{"id":51797,"date":"2011-06-23T14:30:00","date_gmt":"2011-06-23T14:30:00","guid":{"rendered":"https:\/\/discover.restek.com\/uncategorized\/split-injections-the-good-the-bad-and-the-ugly\/"},"modified":"2026-01-28T16:00:59","modified_gmt":"2026-01-28T16:00:59","slug":"split-injections-the-good-the-bad-and-the-ugly","status":"publish","type":"post","link":"https:\/\/discover.restek.com\/zh-hans\/blogs\/gnbl4802\/split-injections-the-good-the-bad-and-the-ugly","title":{"rendered":"Split Injections\u2026 The Good, The Bad and The Ugly"},"content":{"rendered":"\n

While I\u2019m not necessarily a fan of the old spaghetti western film with Clint Eastwood, I thought it was an appropriate title for what I have seen with my work using a split injection for EPA Method 8270 extracts.  You may recall an earlier blog that I wrote about the benefits of a split injection titled “Split Injections Increase your Throughput for Semivolatiles Analysis by EPA Method 8270”.<\/p>\n\n\n\n

for these dirty extracts.  So let\u2019s start with the good.  Using a split injection can allow for an increased initial oven temperature (80\u00b0C) versus a splitless injection (45\u00b0C) because of the faster transfer of analytes through the injection port onto the head of the column.  This gives faster analysis times and much faster oven cool-down times, meaning more samples analyzed in a 12hr period.  I also noticed increased injection-to-injection repeatability and held a continuing calibration longer before instrument maintenance was needed.<\/p>\n\n\n\n

This brings me to the bad…  Of course with a 10:1 split there is a compromise in sensitivity.  With an Agilent 5975 MSD I was able to get a nice linear calibration curve from 5 \u2013 160 \u00b5g\/mL (0.5 to 16 ng on-column).  Going down to 1 \u00b5g\/mL was possible for most compounds with a few exceptions for those troublemaker phenols (2,4-dinitrophenol – I am talking about you!).  On a positive note, by decreasing the sample amount injected onto a 0.25mm ID x 0.25\u00b5m column, sample overloading is minimized. So maybe bad is a little harsh, but it goes with the theme.<\/p>\n\n\n

\n
\"\"<\/figure>\n<\/div>\n\n\n

Finally, let\u2019s finish with the ugly, and I do mean ugly!  After injecting over 300 soil extracts from an underground storage tank site I performed maintenance on my split gas line.  When I took off the line that goes from the injection port to the EPC I couldn\u2019t believe my eyes.  Not sure ugly cuts it here, I think my words were more like disgusting!  A simple rinse with some methylene chloride shined it right back up to looking new. Anyways, lesson learned, there are great benefits to using a split injection for Semivolatiles analysis if you can afford to lose some sensitivity, but make sure to do some routine maintenance on your split lines.<\/p>\n\n\n\n

<\/div>\n","protected":false},"excerpt":{"rendered":"

While I’m not necessarily a fan of the old spaghetti western film with Clint Eastwood, I thought it was an appropriate title for what I have seen with my work using a split injection for EPA Method 8270 extracts. You…<\/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":[9],"tags":[],"industries-application":[],"post-badge":[],"resource-type":[],"product-library":[],"resource-technique":[2332,2333],"hf_cat_post":[623],"ppma_author":[600],"class_list":["post-51797","post","type-post","status-publish","format-standard","hentry","category-blogs","resource-technique-gascromatografia-gc","resource-technique-tecniche-di-iniezione"],"acf":[],"taxonomy_info":{"category":[{"value":9,"label":"Blogs"}],"resource-technique":[{"value":2332,"label":"Gascromatografia (GC)"},{"value":2333,"label":"Tecniche di Iniezione"}]},"featured_image_src_large":false,"author_info":{"display_name":"Patrick Gallagher","author_link":"https:\/\/discover.restek.com\/zh-hans\/author\/patrick-gallagherrestek-com\/"},"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":600,"user_id":0,"is_guest":1,"slug":"michelle-misselwitz","display_name":"Michelle Misselwitz","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\/zh-hans\/wp-json\/wp\/v2\/posts\/51797","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/discover.restek.com\/zh-hans\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/discover.restek.com\/zh-hans\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/discover.restek.com\/zh-hans\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/discover.restek.com\/zh-hans\/wp-json\/wp\/v2\/comments?post=51797"}],"version-history":[{"count":3,"href":"https:\/\/discover.restek.com\/zh-hans\/wp-json\/wp\/v2\/posts\/51797\/revisions"}],"predecessor-version":[{"id":85483,"href":"https:\/\/discover.restek.com\/zh-hans\/wp-json\/wp\/v2\/posts\/51797\/revisions\/85483"}],"wp:attachment":[{"href":"https:\/\/discover.restek.com\/zh-hans\/wp-json\/wp\/v2\/media?parent=51797"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/discover.restek.com\/zh-hans\/wp-json\/wp\/v2\/categories?post=51797"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/discover.restek.com\/zh-hans\/wp-json\/wp\/v2\/tags?post=51797"},{"taxonomy":"industries-application","embeddable":true,"href":"https:\/\/discover.restek.com\/zh-hans\/wp-json\/wp\/v2\/industries-application?post=51797"},{"taxonomy":"post-badge","embeddable":true,"href":"https:\/\/discover.restek.com\/zh-hans\/wp-json\/wp\/v2\/post-badge?post=51797"},{"taxonomy":"resource-type","embeddable":true,"href":"https:\/\/discover.restek.com\/zh-hans\/wp-json\/wp\/v2\/resource-type?post=51797"},{"taxonomy":"product-library","embeddable":true,"href":"https:\/\/discover.restek.com\/zh-hans\/wp-json\/wp\/v2\/product-library?post=51797"},{"taxonomy":"resource-technique","embeddable":true,"href":"https:\/\/discover.restek.com\/zh-hans\/wp-json\/wp\/v2\/resource-technique?post=51797"},{"taxonomy":"hf_cat_post","embeddable":true,"href":"https:\/\/discover.restek.com\/zh-hans\/wp-json\/wp\/v2\/hf_cat_post?post=51797"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/discover.restek.com\/zh-hans\/wp-json\/wp\/v2\/ppma_author?post=51797"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}