FTIR and UV-Vis
What is FTIR and UV-Vis Spectroscopy?
UV (Ultra-violet) spectrophotometers use visible light to determine the concentration of chemicals in a mixture. FTIR (Fourier-Transform Infrared Spectroscopy) uses infrared light to the same purpose. Atoms and molecules absorb the energy from the light and under-go electronic transitions. Depending on the atomic composition of each compound, each will have its own absorption (or reflection) profile. This profile allows quantitative determination of analytes in a sample. UV-Vis is often used in HPLC for analysis of the separated mixture.
Why do we do it?
Assessing the constituent parts of a finished pharmaceutical product, raw material or API is an essential stage in determining product safety. It is a regulatory requirement defined within every pharmacopoeia that products, both sterile and non-sterile, must be assessed for their chemical quality. As such, each product must have an associated method for chemical analysis which is performed routinely on every batch. UV-Vis can be an appropriate method for identifying an API or excipient. FTIR and UV-Vis are primarily used for identification. You could use UV-Vis in association with other tests e.g. dissolution to determine the amount of drug released in the medium.
How can we help assure compliance?
A spectrophotometer is an instrument that measures the light photons passing through a sample. The sample is pressed into a flat crystalline disc using a diamond tip. This allows photons to readily pass through the sample. As the UV or IR light passes through the sample it is absorbed or reflected depending on the molecules present. The intensity of the light is than measure compared to a calibration curve or standard in order to give a quantitative result. UV is typically monochromatic light where an FTIR uses light of many frequencies. FTIR read-outs require computer processing using a Fourier transformation to obtain the data.
At Honeyman Laboratories, we have experience in the use of UV-Vis and FTIR for the identification and quantitative analysis of finished products, API’s and raw materials. All analysis is performed in accordance with Pharmacopoeial monographs. Bespoke client requirements can also be tailored, contact us now for further information.