{"id":2240,"date":"1999-01-27T21:49:00","date_gmt":"1999-01-28T03:49:00","guid":{"rendered":"https:\/\/kermitmurray.com\/murray\/?p=2240"},"modified":"2019-08-03T21:26:17","modified_gmt":"2019-08-04T02:26:17","slug":"ir-maldi-using-oh-nh-and-ch-vibrational-absorption","status":"publish","type":"post","link":"https:\/\/kermitmurray.com\/research\/1999\/01\/ir-maldi-using-oh-nh-and-ch-vibrational-absorption\/","title":{"rendered":"Infrared matrix-assisted laser desorption\/ionization using OH, NH and CH vibrational absorption"},"content":{"rendered":"\n<div class=\"wp-block-caxton-grid relative\"><div class=\"absolute absolute--fill\"><div class=\"cover bg-center absolute absolute--fill\" style=\"background-color:;background-image:linear-gradient( );\"><\/div><div class=\"absolute absolute--fill\" style=\"background-color:;background-image:linear-gradient( );opacity:1;\"><\/div><\/div><div class=\"relative caxton-columns caxton-grid-block\" style=\"padding-top:0;padding-left:0;padding-bottom:0;padding-right:0;grid-template-columns:repeat(12, 1fr)\" data-tablet-css=\"padding-left:em;padding-right:em;\" data-mobile-css=\"padding-left:em;padding-right:em;\">\n<div class=\"wp-block-caxton-section relative\" style=\"grid-area:span 1\/span 12\"><div class=\"absolute absolute--fill\"><div class=\"cover bg-center absolute absolute--fill\" style=\"background-color:;background-image:linear-gradient( );\"><\/div><div class=\"absolute absolute--fill\" style=\"background-color:;background-image:linear-gradient( );opacity:1;\"><\/div><\/div><div class=\"relative caxton-section-block\" style=\"padding-top:5px;padding-left:5px;padding-bottom:5px;padding-right:5px\" data-mobile-css=\"padding-left:1em;padding-right:1em;\" data-tablet-css=\"padding-left:1em;padding-right:1em;\">\n<p>J.D. Sheffer, K.K. Murray, Infrared matrix-assisted laser desorption\/ionization using OH, NH and CH vibrational absorption, <em>Rapid Commun. Mass Spectrom.<\/em> <strong>12<\/strong> (1998) 1685-1690; doi:<a href=\"https:\/\/doi.org\/10.1002\/(SICI)1097-0231(19981130)12:22%3C1685::AID-RCM389%3E3.0.CO;2-S\">10.1002\/(SICI)1097-0231(19981130)12:22&lt;1685::AID-RCM389>3.0.CO;2-S<\/a>.<\/p>\n\n\n\n<h4 class=\"wp-block-heading\">Abstract<\/h4>\n\n\n\n<div class=\"wp-block-image\"><figure class=\"alignright is-resized\"><a href=\"https:\/\/kermitmurray.com\/murray\/1999\/01\/ir-maldi-using-oh-nh-and-ch-vibrational-absorption\/sheffer-rcm-1998\/\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/kermitmurray.com\/murray\/wp-content\/uploads\/1999\/01\/Sheffer-RCM-1998-1024x1024.gif\" alt=\"MALDI of bovine insulin with succinic acid matrix \" class=\"wp-image-2370\" width=\"512\" height=\"512\" srcset=\"https:\/\/kermitmurray.com\/research\/wp-content\/uploads\/1999\/01\/Sheffer-RCM-1998-1024x1024.gif 1024w, https:\/\/kermitmurray.com\/research\/wp-content\/uploads\/1999\/01\/Sheffer-RCM-1998-150x150.gif 150w, https:\/\/kermitmurray.com\/research\/wp-content\/uploads\/1999\/01\/Sheffer-RCM-1998-300x300.gif 300w, https:\/\/kermitmurray.com\/research\/wp-content\/uploads\/1999\/01\/Sheffer-RCM-1998-768x768.gif 768w\" sizes=\"auto, (max-width: 512px) 100vw, 512px\" \/><\/a><figcaption>MALDI mass spectra of bovine insulin with succinic acid matrix at 2.90 and 3.50 \u00b5m.<\/figcaption><\/figure><\/div>\n\n\n\n<p>The matrices succinic acid (butanedioc acid), caffeic acid (3,4\u2010dihydroxycinnamic acid), and 4\u2010nitroaniline were used to obtain matrix\u2010assisted laser desorption\/ionization (MALDI) time\u2010of\u2010flight mass spectra using a Nd:YAG\u2010pumped optical parametric oscillator (OPO). The matrices were used to ionize the protein bovine insulin at wavelengths between 2.6 and 4.0\u2005\u03bcm. Protonated insulin was observed between 2.81 and 3.55\u2005\u03bcm with succinic acid, between 2.73 and 3.5\u2005\u03bcm with caffeic acid, and in two distinct bands with 4\u2010nitroaniline: one from 2.85 to 3.1\u2005\u03bcm and another between 3.4 and 3.5\u2005\u03bcm. The best signal and mass resolution were found at approximately 2.9\u2005\u03bcm for all matrices. The minimum laser fluence required for MALDI (threshold fluence) was compared to the IR absorption spectra of the solid matrix. We found a good correlation between IR absorption and inverse threshold fluence for the NH and CH stretch absorption bands of 4\u2010nitroaniline. The threshold fluence was lower than expected between 2.81 and 3.3\u2005\u03bcm for succinic acid and between 2.73 and 2.85\u2005\u03bcm for caffeic acid. The low threshold fluence and good MALDI performance in the 2.9\u2005\u03bcm region can be explained by free OH group or residual water absorption.<\/p>\n<\/div><\/div>\n<\/div><\/div>\n","protected":false},"excerpt":{"rendered":"","protected":false},"author":1,"featured_media":2370,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[131,5],"tags":[8,9],"class_list":["post-2240","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-emory","category-publication","tag-infrared","tag-maldi","entry"],"_links":{"self":[{"href":"https:\/\/kermitmurray.com\/research\/wp-json\/wp\/v2\/posts\/2240","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/kermitmurray.com\/research\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/kermitmurray.com\/research\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/kermitmurray.com\/research\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/kermitmurray.com\/research\/wp-json\/wp\/v2\/comments?post=2240"}],"version-history":[{"count":4,"href":"https:\/\/kermitmurray.com\/research\/wp-json\/wp\/v2\/posts\/2240\/revisions"}],"predecessor-version":[{"id":2371,"href":"https:\/\/kermitmurray.com\/research\/wp-json\/wp\/v2\/posts\/2240\/revisions\/2371"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/kermitmurray.com\/research\/wp-json\/wp\/v2\/media\/2370"}],"wp:attachment":[{"href":"https:\/\/kermitmurray.com\/research\/wp-json\/wp\/v2\/media?parent=2240"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/kermitmurray.com\/research\/wp-json\/wp\/v2\/categories?post=2240"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/kermitmurray.com\/research\/wp-json\/wp\/v2\/tags?post=2240"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}