{"id":51790,"date":"2014-03-05T13:30:00","date_gmt":"2014-03-05T13:30:00","guid":{"rendered":"https:\/\/discover.restek.com\/uncategorized\/shoot-and-dilute-gc-used-motor-oil-and-pahs-rxi-5ms-gc-column-performance\/"},"modified":"2026-01-28T16:00:44","modified_gmt":"2026-01-28T16:00:44","slug":"shoot-and-dilute-gc-used-motor-oil-and-pahs-rxi-5ms-gc-column-performance","status":"publish","type":"post","link":"https:\/\/discover.restek.com\/it\/blogs\/gnbl4793\/shoot-and-dilute-gc-used-motor-oil-and-pahs-rxi-5ms-gc-column-performance","title":{"rendered":"Shoot-and-Dilute GC \u2013 Used Motor Oil and PAHs \u2013 Rxi-5ms GC Column Performance"},"content":{"rendered":"\n

In a previous post, I introduced the Shoot-and-Dilute GC concept to keep GC systems up longer.   A split injection with a Restek Premium Precision split inlet liner with wool pays huge dividends in good sample transfer of active and polar and involatile analytes while simultaneously reducing the impact of \u201cdirt\u201d on the expensive GC column.<\/p>\n\n\n\n

In that experiment, I made 200 1\u00b5L split injections (10:1) of used motor oil at 5000 ng\/\u00b5L interspersed with PAH standards to determine if \u201cdirt\u201d in the inlet over time could impact the transfer of the less volatile PAHs (e.g. indeno[1,2,3-cd]pyrene, dibenz[ah]anthracene, benzo[ghi]perylene).  As reported in that earlier post, there was no significant degradation of peak response for the PAHs even though 1000 \u00b5g of used motor oil had been injected in the GC inlet liner.  What I didn\u2019t show was the impact on the GC column.  Read on\u2026<\/p>\n\n\n\n

Example used motor oil chromatograms at 5000 and 50,000 ng\/\u00b5L are overlaid with a PAH standard at 2 ng\/\u00b5L in the first figure below to give the ChromaBLOGraphy reader an idea of compound response.  It\u2019s important to note that even though much of the used motor oil gas chromatographs, there are also many involatile hydrocarbons, and potentially, metals, that don\u2019t chromatograph, or don\u2019t even make it out of the GC inlet liner.  The next figure of non-baseline corrected chromatograms illustrates not only how PAH response is about the same after all the used motor oil injections (Shoot-and-Dilute is working as advertised!), but also shows the ruggedness for the 15m x 0.25mm x 0.25\u00b5m Rxi-5ms GC column.  Column bleed at 330\u00b0C, which in this case is probably less volatile components of used motor oil baking out, has barely increased during the life of this experiment.  Based on the number of analyses up to this point and the oven temperature program, the column has spent over 22 hours at 330\u00b0C.<\/p>\n\n\n\n

Astute readers likely noticed that I mentioned 50,000 ng\/\u00b5L used motor oil injections, but didn\u2019t show any data yet for that work.  Stay tuned to Shoot-and-Dilute TV!<\/p>\n\n\n

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Products Mentioned<\/h3>\n
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\n Catalog No. 13420 <\/a> <\/div>\n
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Colonna capillare GC Rxi-5ms, 15 m, ID 0,25 mm, 0,25 \u00b5m<\/div>\n <\/div>\n
\n Esplora Prodotto<\/a>\n <\/div>\n <\/div>\n <\/div>\n <\/div>\n \n\n\n
<\/div>\n","protected":false},"excerpt":{"rendered":"

In a previous post, I introduced the Shoot-and-Dilute GC concept to keep GC systems up longer. A split injection with a Restek Premium Precision split inlet liner with wool pays huge dividends in good sample transfer of active and polar…<\/p>\n","protected":false},"author":1,"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":[9],"tags":[],"industries-application":[2163,2161,2164,2668,2166],"post-badge":[],"resource-type":[],"product-library":[],"resource-technique":[2294,2298],"hf_cat_post":[623],"ppma_author":[590],"class_list":["post-51790","post","type-post","status-publish","format-standard","hentry","category-blogs","industries-application-drinking-water-wastewater-testing","industries-application-environmental","industries-application-industrial-hygiene","industries-application-semivolatiles","industries-application-soil-sediment-biota-testing","resource-technique-gas-chromatography-gc","resource-technique-injection-techniques"],"acf":[],"taxonomy_info":{"category":[{"value":9,"label":"Blogs"}],"industries-application":[{"value":2163,"label":"Drinking Water & Wastewater Testing"},{"value":2161,"label":"Environmental"},{"value":2164,"label":"Industrial Hygiene"},{"value":2668,"label":"Semivolatiles"},{"value":2166,"label":"Soil, Sediment, Biota Testing"}],"resource-technique":[{"value":2294,"label":"Gas Chromatography (GC)"},{"value":2298,"label":"Injection Techniques"}]},"featured_image_src_large":false,"author_info":{"display_name":"DRCadmin","author_link":"https:\/\/discover.restek.com\/it\/author\/drcadmin\/"},"comment_info":0,"category_info":[{"term_id":9,"name":"Blogs","slug":"blogs","term_group":0,"term_taxonomy_id":9,"taxonomy":"category","description":"","parent":0,"count":442,"filter":"raw","cat_ID":9,"category_count":442,"category_description":"","cat_name":"Blogs","category_nicename":"blogs","category_parent":0}],"tag_info":false,"authors":[{"term_id":590,"user_id":0,"is_guest":1,"slug":"jack-cochran","display_name":"Jack Cochran","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\/51790","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\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/discover.restek.com\/it\/wp-json\/wp\/v2\/comments?post=51790"}],"version-history":[{"count":4,"href":"https:\/\/discover.restek.com\/it\/wp-json\/wp\/v2\/posts\/51790\/revisions"}],"predecessor-version":[{"id":85476,"href":"https:\/\/discover.restek.com\/it\/wp-json\/wp\/v2\/posts\/51790\/revisions\/85476"}],"wp:attachment":[{"href":"https:\/\/discover.restek.com\/it\/wp-json\/wp\/v2\/media?parent=51790"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/discover.restek.com\/it\/wp-json\/wp\/v2\/categories?post=51790"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/discover.restek.com\/it\/wp-json\/wp\/v2\/tags?post=51790"},{"taxonomy":"industries-application","embeddable":true,"href":"https:\/\/discover.restek.com\/it\/wp-json\/wp\/v2\/industries-application?post=51790"},{"taxonomy":"post-badge","embeddable":true,"href":"https:\/\/discover.restek.com\/it\/wp-json\/wp\/v2\/post-badge?post=51790"},{"taxonomy":"resource-type","embeddable":true,"href":"https:\/\/discover.restek.com\/it\/wp-json\/wp\/v2\/resource-type?post=51790"},{"taxonomy":"product-library","embeddable":true,"href":"https:\/\/discover.restek.com\/it\/wp-json\/wp\/v2\/product-library?post=51790"},{"taxonomy":"resource-technique","embeddable":true,"href":"https:\/\/discover.restek.com\/it\/wp-json\/wp\/v2\/resource-technique?post=51790"},{"taxonomy":"hf_cat_post","embeddable":true,"href":"https:\/\/discover.restek.com\/it\/wp-json\/wp\/v2\/hf_cat_post?post=51790"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/discover.restek.com\/it\/wp-json\/wp\/v2\/ppma_author?post=51790"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}