The sample is in flour shape (with known MC). With 2 mg sample, 7 micro liter di-ionized water seemed to be very insufficient. I am suspicious about the results. Is it possible to increase the water amount?
Hello Amir
I think you are talking about DSC (differential scanning calorimetry) of flour sample.
Yes, thermal analysis of flour can be done by DSC and you can increase the moisture content for proper hydration of flour. As you mentioned, it seems that after hydration your sample is like a thick paste, in this case, increase the amount of water for hydration and also give some resting period to your hydrated sample
Dear Anju Boora Khatkar ,
I still cannot acquire a good peak for my samples compared to literature. The ratio of water:flour is 3 to 1, but still gelatinization temperature, onset temperature, and final temp. together with enthalpy value are not satisfactory.
Hello Amir,
In this case, you have to standardise your method first.
It is very common during thermal analysis of some kind of sample. So don't worry and run your experiment with different water flour ratio e.g. you can take this in 2:1 or 1:1 ratio. I hope you gave some resting period to your hydrated sample.
There are several factors which contribute in attaining sharp peak e.g water flour ratio, heating rate, gas flow rate etc.
So, also keep all these pont in consideration. I hope you will get your result by this.
Dear Anju Boora Khatkar ,
The aluminum pans were swelling with increasing in temperature. As the methods indicated on hermetically sealed pans, I think evaporation of water might be the reason I don't get any peak.
Any suggestions?
Dear Amir Amini ,
we used silica crucible for thermal analysis and not faced such type of problem.
Could you please provide the detailed procedure you followed (with temprature profile).I will try to find out the solution for the same.
Dear Anju Boora Khatkar ,
I do appreciate your response. This is the method I've been using:
About 2 mg dried flour were weighed on an aluminium pan and 7 μL of distilled water were added. The pan was sealed tightly and was kept still for 1 h before the analysis. An empty aluminium pan was used as reference. The sample was submitted to a heating program over a range of temperature from 10 to 120 °C at heating rate of 10 °C min-1.
- Badges
- Science topic
- Similar topics
- Chemistry