{"id":75571,"date":"2024-05-16T16:47:00","date_gmt":"2024-05-16T16:47:00","guid":{"rendered":"https:\/\/discover.restek.com\/?p=75571"},"modified":"2026-01-23T21:14:52","modified_gmt":"2026-01-23T21:14:52","slug":"introducing-the-comprehensive-calibration-calculator","status":"publish","type":"post","link":"https:\/\/discover.restek.com\/de\/blogs-de\/introducing-the-comprehensive-calibration-calculator\/","title":{"rendered":"Introducing the Comprehensive Calibration Calculator"},"content":{"rendered":"\n

Author’s Note:<\/strong> I’ve since updated the spreadsheet to address forcing through zero. Please see the new blog post with updated spreadsheet here<\/a>.<\/em><\/p>\n\n\n\n

Recently Colton Myers has released a standard calculation\u00a0spreadsheet to<\/a>\u00a0pair with our\u00a0calibration blog series<\/a>. I didn\u2019t want to be left out, so here I am introducing a spreadsheet that has almost everything you\u2019ll need to calculate a good calibration. I can\u2019t take full credit for this, as the initial form of the calculator came from the Arizona Department of Health Services (original link<\/a>). From there, I managed to fix some of the weighted quadratic fit issues that were originally present in the sheet and added some extra calculations for %RSE and residual error. Also, Colton managed to figure out some Excel wizardry with cell references to make it much more user friendly. You can find the Restek version of this spreadsheet\u00a0here<\/a>. The spreadsheet was updated on 7\/3\/24 to correct a calculation error.<\/p>\n\n\n\n

Despite all the work we\u2019ve put into this, there are still some limitations to it. First, I haven\u2019t set up any force through zero fits yet, though I hope to add that in the future. The original spreadsheet has those as an option if you need them, though be aware that the weighted quadric fits in the Arizona Department of Health Services version don\u2019t seem to match what I get from MSD Chemstation. Also, I can\u2019t get the r2<\/sup> values for weighted quadratic fits to match MSD Chemstation, though the fits themselves agree. However, I don\u2019t see this as a big problem, since per my previous blog<\/a>, there are better metrics to use for evaluating calibration curves.<\/p>\n\n\n\n

Instructions are on the first tab of the spreadsheet, but with the work that Colton did it\u2019s very easy to use. Simply paste your compound names and responses into the Cal Data tab, which supports up to 200 compounds. There are other fields there for data file info and retention times, but they\u2019re not needed for the spreadsheet to work, they are included to help with traceability. Next, at the bottom of the Cal Data Formatted tab, add in your calibration concentrations. After that, make as many copies of either the ISTD or ESTD template tabs (for internal and external standard calibrations respectively) as you have compounds. On each tab enter the name of your compound and internal standard (if applicable) exactly as they are entered in the Cal Data tab. By default, it\u2019s set up for 10 calibration levels, but if you have less just delete the rows below your last cal level. If everything has been entered correctly the spreadsheet will give you equal weighted, 1\/x, and 1\/x2<\/sup> fits for linear and quadratic regressions, as well as average RF, with associated r2<\/sup>, %RSE, and residual error data. Test data is initially present for compounds 99 and 100 as an example.<\/p>\n\n\n