NEXTREAT Laboratories performs GLP compliant melting point determination according to OECD 102 and OPPTS 830.7200, based on either one of these methods:
- Differential scanning calorimetry (DSC)
- Capillary melting point determination
By DSC measurement, the temperature or temperature range of the phase transition from the solid to the liquid state is determined using the differential scanning calorimetry method. A small amount of the test item is inserted into the furnace of the device and the transition point is determined based on measuring the heat flow while raised the temperature. The heat flow in and out of a sample and a reference is measured as a function of temperature as the sample is heated. When the sample undergoes a phase transition, the corresponding change of enthalpy gives a departure from the base line of the heat flow record. The difference in energy input necessary to maintain identical temperatures between the substance and the reference is recorded. The measurement signal is the energy absorbed or released by the sample.
For REACH regulatory purposes, the exact determination of the melting point does not need to be conducted, if the melting point is below -20°C.
Exemplary results of DSC measurements
Applicable guidelines:
- Organisation for Economic Co-operation and Development (OECD), Guidelines for the Testing of Chemicals, Guideline No. 102, “Melting Point / Melting Range”, adopted July 27, 1995
- US. EPA Product Properties Test Guidelines OPPTS 830.7200 “Melting Point/Melting Range” of March 1998