One of my major problems with the SPME-GC\/MS measurements was the amount of water that entered the GC-MS via the SPME fiber. After dipping the fiber into the sample solution, the amount of water remaining on the fiber after the adsorption process was finished was quite substantial causing a trail of water in the chromatogram and increased column bleeding.<\/p>\n
Since the very beginning I have removed the drop that usually hangs on the protective needle, which covers the fiber during transfer and storage – removal with a lint-free tissue was fine. In order to reduce the water content further I have experimented with drying the fiber in a dry N2<\/sub> stream. For that purpose I have used a glass vial with a septum port (for the fiber) and gas-tight in-\/outlets for N2<\/sub>.<\/p>\n While exposing the fiber for drying I noticed that a second drop of water is always hidden in the needle and only removed by evaporation in the injector port (thus increasing the water load on the column). As a result I am now removing this second drop too. I have also dropped the idea of drying the fiber, because it does not remove any additional water (once the second drop is removed) and I am too afraid anyway to loose compounds through volatilisation in the N2<\/sub>-stream.<\/p>\n By removing both drops of water, my baseline is considerably better and column bleeding was significantly reduced. I am surprised that I have never read about this problem in any of the SPME papers that deal with water analysis, although the problem is a faulty construction of the fiber and the protective needle.<\/p>\n","protected":false},"excerpt":{"rendered":" One of my major problems with the SPME-GC\/MS measurements was the amount of water that entered the GC-MS via the SPME fiber. After dipping the fiber into the sample solution, the amount of water remaining on the fiber after the adsorption process was finished was quite substantial causing a trail of water in the chromatogram … Continue reading Reducing the water content during a GC-MS run<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4],"tags":[],"class_list":["post-43","post","type-post","status-publish","format-standard","hentry","category-research"],"_links":{"self":[{"href":"http:\/\/www.nomad.priv.at\/researchblog\/index.php?rest_route=\/wp\/v2\/posts\/43","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/www.nomad.priv.at\/researchblog\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.nomad.priv.at\/researchblog\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.nomad.priv.at\/researchblog\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.nomad.priv.at\/researchblog\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=43"}],"version-history":[{"count":0,"href":"http:\/\/www.nomad.priv.at\/researchblog\/index.php?rest_route=\/wp\/v2\/posts\/43\/revisions"}],"wp:attachment":[{"href":"http:\/\/www.nomad.priv.at\/researchblog\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=43"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.nomad.priv.at\/researchblog\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=43"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.nomad.priv.at\/researchblog\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=43"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}