{"id":29,"date":"2024-04-04T00:39:47","date_gmt":"2024-04-03T21:39:47","guid":{"rendered":"https:\/\/sisu.ut.ee\/lcms_method_validation\/26-identity-confirmation-ms\/"},"modified":"2024-11-25T17:44:04","modified_gmt":"2024-11-25T15:44:04","slug":"26-identity-confirmation-ms","status":"publish","type":"page","link":"https:\/\/sisu.ut.ee\/lcms_method_validation\/26-identity-confirmation-ms\/","title":{"rendered":"2.6. Identity confirmation by MS"},"content":{"rendered":"<p>For identity confirmation, the MS provides <em>m\/z<\/em> values of ions formed from the analyte molecules and relative abundancies of the ions. Validation guidelines by SANTE\/SANCO [ref 4] and European Commission Implementing Regulation 2021\/808 [ref 5] are the most specific with respect to using MS data for identity confirmation and are recommended by the authors of this course. In the rest of this chapter we rely on these two validation guidelines.<br>For comparison, reference mass spectra should be recorded on the same instrument and using the same operating mode as used for the sample analysis. Preferably, reference spectra should be recorded within the same analysis batch as the\u00a0samples.<br>Recommendations for choosing good diagnostic (characteristic) ions:<\/p>\n<ul>\n<li>The quasimolecular ion\u00a0should be involved in identification.<\/li>\n<li>High <em>m\/z<\/em> (<em>m\/z<\/em> &gt; 100) product ions are more specific than low <em>m\/z<\/em> ions.<\/li>\n<li>Product ions due to common loss (eg H<sub>2<\/sub>O or\u00a0NH<sub>3<\/sub>) are of little diagnostic value.<\/li>\n<li>The choice of diagnostic ions depends on matrix interferences.<\/li>\n<\/ul>\n<p>The usage of principles outlined in this section is illustrated in <a href=\"https:\/\/sisu.ut.ee\/lcms_method_validation\/27-identity-confirmation-examples\/\" target=\"_blank\" rel=\"noopener\">section 2.7<\/a>.<\/p>\n<h5 style=\"text-align: center;\"><div class=\"ratio ratio-16x9 mb-3\"><div class=\"video-placeholder-wrapper video-placeholder-wrapper--16x9\">\n\t\t\t    <div class=\"video-placeholder d-flex justify-content-center align-items-center\">\n\t\t\t        <div class=\"overlay text-white p-2 w-100 text-center d-block justify-content-center align-items-center\">\n\t\t\t            <div>To view third-party content, please accept cookies.<\/div>\n\t\t\t            <button class=\"btn btn-secondary btn-sm mt-1 consent-change\">Change consent<\/button>\n\t\t\t        <\/div>\n\t\t\t    <\/div>\n\t\t\t<\/div>\n<\/div>Identity confirmation by MS<br>NB! Video is based on previous versions of validation guidelines. See slides for updated information.\u00a0\u00a0<\/h5>\n<h5 style=\"text-align: center;\"><a href=\"http:\/\/www.uttv.ee\/naita?id=23688\" target=\"_blank\" rel=\"noopener\">http:\/\/www.uttv.ee\/naita?id=23688<\/a><\/h5>\n<h5 style=\"text-align: center;\"><a href=\"https:\/\/www.youtube.com\/watch?v=G2IISK_yM0s\" target=\"_blank\" rel=\"noopener\">https:\/\/www.youtube.com\/watch?v=G2IISK_yM0s<\/a><\/h5>\n<p style=\"text-align: center;\">\u00a0<\/p>\n<p>The usage of principles outlined in the above video are illustrated in <a href=\"https:\/\/sisu.ut.ee\/lcms_method_validation\/27-identity-confirmation-examples\">section 2.7<\/a>.\u00a0<\/p>\n\n\n<div class=\"wp-block-group attached-files-group is-layout-constrained wp-block-group-is-layout-constrained\">\n<div class=\"wp-block-file\"><a href=\"https:\/\/sisu.ut.ee\/wp-content\/uploads\/sites\/130\/2_6_identity_ms_2024.pdf\" target=\"_blank\" rel=\"noreferrer noopener\">2_6_identity_ms.pdf<\/a><\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>For identity confirmation, the MS provides m\/z values of ions formed from the analyte molecules and relative abundancies of the ions. Validation guidelines by SANTE\/SANCO [ref 4] and European Commission Implementing Regulation 2021\/808 [ref 5] are the most specific with &#8230;<\/p>\n","protected":false},"author":60,"featured_media":0,"parent":0,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_acf_changed":false,"inline_featured_image":false,"footnotes":""},"class_list":["post-29","page","type-page","status-publish","hentry"],"acf":[],"_links":{"self":[{"href":"https:\/\/sisu.ut.ee\/lcms_method_validation\/wp-json\/wp\/v2\/pages\/29","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/sisu.ut.ee\/lcms_method_validation\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/sisu.ut.ee\/lcms_method_validation\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/sisu.ut.ee\/lcms_method_validation\/wp-json\/wp\/v2\/users\/60"}],"replies":[{"embeddable":true,"href":"https:\/\/sisu.ut.ee\/lcms_method_validation\/wp-json\/wp\/v2\/comments?post=29"}],"version-history":[{"count":6,"href":"https:\/\/sisu.ut.ee\/lcms_method_validation\/wp-json\/wp\/v2\/pages\/29\/revisions"}],"predecessor-version":[{"id":1505,"href":"https:\/\/sisu.ut.ee\/lcms_method_validation\/wp-json\/wp\/v2\/pages\/29\/revisions\/1505"}],"wp:attachment":[{"href":"https:\/\/sisu.ut.ee\/lcms_method_validation\/wp-json\/wp\/v2\/media?parent=29"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}