OptiMelt Automated Melting Point System - Stanford Research ...

Chapter 4 Maintenance and Calibration 67Acceptability Test ProcedureStep 1Collect the sample preparation information for the three CRSs included in yourcalibration kit. Look specifically for information on sample pretreatment, dryingprocedures, grinding, capillary tube dimensions, sample loading and rated melting points(Rated MPs).TipThe Rated MP of a CRS is usually the clear point of the substance determined by theCertifications Lab. If a temperature interval (MP Range) is indicated instead of a clearpoint, use its mean as the Rated MP.Starting with the lowest melting point CRS (e.g. Vanillin 83 °C),perform Steps 2-9 for each compound.Step 2Select the proper Analysis Method from the Setup submenu of the Melt Screen, ormanually set the Start temperature 5 °C below the certified clear point of the CRS.Preheat the oven to the selected temperature.Step 3For manual programming, set the ramping rate to 1 °C/min (or your preferred ramp rate)and the Stop temperature 5 °C above the certified clear point of the CRS.Step 4Load three capillaries with a 2–3 mm column of the CRS and insert the tubes into theOptiMelt’s sample slots. Measurements for all three capillaries are carried outsimultaneously.TipTo increase the reproducibility of results, load the capillaries using the same grinding,loading and compacting techniques used for your routine melting point determinations.Use the same column height as used for routine determinations.Step 5Start a melting point determination on the three identical samples.Step 6Using the sample buttons on the touchscreen LCD, record manual entries for thetemperatures corresponding to the onset and clear points during the melt.OptiMelt Automated Melting Point System