Thermal methods of analysis

1. THERMAL METHODS OF ANALYSIS

2. Introduction to thermal methods of analysis & Thermo-microscopy Speakers: Rabia Sundus mukhtar

3. Thermal method of analysis: c omprise a group of techniques in which a physical property of a substance is measured as a function of temperature while the substance is subjected to a controlled temperature programme .

4. Classification of thermo-analytical techniques :

5. Techniques most commonly used in pharmacy: Thermo-microscopy 2. Differential thermal analysis 3. Differential scanning calorimetry 4. thermo- gravimetry

6. Thermo-microscopy: Developed by Austrian pharmacognosist  Ludwig Kofler and his wife Adelheid Kofler and continued by Maria Kuhnert-Brandstätter. This technique is also known as hot-stage microscopy.

7. Technique involves the observation of sample through a microscope fitted with a stage that can be heated or cooled at a controlled rate. Modern hot stages can cover the range of -180  to 600C.

8. DIFFERENTIAL THERMAL ANALYSIS Speakers: Anam hassan Bushra khan

9. DEFINITION Differential thermal analysis is the measurement of the difference in temperature between a sample and a reference as heat is applied to the system.

10. DTA GRAPH

11. FACTORS AFFECT RESULT IN DTA Sample weight Heating rate Particle size Atmospheric condition

12. INSTRUMENTATION Apparatus for DTA consists of: Sample & reference holder A furnace A detector An amplifier A recorder

13. APPLICATIONS Qualitative and quantitative identification of minerals. Analysis of biological material To determine M.P, B.P, decomposition temperature of organic compounds. Widely used for the quality control of a large number of substances like cement, glass, soil etc. Also used for the thermal stability of inorganic compounds and complexes.

14. DIFFERENTIAL SCANNING CALORIMETERy SPEAKERS: HIRA ARSHAD AMMARA FAROOQUI

15. TERMS TO KNOW: CALORIMETER DIFFERENTIAL CALORIMETER DIFFERENTIAL SCANNING CALORIMETER Heat the sample with linear temperature ramp

16. PRINCIPLE T he measuring principle is to compare the rate of heat flow to the sample and to an inert material which are heated or cooled at the same rate.

17. DSC GRAPH

18. FACTORS AFFECTING DSC Sample shape Carnoba Wax Polymer Blend Polymorphism of Phenobarbitol

19. Sample Size Other Factors Furnace heating rate Sensitivity of recording mechanism Particle size Nature of sample Thermal conductivity

20. INSTRUMENTATION

21. TYPES OF DSC INSTRUMENTS Power compensation DSC Heat-flux DSC Pt resistance thermocouples Chromel-alumel thermocouples Separate sensors & heaters for the sample & reference Sample & reference are connected by a low-resistance heat flow path separate blocks for sample and reference cells one block for both sample & reference cells

22. APPLICATIONS Qualitative analysis Quantitative analysis Detection of impurities

23. Heat of fusion and extent of crystallinity can also be determined . To study and characterize polymers and their identification

24. Discriminate several commercial polymers in a mixture. Determine melting and boiling points more accurately Determine moisture content (moisture presence causes peaks regarding dehydration ).

25. Use to study phase transition Decomposition of inorganic metals like alloy etc. Physical changes of excepients during storage of dosage form DSC with the support of X-ray diffraction and IR spectroscopy are used as screening technique for the compatibility testing of a drug with excepients.

26. THERMOGRAVIMETRY SPEAKERS: MADIHA AHMED & NOOR- U L- AIN

27. THERMOGRAVIMETRY “…. a technique in which the mass of a substance is measured as a function of temperature, while the substance is subjected to a controlled temperature programme .”

28. THERMOBALANCE DEVICE

29. PARTS OF THERMOBALANCE 3 Essential parts of thermo balance which are as follows : P rogrammable F urnace Microbalance R ecorder

30. PROGRAMMABLE FURNACE : A  furnace  is an enclosed structure used for heating materials to very high temperatures.

31. MICROBALANCE A  microbalance  is capable of making precise measurements of weight of objects of relatively small mass.

32. RECORDER: Recorder is use to record the data in computer in graphical form for further interpretation.

33. TEMPERATURE PROGRAMMER BALANCE CONTROLLER POWER FURNACE TEMP. SAMPLE TEMP. WEIGHT GAS IN GAS-TIGHT ENCLOSURE SAMPLE HEATER INSTRUMENTATION:

34. TGA CURVE: The plot also shows the derivative of the TG curve, or the DTG curve, which is often useful in revealing extra detail, such as the small event around 400°C.