Melting Point Depression of Water, Sugar Solutions - METTLER TOLEDO

Melting Point Depression of Water, Sugar Solutions

Sample

Glucose, lactose and saccharose solutions

 

Application

Inactive ingredient (stabilizer in solutions)

 

Conditions

Measuring cell: DSC821e with IntraCooler

Pan: Aluminum 40 µl, hermetically sealed

Sample preparation: One drop of solution is weighed into the pan using a fine pipette

DSC measurement: Cooling from 20 °C to -60 °C. The solution was then equilibrated for 5 minutes at -60 °C and finally heated at 5 K/min to 25 °C 

Atmosphere: Air, stationary environment, no flow rate

 

Interpretation

The diagram shows the melting peaks of the different solutions. The dissolved substance behaves as an impurity and depresses the melting point of the solvent (water).

 

Evaluation

The onset temperatures of the melting peaks of the solutions and the heats of fusion are determined.

SampleOnset, °CSample weight, mg
Glucose (20 weight %)-7.420.067
Lactose (20 weight %)
-4.414.666
Saccharose (20 weight %)
-4.49.412
Saccharose (10 weight %)-2.613.221
Saccharose (5 weight %)-1.89.715
Saccharose (0.1 weight %)-0.314.495

 

Conclusion

The higher the concentration of added sugar, the lower the onset temperature.

 

Melting Point Depression of Water, Sugar Solutions | Thermal Analysis Application No. HB822 | Application published in METTLER TOLEDO TA Application Handbook Pharmaceuticals