Sample Preparation, Butylated Hydroxyanisole - METTLER TOLEDO

Sample Preparation, Butylated Hydroxyanisole

SampleButylated hydroxyanisole

Butylated hydroxyanisole

 

Application

Inactive ingredient (antioxidant)

 

Conditions

Measuring cellDSC820

Pan: Aluminum 40 µl, hermetically sealed

Sample preparation: As received (1) or crystals ground in a mortar (2)

DSC measurement: Heating from 30 °C to 70 °C at 2.5 K/min

Atmosphere: Nitrogen, 50 cm3/min

 

Interpretation

The two curves show the effects that sample preparation can have on the results. In both cases, two melting peaks can be observed that differ noticeably in temperature range and in the heats of fusion. The explanation lies in the polymorphic behavior of butylated hydroxyanisole. The two peaks correspond to the possible crystal modifications.

 

Evaluation

Onset temperature determination and integration of the melting peak of the DSC curve.

Sample preparationOnset 1, °CΔH, J/gOnset 2, °CΔH, J/g
as recieved59.378.263.327.6
ground in a mortar55.196.861.71.7

 

Conclusion

A difference in sample preparation (especially mechanical treatment) can lead to different results. This is particularly the case with substances that exhibit polymorphism.

 

Sample Preparation, Butylated Hydroxyanisole | Thermal Analysis Application No. HB841 | Application published in METTLER TOLEDO TA Application Handbook Pharmaceuticals