{"id":76401,"date":"2010-02-20T00:00:00","date_gmt":"2010-02-20T00:00:00","guid":{"rendered":"https:\/\/discover.restek.com\/?p=76401"},"modified":"2025-12-23T17:47:25","modified_gmt":"2025-12-23T17:47:25","slug":"avoiding-split-peaks-in-gas-chromatography-for-quechers-extracts-in-acetonitrile","status":"publish","type":"post","link":"https:\/\/discover.restek.com\/fr\/blog-it\/gnbl5470\/avoiding-split-peaks-in-gas-chromatography-for-quechers-extracts-in-acetonitrile","title":{"rendered":"Avoiding Split Peaks in Gas Chromatography for QuEChERS Extracts in Acetonitrile"},"content":{"rendered":"<style>.kb-image76401_3c09c7-9c .kb-image-has-overlay:after{opacity:0.3;}<\/style>\n<figure class=\"wp-block-kadence-image kb-image76401_3c09c7-9c size-large\"><img loading=\"lazy\" decoding=\"async\" width=\"1024\" height=\"922\" src=\"https:\/\/discover.restek.com\/wp-content\/uploads\/blog-avoiding-split-peaks-in-gas-chromatography-for-quechers-extracts-in-acetonitrile-01-1024x922.jpg\" alt=\"\" class=\"kb-img wp-image-77129\" title=\"-\" srcset=\"https:\/\/discover.restek.com\/wp-content\/uploads\/blog-avoiding-split-peaks-in-gas-chromatography-for-quechers-extracts-in-acetonitrile-01-1024x922.jpg 1024w, https:\/\/discover.restek.com\/wp-content\/uploads\/blog-avoiding-split-peaks-in-gas-chromatography-for-quechers-extracts-in-acetonitrile-01-300x270.jpg 300w, https:\/\/discover.restek.com\/wp-content\/uploads\/blog-avoiding-split-peaks-in-gas-chromatography-for-quechers-extracts-in-acetonitrile-01-768x692.jpg 768w, https:\/\/discover.restek.com\/wp-content\/uploads\/blog-avoiding-split-peaks-in-gas-chromatography-for-quechers-extracts-in-acetonitrile-01.jpg 1502w\" sizes=\"auto, (max-width: 1024px) 100vw, 1024px\" \/><\/figure>\n\n\n\n<p>Acetonitrile injections don\u2019t damage Rxi-5Sil MS GC columns. But urban legends persist, so analysts sometimes do unnecessary and laborious solvent exchanges for QuEChERS extracts.<\/p>\n\n\n\n<p>A real problem that might warrant solvent exchange is mismatch between the polar solvent acetonitrile and non-polar pesticide GC columns (e.g. DB-5ms, Rxi-5Sil MS). Upon injection, lack of wetting leads to split GC peaks, especially severe for early eluters. Adjusting GC oven start temperatures rarely eliminates the problem.<\/p>\n\n\n\n<p>A simple method for avoiding split GC peaks for acetonitrile extracts is to add toluene to the extract. At 50% toluene, peak splitting is gone, and sensitivity is only reduced by 2 (not even that, considering height reduction of split peaks). Even 25% toluene can eradicate peak splitting. Adding internal standard in toluene to a QuEChERS extract prior to injection is an elegant way to kill two European Starlings with one Accrington brick. And, no solvent exchange!<\/p>\n\n\n\n<div style=\"height:100px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n\n\n\n<p><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Acetonitrile injections don&rsquo;t damage Rxi-5Sil MS GC columns. But urban legends persist, so analysts sometimes do unnecessary and laborious solvent exchanges for QuEChERS extracts. A real problem that might warrant solvent exchange is mismatch between the polar solvent acetonitrile and&#8230;<\/p>\n","protected":false},"author":3,"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":[],"product-library":[],"resource-technique":[],"hf_cat_post":[623],"ppma_author":[590],"class_list":["post-76401","post","type-post","status-publish","format-standard","hentry","category-blog-it"],"acf":[],"taxonomy_info":{"category":[{"value":793,"label":"Blog"}]},"featured_image_src_large":false,"author_info":{"display_name":"Audrey Crater","author_link":"https:\/\/discover.restek.com\/fr\/author\/audrey-craterrestek-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":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\/fr\/wp-json\/wp\/v2\/posts\/76401","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/discover.restek.com\/fr\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/discover.restek.com\/fr\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/discover.restek.com\/fr\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/discover.restek.com\/fr\/wp-json\/wp\/v2\/comments?post=76401"}],"version-history":[{"count":3,"href":"https:\/\/discover.restek.com\/fr\/wp-json\/wp\/v2\/posts\/76401\/revisions"}],"predecessor-version":[{"id":77139,"href":"https:\/\/discover.restek.com\/fr\/wp-json\/wp\/v2\/posts\/76401\/revisions\/77139"}],"wp:attachment":[{"href":"https:\/\/discover.restek.com\/fr\/wp-json\/wp\/v2\/media?parent=76401"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/discover.restek.com\/fr\/wp-json\/wp\/v2\/categories?post=76401"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/discover.restek.com\/fr\/wp-json\/wp\/v2\/tags?post=76401"},{"taxonomy":"industries-application","embeddable":true,"href":"https:\/\/discover.restek.com\/fr\/wp-json\/wp\/v2\/industries-application?post=76401"},{"taxonomy":"post-badge","embeddable":true,"href":"https:\/\/discover.restek.com\/fr\/wp-json\/wp\/v2\/post-badge?post=76401"},{"taxonomy":"resource-type","embeddable":true,"href":"https:\/\/discover.restek.com\/fr\/wp-json\/wp\/v2\/resource-type?post=76401"},{"taxonomy":"product-library","embeddable":true,"href":"https:\/\/discover.restek.com\/fr\/wp-json\/wp\/v2\/product-library?post=76401"},{"taxonomy":"resource-technique","embeddable":true,"href":"https:\/\/discover.restek.com\/fr\/wp-json\/wp\/v2\/resource-technique?post=76401"},{"taxonomy":"hf_cat_post","embeddable":true,"href":"https:\/\/discover.restek.com\/fr\/wp-json\/wp\/v2\/hf_cat_post?post=76401"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/discover.restek.com\/fr\/wp-json\/wp\/v2\/ppma_author?post=76401"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}