{"id":34,"date":"2024-04-04T00:39:47","date_gmt":"2024-04-03T21:39:47","guid":{"rendered":"https:\/\/sisu.ut.ee\/lcms_method_validation\/33-estimating-linear-range\/"},"modified":"2024-04-04T00:41:46","modified_gmt":"2024-04-03T21:41:46","slug":"33-estimating-linear-range","status":"publish","type":"page","link":"https:\/\/sisu.ut.ee\/lcms_method_validation\/33-estimating-linear-range\/","title":{"rendered":"3.3. Estimating the linear range"},"content":{"rendered":"<p>\n\t\u00a0\n<\/p>\n<h5 style=\"text-align: center\">\n\t<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>Linear range, different ranges\u00a0<br>\n<\/h5>\n<h5 style=\"text-align: center\">\n\t<a href=\"http:\/\/www.uttv.ee\/naita?id=23250%20\" style=\"font-family: inherit\" target=\"_blank\" rel=\"noopener\">http:\/\/www.uttv.ee\/naita?id=23250\u00a0<\/a><br>\n<\/h5>\n<h5 style=\"text-align: center\">\n\t<a href=\"https:\/\/www.youtube.com\/watch?v=uc6ZqIKC-Qc\" target=\"_blank\" rel=\"noopener\">https:\/\/www.youtube.com\/watch?v=uc6ZqIKC-Qc\u00a0<\/a><br>\n<\/h5>\n<h5 style=\"text-align: center\">\n\t\u00a0<br>\n<\/h5>\n<p>\n\t<strong>Dynamic range<\/strong> \u2013 In the dynamic range, the response changes when the analyte concentration is changed but the relationship may be non-linear. If a response is linear, it can be specified as a dynamic linear range.\u00a0<a href=\"#\" data-bs-toggle=\"modal\" data-bs-target=\"#popup-modal\" data-title=\"(1)\" data-content='(1) &lt;a href=\"http:\/\/goldbook.iupac.org\/D01874.html\" target=\"_blank\" rel=\"noopener\"&gt;http:\/\/goldbook.iupac.org\/D01874.html&lt;\/a&gt;'>(1)<\/a>\n<\/p>\n<p>\n\t<strong>Working range<\/strong> \u2013 The working range is the range where the method gives results with an\u00a0acceptable uncertainty. A working range can be wider than a linear range. [ref 3]\n<\/p>\n<p>\n\tThis means that there is a correlation between the analyte concentration and the instrument\u2019s signal and\u00a0concentrations of the\u00a0analyte can be determined within this range \u2013 from LoQ to anomalies of the sensitivity.\n<\/p>\n<p>\n\t<strong>Calibration range<\/strong> \u2013 The calibration range is the interval between the upper and the lower concentration of the\u00a0analyte which can be determined with the demonstrated precision, accuracy and response function. \u00a0[ref 7]\n<\/p>\n<p>\n\t<strong>Linear range or linear dynamic range<\/strong> \u2013 The\u00a0<span id=\"docs-internal-guid-426ce40a-a518-5d88-3188-08c19528a6e1\">range of concentrations where the signals are directly proportional to the concentration of the analyte in the sample.<\/span>\n<\/p>\n<p>\n\t<img loading=\"lazy\" decoding=\"async\" width=\"696\" height=\"503\" class=\"alignnone wp-image-371\" style=\"margin-right: auto;margin-left: auto\" src=\"https:\/\/sisu.ut.ee\/wp-content\/uploads\/sites\/130\/3-3-fig1_uus.png\" title=\"3-3-fig1_uus.png\" alt=\"3-3-fig1_uus.png\" srcset=\"https:\/\/sisu.ut.ee\/wp-content\/uploads\/sites\/130\/3-3-fig1_uus.png 696w, https:\/\/sisu.ut.ee\/wp-content\/uploads\/sites\/130\/3-3-fig1_uus-300x217.png 300w\" sizes=\"auto, (max-width: 696px) 100vw, 696px\">\n<\/p>\n<h4 style=\"text-align: center\">\n\tFigure 1. Different ranges<br>\u00a0<br>\n<\/h4>\n<p>\n\tLinearity should be confirmed for the expected working range, including the chosen matrix. A linear range can be found from the linearity assessment experiments, however, the criteria for a\u00a0linear range can be different. A linear range should cover 0\u2013150% or 50\u2013150% of the expected analyte concentration.\n<\/p>\n<p>\n\tWhile a\u00a0linear range for the LC\u2013MS instruments is usually fairly narrow (and depends on the compound), several possibilities have been used in order to widen a linear range. Using the isotopically labeled internal standard (ILIS) is one of them. While the signal-concentration dependence of the compound and an ILIS may not be linear, the ratio of the signals may be linearly dependent on the analyte concentration. But even then, care has to be taken when working outside of a linear range of the signals.\u00a0\n<\/p>\n<p>\n\tOne\u00a0way of\u00a0increasing\u00a0a linear range is by working at the lower concentrations (and diluting samples), if the analyte signal is intense enough. Another way to increase a linear range, specifically in the case of a LC-ESI-MS, is to decrease the charge competition by lowering the flow rate in the ESI source, e.g. by using a\u00a0nano-ESI.\n<\/p>\n<p>\n\t***\n<\/p>\n<p>\n\t(1)\u00a0<a data-url=\"http:\/\/goldbook.iupac.org\/D01874.html\" href=\"http:\/\/goldbook.iupac.org\/D01874.html\" target=\"_blank\" rel=\"noopener\">http:\/\/goldbook.iupac.org\/D01874.html<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"<p>\u00a0 To view third-party content, please accept cookies. Change consent Linear range, different ranges\u00a0 http:\/\/www.uttv.ee\/naita?id=23250\u00a0 https:\/\/www.youtube.com\/watch?v=uc6ZqIKC-Qc\u00a0 \u00a0 Dynamic range \u2013 In the dynamic range, the response changes when the analyte concentration is changed but the relationship may be non-linear. If &#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-34","page","type-page","status-publish","hentry"],"acf":[],"_links":{"self":[{"href":"https:\/\/sisu.ut.ee\/lcms_method_validation\/wp-json\/wp\/v2\/pages\/34","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=34"}],"version-history":[{"count":1,"href":"https:\/\/sisu.ut.ee\/lcms_method_validation\/wp-json\/wp\/v2\/pages\/34\/revisions"}],"predecessor-version":[{"id":850,"href":"https:\/\/sisu.ut.ee\/lcms_method_validation\/wp-json\/wp\/v2\/pages\/34\/revisions\/850"}],"wp:attachment":[{"href":"https:\/\/sisu.ut.ee\/lcms_method_validation\/wp-json\/wp\/v2\/media?parent=34"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}