;mol resulted in an&amp;nbsp;&lt;sup&gt;18&lt;/sup&gt;O enrichment of 0.2% and did not affect the&amp;nbsp;&lt;sup&gt;13&lt;/sup&gt;C content.&lt;/p&gt;
&lt;p id=""&gt;Caution needs to be exercised in selecting sample containers for CO&lt;sub&gt;2&lt;/sub&gt;&amp;nbsp;isotope-ratio samples of &amp;lt; 200 &amp;mu;mol. If stopcocks are used in construction of containers for such samples, the use of all-glass stopcocks with Apiezon N&lt;sup&gt;&amp;reg;&lt;/sup&gt;&amp;nbsp;hydrocarbon-based grease will eliminate the fractionation of oxygen isotopes.&lt;/p&gt;</dc:description>
  <dc:format>application/pdf</dc:format>
  <dc:identifier>10.1016/0168-9622(91)90054-Z</dc:identifier>
  <dc:language>en</dc:language>
  <dc:publisher>Elsevier</dc:publisher>
  <dc:title>Caution on the use of Viton® or FETFE® O-rings in carbon dioxide sample containers for δ&lt;sup&gt;18&lt;/sup&gt;0 analysis</dc:title>
  <dc:type>article</dc:type>
</oai_dc:dc>