{"id":48509,"date":"2012-07-26T14:30:00","date_gmt":"2012-07-26T14:30:00","guid":{"rendered":"https:\/\/discover.restek.com\/uncategorized\/how-to-choose-the-correct-gc-column-part-2\/"},"modified":"2026-01-28T15:54:16","modified_gmt":"2026-01-28T15:54:16","slug":"how-to-choose-the-correct-gc-column-part-2","status":"publish","type":"post","link":"https:\/\/discover.restek.com\/it\/blog-it\/gnbl4704\/how-to-choose-the-correct-gc-column-part-2","title":{"rendered":"How to choose the correct GC column \u2013 Part 2"},"content":{"rendered":"\n<p>My last post looked at how to use published boiling points of compounds to help select a GC column. In this post, I will be discussing the role of compound polarity when selecting a GC column.<\/p>\n\n\n\n<p>To briefly summarize my column selection process (discussed in\u00a0How to choose the correct GC column \u2013 Part 1\u00a0)<\/p>\n\n\n\n<figure class=\"wp-block-embed is-type-wp-embed is-provider-wordpress-embed wp-block-embed-wordpress-embed\"><div class=\"wp-block-embed__wrapper\">\n<blockquote class=\"wp-embedded-content\" data-secret=\"JqcxwSNV2e\"><a href=\"https:\/\/discover.restek.com\/gnbl4703\/how-to-choose-the-correct-gc-column-part-1\/\">How to choose the correct GC column &ndash; Part 1<\/a><\/blockquote><iframe loading=\"lazy\" class=\"wp-embedded-content\" sandbox=\"allow-scripts\" security=\"restricted\" style=\"position: absolute; visibility: hidden;\" title=\"&#8220;How to choose the correct GC column &ndash; Part 1&#8221; &#8212; \" src=\"https:\/\/discover.restek.com\/gnbl4703\/how-to-choose-the-correct-gc-column-part-1\/embed\/#?secret=URrNmqXJYO#?secret=JqcxwSNV2e\" data-secret=\"JqcxwSNV2e\" width=\"600\" height=\"338\" frameborder=\"0\" marginwidth=\"0\" marginheight=\"0\" scrolling=\"no\"><\/iframe>\n<\/div><\/figure>\n\n\n\n<p><em><strong>My four categories of narrowing down column selection:<\/strong><\/em><\/p>\n\n\n\n<p>1.&nbsp; I look at the published&nbsp;<strong>boiling points&nbsp;<\/strong>of the compounds of interest.<\/p>\n\n\n\n<p>2.&nbsp; I consider the&nbsp;<strong>polarity<\/strong>&nbsp;of the compounds (and polarity of the sample\/standard solvent, if applicable).<\/p>\n\n\n\n<p>3.&nbsp; I consider compound&nbsp;<strong>concentrations, column capacities, and detector used<\/strong>.<\/p>\n\n\n\n<p>4.&nbsp; I look at any other&nbsp;<strong>details<\/strong>&nbsp;which may help narrow down the choice to just one, or a handful, of column catalog numbers.<\/p>\n\n\n\n<p>I use the four categories listed above to help narrow down possible column choices into one of the four categories listed below.<\/p>\n\n\n\n<p><em><strong>My four categories of GC columns:<\/strong><\/em><\/p>\n\n\n\n<p>A. Gas analysis columns (carbon &amp; zeolite molecular sieves, porous polymers, silica gel, etc.).<\/p>\n\n\n\n<p>B. Volatile columns (Rtx-VMS, Rxi-624Silms, Rtx-502.2, etc.).<\/p>\n\n\n\n<p>C. Semi-volatile columns (Rxi-5Silms, Rxi-35Silms, Rxi-17Silms, etc.).<\/p>\n\n\n\n<p>D. High-temperature columns (MXT-Biodiesel, MXT-1HT, MXT-2887, etc.).<\/p>\n\n\n\n<p>For those unfamiliar with chemical (molecular)&nbsp;<strong>polarity<\/strong>, in very generic terms, think of straight-chain hydrocarbons (with their symmetrical C-H bonds and equal sharing of electrons) at one end of the scale (non-polar), and alcohols\/water (with their unsymmetrical O-H bonds and unequal sharing of electrons) at the other end (polar).<\/p>\n\n\n\n<p class=\"has-text-align-center\"><a href=\"http:\/\/en.wikipedia.org\/wiki\/Chemical_polarity\" target=\"_blank\" rel=\"noreferrer noopener\">Chemical polarity<\/a><\/p>\n\n\n\n<p class=\"has-text-align-center\">Structure of (<em>non-polar<\/em>)&nbsp;methane (from Wikipedia)<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"100\" height=\"117\" src=\"https:\/\/discover.restek.com\/wp-content\/uploads\/blog-how-to-choose-the-correct-gc-column-part-2-01.png\" alt=\"\" class=\"wp-image-15130\" title=\"-\"><\/figure>\n<\/div>\n\n\n<p class=\"has-text-align-center\">Structure of (<em>polar<\/em>)&nbsp;methanol (from Wikipedia)<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"180\" height=\"116\" src=\"https:\/\/discover.restek.com\/wp-content\/uploads\/blog-how-to-choose-the-correct-gc-column-part-2-02.png\" alt=\"\" class=\"wp-image-15136\" title=\"-\"><\/figure>\n<\/div>\n\n\n<p>You can also think of polarity another way; remember the statement \u201clike dissolves like\u201d? If so, the solvent used to prepare your standards may be all you need to know since, for solubility and stability, compounds are typically prepared in a solvent of similar polarity. For example, this is why straight-chain hydrocarbons (non-polar) will be prepared in a non-polar solvent (like hexane, toluene or carbon disulfide).<\/p>\n\n\n\n<p>I prefer to use tables for polarity information on many compounds and solvents.<\/p>\n\n\n\n<p class=\"has-text-align-center\"><a href=\"http:\/\/murov.info\/orgsolvents.htm\" target=\"_blank\" rel=\"noreferrer noopener\">Properties of organic solvents<\/a><\/p>\n\n\n\n<p class=\"has-text-align-center\"><a href=\"http:\/\/en.wikipedia.org\/wiki\/Solvent\" target=\"_blank\" rel=\"noreferrer noopener\">Physical properties of common solvents<\/a><\/p>\n\n\n\n<p>So now that you see there are resources available, how do you use this information to help narrow down column selection?\u00a0<em>Generally speaking<\/em>, choosing a column with a phase of similar polarity as the compounds (&amp; solvent) will provide the most compound retention and have proper wettability (\u00a0<a href=\"https:\/\/en.wikipedia.org\/wiki\/Wetting\" target=\"_blank\" rel=\"noreferrer noopener\">Wetting<\/a>\u00a0). Without proper retention, compounds with similar chemical structures may not separate, and without proper wettability, chromatographic issues like split peaks may occur.<\/p>\n\n\n\n<p>While we are on the topic of solvents for samples\/standards, to minimize the possibility of chromatographic issues like split or tailing peaks, I suggest using (whenever possible) GC-friendly solvents like acetone, methylene chloride and hexane and to avoid problematic solvents like chloroform, acetonitrile and water.<\/p>\n\n\n\n<p>Above I provided information to help you determine the polarity of compounds (and solvents). Below I\u2019ll provide examples of different polarity GC columns.<\/p>\n\n\n\n<p><strong>Gas analysis columns<\/strong><\/p>\n\n\n\n<p><em>Non-Polar\/Slightly Polar<\/em>: Rt-Q-Bond, Rt-QS-Bond, Alumina\/KCl, HayeSep Q &amp; D, Chromosorb T&nbsp;<em>Mid-Polarity<\/em>: Rt-S-Bond, HayeSep C, R &amp; S, Alumina\/Na2SO4 &amp; MAPD&nbsp;<em>Polar<\/em>: Rt-U-Bond, HayeSep B, N &amp; T<\/p>\n\n\n\n<p><strong>Volatile columns<\/strong><\/p>\n\n\n\n<p><em>Non-Polar\/Slightly Polar<\/em>: Thick-film Rtx-1 &amp; Rtx-5, Rtx-Volatile Amine&nbsp;<em>Mid-Polarity<\/em>: Rtx-VMS, Rtx-502.2, Rtx-624, Thick-film Rtx-1301 &amp; Rtx-200&nbsp;<em>Polar<\/em>: Stabilwax (including DA &amp; DB) and Rtx-Wax<\/p>\n\n\n\n<p><strong>Semi-Volatile columns<\/strong><\/p>\n\n\n\n<p><em>Non-Polar\/Slightly Polar<\/em>: Thin-film Rxi-1ms, Rxi-5ms, Rxi-5Silms, Rxi-XLB&nbsp;<em>Mid-Polarity<\/em>: Rxi-17 (&amp; 17Silms), Rxi-35Silms, Rtx-50, Thin-film Rtx-200&nbsp;<em>Polar<\/em>: NA<\/p>\n\n\n\n<p><strong>High Temperature columns<\/strong><\/p>\n\n\n\n<p><em>Non-Polar\/Slightly Polar<\/em>: Rxi-1HT, Rxi-5HT, MXT-Biodiesel, MXT-1HT, MXT-1 SimDist&nbsp;<em>Mid-Polarity<\/em>: MXT-65TG <em>Polar<\/em>: NA<\/p>\n\n\n\n<p>So using this post with the previous post, I am hoping that you can see how one can quickly narrow down column selection. My next post will focus on how one can use column capacity (along with detector selection) to help narrow down GC column choices even further. Keep watching for Part 3.<\/p>\n\n\n\n<div style=\"height:100px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n","protected":false},"excerpt":{"rendered":"<p>My last post looked at how to use published boiling points of compounds to help select a GC column. In this post, I will be discussing the role of compound polarity when selecting a GC column. To briefly summarize my&#8230;<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"_kad_blocks_custom_css":"","_kad_blocks_head_custom_js":"","_kad_blocks_body_custom_js":"","_kad_blocks_footer_custom_js":"","_kadence_starter_templates_imported_post":false,"_kad_post_transparent":"","_kad_post_title":"","_kad_post_layout":"","_kad_post_sidebar_id":"","_kad_post_content_style":"","_kad_post_vertical_padding":"","_kad_post_feature":"","_kad_post_feature_position":"","_kad_post_header":false,"_kad_post_footer":false,"footnotes":""},"categories":[793],"tags":[],"industries-application":[],"post-badge":[],"resource-type":[567],"product-library":[],"resource-technique":[2307],"hf_cat_post":[623],"ppma_author":[582],"class_list":["post-48509","post","type-post","status-publish","format-standard","hentry","category-blog-it","resource-type-selection-guides","resource-technique-gas-chromatography-gc-zh"],"acf":[],"taxonomy_info":{"category":[{"value":793,"label":"Blog"}],"resource-type":[{"value":567,"label":"Selection Guides"}],"resource-technique":[{"value":2307,"label":"\u6c14\u76f8\u8272\u8c31\uff08GC\uff09"}]},"featured_image_src_large":false,"author_info":{"display_name":"Patrick Gallagher","author_link":"https:\/\/discover.restek.com\/it\/author\/patrick-gallagherrestek-com\/"},"comment_info":0,"category_info":[{"term_id":793,"name":"Blog","slug":"blog-it","term_group":0,"term_taxonomy_id":793,"taxonomy":"category","description":"","parent":0,"count":442,"filter":"raw","cat_ID":793,"category_count":442,"category_description":"","cat_name":"Blog","category_nicename":"blog-it","category_parent":0}],"tag_info":false,"authors":[{"term_id":582,"user_id":0,"is_guest":1,"slug":"alan-sensue","display_name":"Alan Sensue","avatar_url":"https:\/\/secure.gravatar.com\/avatar\/?s=96&d=mm&r=g","0":null,"1":"","2":"","3":"","4":"","5":"","6":"","7":"","8":""}],"_links":{"self":[{"href":"https:\/\/discover.restek.com\/it\/wp-json\/wp\/v2\/posts\/48509","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/discover.restek.com\/it\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/discover.restek.com\/it\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/discover.restek.com\/it\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/discover.restek.com\/it\/wp-json\/wp\/v2\/comments?post=48509"}],"version-history":[{"count":4,"href":"https:\/\/discover.restek.com\/it\/wp-json\/wp\/v2\/posts\/48509\/revisions"}],"predecessor-version":[{"id":85341,"href":"https:\/\/discover.restek.com\/it\/wp-json\/wp\/v2\/posts\/48509\/revisions\/85341"}],"wp:attachment":[{"href":"https:\/\/discover.restek.com\/it\/wp-json\/wp\/v2\/media?parent=48509"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/discover.restek.com\/it\/wp-json\/wp\/v2\/categories?post=48509"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/discover.restek.com\/it\/wp-json\/wp\/v2\/tags?post=48509"},{"taxonomy":"industries-application","embeddable":true,"href":"https:\/\/discover.restek.com\/it\/wp-json\/wp\/v2\/industries-application?post=48509"},{"taxonomy":"post-badge","embeddable":true,"href":"https:\/\/discover.restek.com\/it\/wp-json\/wp\/v2\/post-badge?post=48509"},{"taxonomy":"resource-type","embeddable":true,"href":"https:\/\/discover.restek.com\/it\/wp-json\/wp\/v2\/resource-type?post=48509"},{"taxonomy":"product-library","embeddable":true,"href":"https:\/\/discover.restek.com\/it\/wp-json\/wp\/v2\/product-library?post=48509"},{"taxonomy":"resource-technique","embeddable":true,"href":"https:\/\/discover.restek.com\/it\/wp-json\/wp\/v2\/resource-technique?post=48509"},{"taxonomy":"hf_cat_post","embeddable":true,"href":"https:\/\/discover.restek.com\/it\/wp-json\/wp\/v2\/hf_cat_post?post=48509"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/discover.restek.com\/it\/wp-json\/wp\/v2\/ppma_author?post=48509"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}