{"id":10,"date":"2024-04-04T00:39:45","date_gmt":"2024-04-03T21:39:45","guid":{"rendered":"https:\/\/sisu.ut.ee\/lcms_method_validation\/103-different-ways-evaluate-robustness\/"},"modified":"2024-06-20T09:58:00","modified_gmt":"2024-06-20T06:58:00","slug":"103-different-ways-evaluate-robustness","status":"publish","type":"page","link":"https:\/\/sisu.ut.ee\/lcms_method_validation\/103-different-ways-evaluate-robustness\/","title":{"rendered":"10.3 Different ways to evaluate robustness"},"content":{"rendered":"<p>In the lecture 10.1 <a href=\"https:\/\/sisu.ut.ee\/lcms_method_validation\/101-robustness-and-ruggedness-relation-lc-ms-method-development\" target=\"_blank\" rel=\"noopener\">Robustness and ruggedness relation to LC-MS method development<\/a> we saw different LC-MS parameters that influence robustness and ruggedness, as well as what the influence of these parameters. On the basis of this information it is possible to plan changes to the method. As a reminder, there was a list of LC parameters, sample and sample preparation parameters and mass spectrometry parameters.<\/p>\n<p>Because of the very large number of potentially variable parameters it is reasonable to divide assessment of ruggedness into separate parts. A very logical division would be to test ruggedness separately for the sample preparation and for the LC-MS analytical part.<\/p>\n<p>Before starting the investigation of robustness it is crucial to find out\u00a0what are the most important performance characteristics of the method.<\/p>\n<p>For example, if the method\u2019s\u00a0LoQ is very close to the LoQ required by legislation, then the changes in the LoQ value have to be monitored against small changes in the method parameters. The most influential method parameters impacting the LoQ could be MS parameters, mobile phase pH and sample preparation parameters.<\/p>\n<p>The main criteria for choosing parameters are (a) how much a given method parameter can influence the critical characteristic and (b) how likely it is that this parameter will change uncontrollably.<\/p>\n<p>If those parameters are chosen, then we should use one of two options to evaluate the method robustness and ruggedness \u2013 to use the experimental design or the One Factor At a Time approach.<\/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><\/h5>\n<h5 style=\"text-align: center;\">Different ways to evaluate robustness<\/h5>\n<h5 style=\"text-align: center;\"><a href=\"http:\/\/www.uttv.ee\/naita?id=23735\" target=\"_blank\" rel=\"noopener\">http:\/\/www.uttv.ee\/naita?id=23735<\/a><\/h5>\n<h5 style=\"text-align: center;\"><a href=\"https:\/\/www.youtube.com\/watch?v=U1nchnq8TZE&amp;feature=youtu.be\" target=\"_blank\" rel=\"noopener\">https:\/\/www.youtube.com\/watch?v=U1nchnq8TZE&amp;feature=youtu.be<\/a><br>\u00a0<\/h5>\n<h3><span style=\"line-height: 107%;\"><span style=\"color: #2f2f2f;\">Example of the One Factor at the time approach <\/span><\/span><\/h3>\n<p style=\"margin-bottom: .0001pt;\"><span style=\"line-height: normal;\"><span style=\"vertical-align: baseline;\">An Example of how an OFAT can be used is described in the table below. O represents here the optimal<span style=\"color: #2f2f2f;\"> value<\/span>, + and \u2013 are values larger and smaller than the optimal value. All three are chosen by the chemist in charge of the method development. For robustness study we change, as the name suggest, one factor at a time and monitor the response variable \u2013 the retention time \u2013 in our example. The actual experiments need to be performed in random order to prevent a bias on the response variable. After finishing the OFAT the responses can be used to calculate e.g. % deviation from the \u201coptimal response\u201d (experiment 7) and thereby deduct if the factor change has a significant influence on the response. <\/span><\/span><\/p>\n<p style=\"margin-bottom: .0001pt;\">\u00a0<\/p>\n<table class=\"table table-hover\" style=\"border-collapse: collapse;\" border=\"1\" width=\"0\" align=\"center\">\n<thead>\n<tr>\n<th style=\"width: 92.25pt;\" scope=\"col\" width=\"185\">\n<p style=\"margin-bottom: .0001pt; text-align: center; padding: 0cm0cm0cm0cm;\" align=\"center\"><span style=\"line-height: normal;\"><span style=\"vertical-align: baseline;\">Experiments <\/span><\/span><\/p>\n<\/th>\n<th style=\"width: 67.5pt; border-left: none;\" scope=\"col\" width=\"135\">\n<p style=\"margin-bottom: .0001pt; text-align: center; padding: 0cm0cm0cm0cm;\" align=\"center\"><span style=\"line-height: normal;\"><span style=\"vertical-align: baseline;\">Actual<br>experiment order <\/span><\/span><\/p>\n<\/th>\n<th style=\"width: 67.5pt; border-left: none;\" scope=\"col\" width=\"135\">\n<p style=\"margin-bottom: .0001pt; text-align: center; padding: 0cm0cm0cm0cm;\" align=\"center\"><span style=\"line-height: normal;\"><span style=\"vertical-align: baseline;\">A<br>pH <\/span><\/span><\/p>\n<\/th>\n<th style=\"width: 67.5pt; border-left: none;\" scope=\"col\" width=\"135\">\n<p style=\"margin-bottom: .0001pt; text-align: center; padding: 0cm0cm0cm0cm;\" align=\"center\"><span style=\"line-height: normal;\"><span style=\"vertical-align: baseline;\">B<br>Additive conc. <\/span><\/span><\/p>\n<\/th>\n<th style=\"width: 67.5pt; border-left: none;\" scope=\"col\" width=\"135\">\n<p style=\"margin-bottom: .0001pt; text-align: center; padding: 0cm0cm0cm0cm;\" align=\"center\"><span style=\"line-height: normal;\"><span style=\"vertical-align: baseline;\">C<br>Column Temp. <\/span><\/span><\/p>\n<\/th>\n<th style=\"width: 67.5pt; border-left: none;\" scope=\"col\" width=\"135\">\n<p style=\"margin-bottom: .0001pt; text-align: center; padding: 0cm0cm0cm0cm;\" align=\"center\"><span style=\"line-height: normal;\"><span style=\"vertical-align: baseline;\">Response<br>Retention time <\/span><\/span><\/p>\n<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td style=\"width: 92.25pt; border: solidwindowtext1.0pt; border-top: none;\" width=\"185\">\n<p style=\"margin-bottom: .0001pt; text-align: center; padding: 0cm0cm0cm0cm;\" align=\"center\"><span style=\"line-height: normal;\"><span style=\"vertical-align: baseline;\">1 <\/span><\/span><\/p>\n<\/td>\n<td style=\"width: 67.5pt; border-top: none; border-left: none; border-bottom: solidwindowtext1.0pt; border-right: solidwindowtext1.0pt;\" width=\"135\">\n<p style=\"margin-bottom: .0001pt; text-align: center; padding: 0cm0cm0cm0cm;\" align=\"center\"><span style=\"line-height: normal;\"><span style=\"vertical-align: baseline;\">3 <\/span><\/span><\/p>\n<\/td>\n<td style=\"width: 67.5pt; border-top: none; border-left: none; border-bottom: solidwindowtext1.0pt; border-right: solidwindowtext1.0pt;\" width=\"135\">\n<p style=\"margin-bottom: .0001pt; text-align: center; padding: 0cm0cm0cm0cm;\" align=\"center\"><span style=\"line-height: normal;\"><span style=\"vertical-align: baseline;\">O <\/span><\/span><\/p>\n<\/td>\n<td style=\"width: 67.5pt; border-top: none; border-left: none; border-bottom: solidwindowtext1.0pt; border-right: solidwindowtext1.0pt;\" width=\"135\">\n<p style=\"margin-bottom: .0001pt; text-align: center; padding: 0cm0cm0cm0cm;\" align=\"center\"><span style=\"line-height: normal;\"><span style=\"vertical-align: baseline;\">O <\/span><\/span><\/p>\n<\/td>\n<td style=\"width: 67.5pt; border-top: none; border-left: none; border-bottom: solidwindowtext1.0pt; border-right: solidwindowtext1.0pt;\" width=\"135\">\n<p style=\"margin-bottom: .0001pt; text-align: center; padding: 0cm0cm0cm0cm;\" align=\"center\"><span style=\"line-height: normal;\"><span style=\"vertical-align: baseline;\">+ <\/span><\/span><\/p>\n<\/td>\n<td style=\"width: 67.5pt; border-top: none; border-left: none; border-bottom: solidwindowtext1.0pt; border-right: solidwindowtext1.0pt;\" width=\"135\">\n<p style=\"margin-bottom: .0001pt; text-align: center; padding: 0cm0cm0cm0cm;\" align=\"center\"><span style=\"line-height: normal;\"><span style=\"vertical-align: baseline;\">7.95 <\/span><\/span><\/p>\n<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 92.25pt; border: solidwindowtext1.0pt; border-top: none;\" width=\"185\">\n<p style=\"margin-bottom: .0001pt; text-align: center; padding: 0cm0cm0cm0cm;\" align=\"center\"><span style=\"line-height: normal;\"><span style=\"vertical-align: baseline;\">2 <\/span><\/span><\/p>\n<\/td>\n<td style=\"width: 67.5pt; border-top: none; border-left: none; border-bottom: solidwindowtext1.0pt; border-right: solidwindowtext1.0pt;\" width=\"135\">\n<p style=\"margin-bottom: .0001pt; text-align: center; padding: 0cm0cm0cm0cm;\" align=\"center\"><span style=\"line-height: normal;\"><span style=\"vertical-align: baseline;\">6 <\/span><\/span><\/p>\n<\/td>\n<td style=\"width: 67.5pt; border-top: none; border-left: none; border-bottom: solidwindowtext1.0pt; border-right: solidwindowtext1.0pt;\" width=\"135\">\n<p style=\"margin-bottom: .0001pt; text-align: center; padding: 0cm0cm0cm0cm;\" align=\"center\"><span style=\"line-height: normal;\"><span style=\"vertical-align: baseline;\">O <\/span><\/span><\/p>\n<\/td>\n<td style=\"width: 67.5pt; border-top: none; border-left: none; border-bottom: solidwindowtext1.0pt; border-right: solidwindowtext1.0pt;\" width=\"135\">\n<p style=\"margin-bottom: .0001pt; text-align: center; padding: 0cm0cm0cm0cm;\" align=\"center\"><span style=\"line-height: normal;\"><span style=\"vertical-align: baseline;\">O <\/span><\/span><\/p>\n<\/td>\n<td style=\"width: 67.5pt; border-top: none; border-left: none; border-bottom: solidwindowtext1.0pt; border-right: solidwindowtext1.0pt;\" width=\"135\">\n<p style=\"margin-bottom: .0001pt; text-align: center; padding: 0cm0cm0cm0cm;\" align=\"center\"><span style=\"line-height: normal;\"><span style=\"vertical-align: baseline;\">\u2013 <\/span><\/span><\/p>\n<\/td>\n<td style=\"width: 67.5pt; border-top: none; border-left: none; border-bottom: solidwindowtext1.0pt; border-right: solidwindowtext1.0pt;\" width=\"135\">\n<p style=\"margin-bottom: .0001pt; text-align: center; padding: 0cm0cm0cm0cm;\" align=\"center\"><span style=\"line-height: normal;\"><span style=\"vertical-align: baseline;\">8.13 <\/span><\/span><\/p>\n<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 92.25pt; border: solidwindowtext1.0pt; border-top: none;\" width=\"185\">\n<p style=\"margin-bottom: .0001pt; text-align: center; padding: 0cm0cm0cm0cm;\" align=\"center\"><span style=\"line-height: normal;\"><span style=\"vertical-align: baseline;\">3 <\/span><\/span><\/p>\n<\/td>\n<td style=\"width: 67.5pt; border-top: none; border-left: none; border-bottom: solidwindowtext1.0pt; border-right: solidwindowtext1.0pt;\" width=\"135\">\n<p style=\"margin-bottom: .0001pt; text-align: center; padding: 0cm0cm0cm0cm;\" align=\"center\"><span style=\"line-height: normal;\"><span style=\"vertical-align: baseline;\">5 <\/span><\/span><\/p>\n<\/td>\n<td style=\"width: 67.5pt; border-top: none; border-left: none; border-bottom: solidwindowtext1.0pt; border-right: solidwindowtext1.0pt;\" width=\"135\">\n<p style=\"margin-bottom: .0001pt; text-align: center; padding: 0cm0cm0cm0cm;\" align=\"center\"><span style=\"line-height: normal;\"><span style=\"vertical-align: baseline;\">O <\/span><\/span><\/p>\n<\/td>\n<td style=\"width: 67.5pt; border-top: none; border-left: none; border-bottom: solidwindowtext1.0pt; border-right: solidwindowtext1.0pt;\" width=\"135\">\n<p style=\"margin-bottom: .0001pt; text-align: center; padding: 0cm0cm0cm0cm;\" align=\"center\"><span style=\"line-height: normal;\"><span style=\"vertical-align: baseline;\">+ <\/span><\/span><\/p>\n<\/td>\n<td style=\"width: 67.5pt; border-top: none; border-left: none; border-bottom: solidwindowtext1.0pt; border-right: solidwindowtext1.0pt;\" width=\"135\">\n<p style=\"margin-bottom: .0001pt; text-align: center; padding: 0cm0cm0cm0cm;\" align=\"center\"><span style=\"line-height: normal;\"><span style=\"vertical-align: baseline;\">O <\/span><\/span><\/p>\n<\/td>\n<td style=\"width: 67.5pt; border-top: none; border-left: none; border-bottom: solidwindowtext1.0pt; border-right: solidwindowtext1.0pt;\" width=\"135\">\n<p style=\"margin-bottom: .0001pt; text-align: center; padding: 0cm0cm0cm0cm;\" align=\"center\"><span style=\"line-height: normal;\"><span style=\"vertical-align: baseline;\">8.12 <\/span><\/span><\/p>\n<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 92.25pt; border: solidwindowtext1.0pt; border-top: none;\" width=\"185\">\n<p style=\"margin-bottom: .0001pt; text-align: center; padding: 0cm0cm0cm0cm;\" align=\"center\"><span style=\"line-height: normal;\"><span style=\"vertical-align: baseline;\">4 <\/span><\/span><\/p>\n<\/td>\n<td style=\"width: 67.5pt; border-top: none; border-left: none; border-bottom: solidwindowtext1.0pt; border-right: solidwindowtext1.0pt;\" width=\"135\">\n<p style=\"margin-bottom: .0001pt; text-align: center; padding: 0cm0cm0cm0cm;\" align=\"center\"><span style=\"line-height: normal;\"><span style=\"vertical-align: baseline;\">1 <\/span><\/span><\/p>\n<\/td>\n<td style=\"width: 67.5pt; border-top: none; border-left: none; border-bottom: solidwindowtext1.0pt; border-right: solidwindowtext1.0pt;\" width=\"135\">\n<p style=\"margin-bottom: .0001pt; text-align: center; padding: 0cm0cm0cm0cm;\" align=\"center\"><span style=\"line-height: normal;\"><span style=\"vertical-align: baseline;\">O <\/span><\/span><\/p>\n<\/td>\n<td style=\"width: 67.5pt; border-top: none; border-left: none; border-bottom: solidwindowtext1.0pt; border-right: solidwindowtext1.0pt;\" width=\"135\">\n<p style=\"margin-bottom: .0001pt; text-align: center; padding: 0cm0cm0cm0cm;\" align=\"center\"><span style=\"line-height: normal;\"><span style=\"vertical-align: baseline;\">\u2013 <\/span><\/span><\/p>\n<\/td>\n<td style=\"width: 67.5pt; border-top: none; border-left: none; border-bottom: solidwindowtext1.0pt; border-right: solidwindowtext1.0pt;\" width=\"135\">\n<p style=\"margin-bottom: .0001pt; text-align: center; padding: 0cm0cm0cm0cm;\" align=\"center\"><span style=\"line-height: normal;\"><span style=\"vertical-align: baseline;\">O <\/span><\/span><\/p>\n<\/td>\n<td style=\"width: 67.5pt; border-top: none; border-left: none; border-bottom: solidwindowtext1.0pt; border-right: solidwindowtext1.0pt;\" width=\"135\">\n<p style=\"margin-bottom: .0001pt; text-align: center; padding: 0cm0cm0cm0cm;\" align=\"center\"><span style=\"line-height: normal;\"><span style=\"vertical-align: baseline;\">7.72 <\/span><\/span><\/p>\n<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 92.25pt; border: solidwindowtext1.0pt; border-top: none;\" width=\"185\">\n<p style=\"margin-bottom: .0001pt; text-align: center; padding: 0cm0cm0cm0cm;\" align=\"center\"><span style=\"line-height: normal;\"><span style=\"vertical-align: baseline;\">5 <\/span><\/span><\/p>\n<\/td>\n<td style=\"width: 67.5pt; border-top: none; border-left: none; border-bottom: solidwindowtext1.0pt; border-right: solidwindowtext1.0pt;\" width=\"135\">\n<p style=\"margin-bottom: .0001pt; text-align: center; padding: 0cm0cm0cm0cm;\" align=\"center\"><span style=\"line-height: normal;\"><span style=\"vertical-align: baseline;\">4 <\/span><\/span><\/p>\n<\/td>\n<td style=\"width: 67.5pt; border-top: none; border-left: none; border-bottom: solidwindowtext1.0pt; border-right: solidwindowtext1.0pt;\" width=\"135\">\n<p style=\"margin-bottom: .0001pt; text-align: center; padding: 0cm0cm0cm0cm;\" align=\"center\"><span style=\"line-height: normal;\"><span style=\"vertical-align: baseline;\">+ <\/span><\/span><\/p>\n<\/td>\n<td style=\"width: 67.5pt; border-top: none; border-left: none; border-bottom: solidwindowtext1.0pt; border-right: solidwindowtext1.0pt;\" width=\"135\">\n<p style=\"margin-bottom: .0001pt; text-align: center; padding: 0cm0cm0cm0cm;\" align=\"center\"><span style=\"line-height: normal;\"><span style=\"vertical-align: baseline;\">O <\/span><\/span><\/p>\n<\/td>\n<td style=\"width: 67.5pt; border-top: none; border-left: none; border-bottom: solidwindowtext1.0pt; border-right: solidwindowtext1.0pt;\" width=\"135\">\n<p style=\"margin-bottom: .0001pt; text-align: center; padding: 0cm0cm0cm0cm;\" align=\"center\"><span style=\"line-height: normal;\"><span style=\"vertical-align: baseline;\">O <\/span><\/span><\/p>\n<\/td>\n<td style=\"width: 67.5pt; border-top: none; border-left: none; border-bottom: solidwindowtext1.0pt; border-right: solidwindowtext1.0pt;\" width=\"135\">\n<p style=\"margin-bottom: .0001pt; text-align: center; padding: 0cm0cm0cm0cm;\" align=\"center\"><span style=\"line-height: normal;\"><span style=\"vertical-align: baseline;\">8.32 <\/span><\/span><\/p>\n<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 92.25pt; border: solidwindowtext1.0pt; border-top: none;\" width=\"185\">\n<p style=\"margin-bottom: .0001pt; text-align: center; padding: 0cm0cm0cm0cm;\" align=\"center\"><span style=\"line-height: normal;\"><span style=\"vertical-align: baseline;\">6 <\/span><\/span><\/p>\n<\/td>\n<td style=\"width: 67.5pt; border-top: none; border-left: none; border-bottom: solidwindowtext1.0pt; border-right: solidwindowtext1.0pt;\" width=\"135\">\n<p style=\"margin-bottom: .0001pt; text-align: center; padding: 0cm0cm0cm0cm;\" align=\"center\"><span style=\"line-height: normal;\"><span style=\"vertical-align: baseline;\">2 <\/span><\/span><\/p>\n<\/td>\n<td style=\"width: 67.5pt; border-top: none; border-left: none; border-bottom: solidwindowtext1.0pt; border-right: solidwindowtext1.0pt;\" width=\"135\">\n<p style=\"margin-bottom: .0001pt; text-align: center; padding: 0cm0cm0cm0cm;\" align=\"center\"><span style=\"line-height: normal;\"><span style=\"vertical-align: baseline;\">\u2013 <\/span><\/span><\/p>\n<\/td>\n<td style=\"width: 67.5pt; border-top: none; border-left: none; border-bottom: solidwindowtext1.0pt; border-right: solidwindowtext1.0pt;\" width=\"135\">\n<p style=\"margin-bottom: .0001pt; text-align: center; padding: 0cm0cm0cm0cm;\" align=\"center\"><span style=\"line-height: normal;\"><span style=\"vertical-align: baseline;\">O <\/span><\/span><\/p>\n<\/td>\n<td style=\"width: 67.5pt; border-top: none; border-left: none; border-bottom: solidwindowtext1.0pt; border-right: solidwindowtext1.0pt;\" width=\"135\">\n<p style=\"margin-bottom: .0001pt; text-align: center; padding: 0cm0cm0cm0cm;\" align=\"center\"><span style=\"line-height: normal;\"><span style=\"vertical-align: baseline;\">O <\/span><\/span><\/p>\n<\/td>\n<td style=\"width: 67.5pt; border-top: none; border-left: none; border-bottom: solidwindowtext1.0pt; border-right: solidwindowtext1.0pt;\" width=\"135\">\n<p style=\"margin-bottom: .0001pt; text-align: center; padding: 0cm0cm0cm0cm;\" align=\"center\"><span style=\"line-height: normal;\"><span style=\"vertical-align: baseline;\">9.82 <\/span><\/span><\/p>\n<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 92.25pt; border: solidwindowtext1.0pt; border-top: none;\" width=\"185\">\n<p style=\"margin-bottom: .0001pt; text-align: center; padding: 0cm0cm0cm0cm;\" align=\"center\"><span style=\"line-height: normal;\"><span style=\"vertical-align: baseline;\">7 <\/span><\/span><\/p>\n<\/td>\n<td style=\"width: 67.5pt; border-top: none; border-left: none; border-bottom: solidwindowtext1.0pt; border-right: solidwindowtext1.0pt;\" width=\"135\">\n<p style=\"margin-bottom: .0001pt; text-align: center; padding: 0cm0cm0cm0cm;\" align=\"center\"><span style=\"line-height: normal;\"><span style=\"vertical-align: baseline;\">7 <\/span><\/span><\/p>\n<\/td>\n<td style=\"width: 67.5pt; border-top: none; border-left: none; border-bottom: solidwindowtext1.0pt; border-right: solidwindowtext1.0pt;\" width=\"135\">\n<p style=\"margin-bottom: .0001pt; text-align: center; padding: 0cm0cm0cm0cm;\" align=\"center\"><span style=\"line-height: normal;\"><span style=\"vertical-align: baseline;\">O <\/span><\/span><\/p>\n<\/td>\n<td style=\"width: 67.5pt; border-top: none; border-left: none; border-bottom: solidwindowtext1.0pt; border-right: solidwindowtext1.0pt;\" width=\"135\">\n<p style=\"margin-bottom: .0001pt; text-align: center; padding: 0cm0cm0cm0cm;\" align=\"center\"><span style=\"line-height: normal;\"><span style=\"vertical-align: baseline;\">O <\/span><\/span><\/p>\n<\/td>\n<td style=\"width: 67.5pt; border-top: none; border-left: none; border-bottom: solidwindowtext1.0pt; border-right: solidwindowtext1.0pt;\" width=\"135\">\n<p style=\"margin-bottom: .0001pt; text-align: center; padding: 0cm0cm0cm0cm;\" align=\"center\"><span style=\"line-height: normal;\"><span style=\"vertical-align: baseline;\">O <\/span><\/span><\/p>\n<\/td>\n<td style=\"width: 67.5pt; border-top: none; border-left: none; border-bottom: solidwindowtext1.0pt; border-right: solidwindowtext1.0pt;\" width=\"135\">\n<p style=\"margin-bottom: .0001pt; text-align: center; padding: 0cm0cm0cm0cm;\" align=\"center\"><span style=\"line-height: normal;\"><span style=\"vertical-align: baseline;\">8.03 <\/span><\/span><\/p>\n<\/td>\n<\/tr>\n<tr>\n<td style=\"width: 92.25pt; border: solidwindowtext1.0pt; border-top: none;\" colspan=\"6\" width=\"185\"><span style=\"line-height: normal;\"><span style=\"vertical-align: baseline;\">*O Optimal <span style=\"color: #2f2f2f;\">factor<\/span> setting<\/span><\/span><\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p>\u00a0<\/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><br>One Factor at a Time<br><a title=\"\" href=\"https:\/\/www.uttv.ee\/naita?id=32134\" target=\"_blank\" rel=\"noopener\" data-url=\"https:\/\/www.uttv.ee\/naita?id=32134\">https:\/\/www.uttv.ee\/naita?id=32134<\/a><\/h5>\n<h5 style=\"text-align: center;\"><a title=\"\" href=\"https:\/\/youtu.be\/kBR703IK08A\" target=\"_blank\" rel=\"noopener\" data-url=\"https:\/\/youtu.be\/kBR703IK08A\">https:\/\/youtu.be\/kBR703IK08A<\/a><\/h5>\n<p>In most cases experiments with one-by-one variations (One Factor At a Time approach) of the most important parameters are carried out.<\/p>\n<p>Based on the common practice and for the sake of simplicity, we recommend the following if using OFAT:<\/p>\n<ol>\n<li>Change parameters one by one (One Factor At a Time approach) in both directions from the nominal (optimal) value. Changes in the parameters should be realistic in the context of normal use of the method.<\/li>\n<li>\u201cDo not stop there!\u201d Often parameters may be mutually unrelated (uncorrelated), but in some cases this does not hold. For example: change in mobile phase pH can decrease resolution between two adjacent peaks. Likewise, increase of the mobile phase flow rate can also lead to a decrease of resolution. While separately either of these two changes can still lead to insignificant loss of resolution, their occurrence together may lead to peak overlap. Whether this is the case, can often be determined by educated inspection of the effects of the changes (without additional experiments) and noting potential problems.<\/li>\n<li>Effects from the change of parameters should be recorded and if necessary, graphical or statistical analysis of the effects should be done.<\/li>\n<li>Regarding the robustness tests results, if necessary, measures to improve the performance of the method should be taken.<\/li>\n<\/ol>\n<div>\n<div>\n<p>Alternative to OFAT, Design of Experiments (DoE), is\u00a0somewhat less used, especially at routine laboratories, because these approaches require knowledge and experience with mathematical statistics. Furthermore, programming skills in R or Python are beneficial\u00a0if the chemist is not willing to buy a software tool for the evaluation of the experimental designs.\u00a0In this course we will give an overview of both \u2013 One Factor At a Time approach, which we covered here, and the\u00a0<a href=\"https:\/\/sisu.ut.ee\/lcms_method_validation\/104-experimental-design\" target=\"_blank\" rel=\"noopener\">Experimental Design<\/a>\u00a0(DoE) approach. For DoE\u00a0we offer two approaches:<\/p>\n<p style=\"margin-left: 40px;\">1. Shorter introduction in chapter 10.4.<br>2. Longer introduction in chapter 10.5 (this is bonus content, not mandatory to pass the course).<\/p>\n<\/div>\n<\/div>\n<p>\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 id=\"wp-block-file--media-87594715-1df0-4ab3-a423-ecbc82a18d9c\" href=\"https:\/\/sisu.ut.ee\/wp-content\/uploads\/sites\/130\/10.3_different_ways_to_evaluate_robustness.pdf\" target=\"_blank\" rel=\"noreferrer noopener\">10.3_different_ways_to_evaluate_robustness.pdf<\/a><\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":"<p>In the lecture 10.1 Robustness and ruggedness relation to LC-MS method development we saw different LC-MS parameters that influence robustness and ruggedness, as well as what the influence of these parameters. On the basis of this information it is possible &#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-10","page","type-page","status-publish","hentry"],"acf":[],"_links":{"self":[{"href":"https:\/\/sisu.ut.ee\/lcms_method_validation\/wp-json\/wp\/v2\/pages\/10","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=10"}],"version-history":[{"count":3,"href":"https:\/\/sisu.ut.ee\/lcms_method_validation\/wp-json\/wp\/v2\/pages\/10\/revisions"}],"predecessor-version":[{"id":1397,"href":"https:\/\/sisu.ut.ee\/lcms_method_validation\/wp-json\/wp\/v2\/pages\/10\/revisions\/1397"}],"wp:attachment":[{"href":"https:\/\/sisu.ut.ee\/lcms_method_validation\/wp-json\/wp\/v2\/media?parent=10"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}