Dear Keshavarz,

FTIR spectroscopy is generally used to find out the functional groups present in the material. Different trough positions (in % transmittance vs wavenumber plot) represent different functional groups with different vibrations (Stretching or bending vibrations). For more details please visit https://www2.chemistry.msu.edu/faculty/reusch/virttxtjml/spectrpy/InfraRed/irspec1.htm

Regards

It works like this: the software gves you a selection of common materials that might be compatible with your spectrum. From what I see, it is pretty good at it. If you do not know what the individual material denominations mean, consult Wikipedia, they are likely to be there.

However, there might exist many more materials (compounds) that might also be compatible with your spectrum. You see, this kind of "assignments" is unfortunately not at all univocal, not just in IR, but in any spectroscopy.

To delimit the outcome better, you should combine these results with other spectroscopies & analyses and also with you prior knowledge. You probably have a pretty good idea what your material might be and that can help a lot to narrow down the results.

I used a date sheet from the Merk company. I think that it will be useful for you.

following to this question . frankly I want to know more about FTIR,

thanks Mohammad Mahdi Keshavarz for this challenging and interesting question

FRIT is used to find the functional groups, may you can use GC-MS to help you to identify your compounds. see this link which shows the wave-number for each group and based on that you can identify the functional groups in your samples.

https://www.cpp.edu/~psbeauchamp/pdf/spec_ir_nmr_spectra_tables.pdf

Dear Mohammad,

I shall give some brief about the FTIR, how it is utmost useful in the identification of the general materials, specially polymeric materials.

Fourier Transform Infrared (FTIR) Spectroscopy is commonly referred to as FTIR Analysis or FTIR Spectroscopy. This infrared spectroscopy method is used to identify organic, polymeric, and in some cases, inorganic materials. The FTIR test relies on infrared light to scan samples and observe bond properties.

FTIR spectroscopy is generally used to find out the functional groups present in the material. The software gves you a selection of common materials that might be compatible with your spectrum. To know more detail about the specific compound information GC-MS can help you out. By FTIR analysis one can identify compounds and the general type of material being analyzed when there are unknowns. This technique is used to assess the purity of some inorganic samples and is highly reliable for identifying polymer composition.

Samples-

FTIR analyzing samples in variety of forms. Good FTIR testing lab can analyze solid, liquid, powder or thin film samples using the following methods:

· Solids placed on a crystal (ATR- attenuated total reflectance)

· Liquids placed between two sodium chloride plates (Nujol this is another techniques) either we can use ATR of Nujol

· Thin film placed in a cassette

· Powdered sample mixed with potasium bromide and placed in a pellet (KBr pellet)

Enough samples are required to obtain an absorption spectrum. During testing, when infrared radiation is passed through a sample, some radiation is absorbed by the sample and the rest passes through.

The process-

The FTIR Spectrometer generates a graph in the form of absorbance spectra, which shows the unique chemical bonds and the molecular structure of the sample material. This absorption spectrum will have peaks representing components present. These absorbance peaks indicate functional groups (e.g. alkanes, ketones, acid chlorides). Different types of bonds, and thus different functional groups, absorb infrared radiation of different wavelengths. The analytical spectrum can be compared to identify components or to find a “best match” for unknown material using the cataloged spectra for known materials.

Hope it work out for you as well.

Professor(Dr.) Ashish

See this link for more information

https://www.labtesting.com/services/materials-testing/chemical-analysis/ftir-analysis/

Hi;

With FTIR, different functional groups absorb heat at different frequencies. It is dependent upon their structure and a vibrational spectrum can be used to determine the functional groups present in a sample. FTIR can be combined with other analytical techniques to gain more information about the material.

With my best regards

It can only tell you about the functional groups and bonds stretching/stiffness .....it wont be able to predict the exact chemical formulae though .....

Hi

There are pre-defined reference peaks and wave numbers. from that you can match and finalize it.

Best

Dr. Arun

Hi i can help you with this , i have a software for ftir analysis, if you need help, I'm call away.

Iman Moghim hello could you please tell about the software name?

Using References

FTIR alone is seldom sufficient to determine the exact material. What form the material is in - is it a powder, a polymer film? What was the sampling technique?

Also, you can go to https://scifinder.cas.org, make an account if you don't have one, and then click on Substance Identifier, write the name of your compound and click on Search, after that click on the number that is above the box which shows your compound structure, and then click on EXPERIMENTAL SPECTRA , you will see the spectra of HNMR, 13C NMR, IR and so on....So, based on the library you will be able to identify your- unknown or the wave number of the functional groups & bonds - by comparing your figure and the library figures.

Niloofar Mousavipak I'm using OPUS or EFTIR with their libraries. also i have some paper with some information about bound and their wave numbers.