A single gas chromatograph for accurate atmospheric mixing ratio measurements of CO&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt;, CH&amp;lt;sub&amp;gt;4&amp;lt;/sub&amp;gt;, N&amp;lt;sub&amp;gt;2&amp;lt;/sub&amp;gt;O, SF&amp;lt;sub&amp;gt;6&amp;lt;/sub&amp;gt; and CO
Atmospheric measurement techniques