The observable effects of temperature in chemistry are well-known and well-studied. Changes of state, such as phase transitions (e.g., melting, boiling), decomposition, loss of volatiles, etc., can be used by scientists to assess the identity and purity of a substance. Robertson Microlit Laboratories has developed an expertise in this area, and has been providing thermal analytical services for our clients for over 15 years.

What is Thermogravimetric Analysis?

Simply put, Thermogravimetric Analysis – or TGA – is an analytical technique that precisely measures the effects of temperature on the mass of a substance.

TGA is one technique in RML’s arsenal of analytical tools used for materials characterization. TGA applications can assist in product development, product investigation, and quality control for various industries, including pharmaceutical, food, petrochemical, and environmental.

How does TGA work?

In practical operation, the sample or substance is placed in a sample pan, which is then suspended from an ultra-micro balance in the TGA instrument. The sample pan is then enclosed in a furnace, purged with the desired gas (inert or oxidizing), and heated according to our customers’ specifications, up to 1000°C. As the sample is heated, the ultra-micro balance detects and records any changes in the mass of the sample. Because of the sensitivity and precision of the TGA balance, reliable results can be obtained with very small sample weights (approximately 3 – 20 mg).

Heating of the sample is a very precise and customizable process. The TGA furnace can provide heating at stepped temperature intervals, gradually over a linear temperature gradient, or at a fixed temperature.

What can TGA tell us?

TGA reveals how the mass of a substance is affected by temperature. The information provided by TGA is used by our clients to quantify purity, loss of water, loss of solvent, loss of plasticizer, decarboxylation, pyrolysis, oxidation, decomposition, weight% filler, amount of metallic catalytic residue remaining on carbon nanotubes, and weight % ash. The loss of surface-absorbed solvent can even be distinguished from solvent inclusion in the sample’s crystal lattice.

TGA can also provide measurements that can help to examine potential interactions between drug substances, drug substances and formulation excipients or components, and between drug products and packaging materials.

Our clients can interact directly with RML scientists to discuss specific concerns or to design a TGA experiment to suit their unique needs. Contact us with any questions about TGA analysis, or click here for our Thermal Analysis Request form.

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