{"id":51789,"date":"2015-02-24T13:30:00","date_gmt":"2015-02-24T13:30:00","guid":{"rendered":"https:\/\/discover.restek.com\/uncategorized\/shifting-analyte-retention-times-or-matrix-interferences\/"},"modified":"2025-11-26T20:00:28","modified_gmt":"2025-11-26T20:00:28","slug":"shifting-analyte-retention-times-or-matrix-interferences","status":"publish","type":"post","link":"https:\/\/discover.restek.com\/ja\/blogs-de\/gnbl4792\/shifting-analyte-retention-times-or-matrix-interferences","title":{"rendered":"Shifting Analyte Retention Times or Matrix Interferences?"},"content":{"rendered":"\n<p>Occasionally, we will get a Technical Service call about peak retention times moving during a customer analysis.&nbsp; Early eluting compounds are especially prone to this shifting, but the issue can often be attributed to matrix interferences that are also not well retained.&nbsp; Pregabalin and Gabapentin are two antiepileptic drugs typically analyzed by LC-MS\/MS.&nbsp; Because of their small, polar nature, they may be difficult to retain using reversed phase chromatography.<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"544\" height=\"231\" src=\"https:\/\/discover.restek.com\/wp-content\/uploads\/blog-shifting-analyte-retention-times-or-matrix-interferences-01.png\" alt=\"\" class=\"wp-image-16726\" title=\"-\" srcset=\"https:\/\/discover.restek.com\/wp-content\/uploads\/blog-shifting-analyte-retention-times-or-matrix-interferences-01.png 544w, https:\/\/discover.restek.com\/wp-content\/uploads\/blog-shifting-analyte-retention-times-or-matrix-interferences-01-300x127.png 300w\" sizes=\"auto, (max-width: 544px) 100vw, 544px\" \/><\/figure>\n<\/div>\n\n\n<p>In our example of an antiepileptic drug panel, Pregabalin and Gabapentin are well retained on the&nbsp;Raptor&nbsp;Biphenyl&nbsp;column.<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"556\" height=\"288\" src=\"https:\/\/discover.restek.com\/wp-content\/uploads\/blog-shifting-analyte-retention-times-or-matrix-interferences-02.png\" alt=\"\" class=\"wp-image-16732\" title=\"-\" srcset=\"https:\/\/discover.restek.com\/wp-content\/uploads\/blog-shifting-analyte-retention-times-or-matrix-interferences-02.png 556w, https:\/\/discover.restek.com\/wp-content\/uploads\/blog-shifting-analyte-retention-times-or-matrix-interferences-02-300x155.png 300w\" sizes=\"auto, (max-width: 556px) 100vw, 556px\" \/><\/figure>\n<\/div>\n\n\n<p>&nbsp;These two analytes can be accurately quantitated and results are reproducible when looking across different column lots:<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"450\" height=\"109\" src=\"https:\/\/discover.restek.com\/wp-content\/uploads\/blog-shifting-analyte-retention-times-or-matrix-interferences-03.png\" alt=\"\" class=\"wp-image-16738\" title=\"-\" srcset=\"https:\/\/discover.restek.com\/wp-content\/uploads\/blog-shifting-analyte-retention-times-or-matrix-interferences-03.png 450w, https:\/\/discover.restek.com\/wp-content\/uploads\/blog-shifting-analyte-retention-times-or-matrix-interferences-03-300x73.png 300w\" sizes=\"auto, (max-width: 450px) 100vw, 450px\" \/><\/figure>\n<\/div>\n\n\n<p>However, when analyzing urine samples using a simple dilute &amp; shoot method, quantitation becomes a bit more difficult.&nbsp;&nbsp; Matrix interferences may give the illusion of peaks moving within the chromatogram.&nbsp;&nbsp; &nbsp;&nbsp;In the example below, a sample chromatogram with 100 ng\/mL of antiepileptic drugs in human urine was diluted 5x with 0.1% formic acid in water. &nbsp;The retention time of the analytes is remaining the same, but there are clear interferences from the matrix components.<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"522\" height=\"397\" src=\"https:\/\/discover.restek.com\/wp-content\/uploads\/blog-shifting-analyte-retention-times-or-matrix-interferences-04.png\" alt=\"\" class=\"wp-image-16744\" title=\"-\" srcset=\"https:\/\/discover.restek.com\/wp-content\/uploads\/blog-shifting-analyte-retention-times-or-matrix-interferences-04.png 522w, https:\/\/discover.restek.com\/wp-content\/uploads\/blog-shifting-analyte-retention-times-or-matrix-interferences-04-300x228.png 300w\" sizes=\"auto, (max-width: 522px) 100vw, 522px\" \/><\/figure>\n<\/div>\n\n\n<p>If we take closer look, and extract the MRM transitions for pregabalin, we can clearly see matrix interferences that could make quantitation difficult.<\/p>\n\n\n<div class=\"wp-block-image\">\n<figure class=\"aligncenter size-full\"><img loading=\"lazy\" decoding=\"async\" width=\"552\" height=\"449\" src=\"https:\/\/discover.restek.com\/wp-content\/uploads\/blog-shifting-analyte-retention-times-or-matrix-interferences-05.png\" alt=\"\" class=\"wp-image-16750\" title=\"-\" srcset=\"https:\/\/discover.restek.com\/wp-content\/uploads\/blog-shifting-analyte-retention-times-or-matrix-interferences-05.png 552w, https:\/\/discover.restek.com\/wp-content\/uploads\/blog-shifting-analyte-retention-times-or-matrix-interferences-05-300x244.png 300w\" sizes=\"auto, (max-width: 552px) 100vw, 552px\" \/><\/figure>\n<\/div>\n\n\n<p><br><br>The next time you see your analyte \u201cshifting\u201d retention time, I would recommend running a solvent standard to rule out the possibility of matrix interferences.&nbsp;&nbsp;&nbsp;&nbsp; For more information on this and other challenging analyses, be sure to come to our Monday morning workshop at MSACL 2015 US in San Diego, CA.<\/p>\n\n\n\n<div style=\"height:100px\" aria-hidden=\"true\" class=\"wp-block-spacer\"><\/div>\n","protected":false},"excerpt":{"rendered":"<p>Occasionally, we will get a Technical Service call about peak retention times moving during a customer analysis. Early eluting compounds are especially prone to this shifting, but the issue can often be attributed to matrix interferences that are also not&#8230;<\/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":[792],"tags":[],"industries-application":[2223,2226,2239,2240],"post-badge":[],"resource-type":[],"product-library":[],"resource-technique":[2326,2328,2363],"ppma_author":[586],"class_list":["post-51789","post","type-post","status-publish","format-standard","hentry","category-blogs-de","industries-application-klinisch","industries-application-klinische-toxikologie","industries-application-forensik","industries-application-forensische-toxikologie","resource-technique-flussigchromatografie","resource-technique-massenspektrometrie-ms","resource-technique-ms-ms-de"],"acf":[],"taxonomy_info":{"category":[{"value":792,"label":"Blogs"}],"industries-application":[{"value":2223,"label":"Klinisch"},{"value":2226,"label":"Klinische Toxikologie"},{"value":2239,"label":"Forensik"},{"value":2240,"label":"Forensische Toxikologie"}],"resource-technique":[{"value":2326,"label":"Fl\u00fcssigchromatografie"},{"value":2328,"label":"Massenspektrometrie (MS)"},{"value":2363,"label":"MS\/MS"}]},"featured_image_src_large":false,"author_info":{"display_name":"DRCadmin","author_link":"https:\/\/discover.restek.com\/ja\/author\/drcadmin\/"},"comment_info":0,"category_info":[{"term_id":792,"name":"Blogs","slug":"blogs-de","term_group":0,"term_taxonomy_id":792,"taxonomy":"category","description":"","parent":0,"count":444,"filter":"raw","cat_ID":792,"category_count":444,"category_description":"","cat_name":"Blogs","category_nicename":"blogs-de","category_parent":0}],"tag_info":false,"authors":[{"term_id":586,"user_id":0,"is_guest":1,"slug":"frances-carroll","display_name":"Frances Carroll","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\/ja\/wp-json\/wp\/v2\/posts\/51789","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/discover.restek.com\/ja\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/discover.restek.com\/ja\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/discover.restek.com\/ja\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/discover.restek.com\/ja\/wp-json\/wp\/v2\/comments?post=51789"}],"version-history":[{"count":2,"href":"https:\/\/discover.restek.com\/ja\/wp-json\/wp\/v2\/posts\/51789\/revisions"}],"predecessor-version":[{"id":58619,"href":"https:\/\/discover.restek.com\/ja\/wp-json\/wp\/v2\/posts\/51789\/revisions\/58619"}],"wp:attachment":[{"href":"https:\/\/discover.restek.com\/ja\/wp-json\/wp\/v2\/media?parent=51789"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/discover.restek.com\/ja\/wp-json\/wp\/v2\/categories?post=51789"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/discover.restek.com\/ja\/wp-json\/wp\/v2\/tags?post=51789"},{"taxonomy":"industries-application","embeddable":true,"href":"https:\/\/discover.restek.com\/ja\/wp-json\/wp\/v2\/industries-application?post=51789"},{"taxonomy":"post-badge","embeddable":true,"href":"https:\/\/discover.restek.com\/ja\/wp-json\/wp\/v2\/post-badge?post=51789"},{"taxonomy":"resource-type","embeddable":true,"href":"https:\/\/discover.restek.com\/ja\/wp-json\/wp\/v2\/resource-type?post=51789"},{"taxonomy":"product-library","embeddable":true,"href":"https:\/\/discover.restek.com\/ja\/wp-json\/wp\/v2\/product-library?post=51789"},{"taxonomy":"resource-technique","embeddable":true,"href":"https:\/\/discover.restek.com\/ja\/wp-json\/wp\/v2\/resource-technique?post=51789"},{"taxonomy":"author","embeddable":true,"href":"https:\/\/discover.restek.com\/ja\/wp-json\/wp\/v2\/ppma_author?post=51789"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}