Calibration of FTIR
The principle of Fourier-transform infrared spectroscopy (FTIR) is a technique used to attain an infrared spectrum of absorption of a substance (solid, liquid, or gas) the technology simultaneously collects high-spectral-resolution data over a wide spectral range. This confers a significant advantage over a dispersive spectrometer, which measures intensity over a narrow range of wavelengths at a time. The working principle and calibration of FTIR are demonstrated here in this article.
The spectroscopy, where an interference wave is synthesized from two beams separated by a beam splitter, the resulting detected interference waveform (interferogram) is Fourier-transformed, and a spectrum is obtained by separating each wavenumber.
SOP FOR FTIR
1.Objective: To lay down a procedure for Operation of FTIR (8400S) SHIMADZU
2. Scope: The procedure of this SOP shall be applicable to Q.C. Department of XYZ Pharma company
3. Responsibility: Quality Control Chemist
4. Accountability: Quality Control Manager
5. Abbreviations:
S.O.P. : Standard Operating Procedure
QC : Quality Control
QA : Quality Assurance
6. Procedure :
1.) Login to the computer using your NetID and password.
2) Turn on the FTIR machine (the power button is in the front)
3.) Start IRSolution software. Start -> All Programs -> IRSolution
4.) A window may pop up asking to remove marked data. Click yes.
5.) Another window may pop up saying “Auto adjust required. Perform auto adjust now?” Click yes. a. This may take several minutes
6.) On the top toolbar, click on Measurement -> EasyScan
a. A window will pop up with some options. Typically nothing needs to be adjusted, but you can select the range of wavenumbers scanned (in cm-1).
b. Name the data file and add any comments. Then click ok.
7). It will ask to execute BKG (background) measurement. Click yes.
8). It will ask to execute the BKG measurement again. Click no.
9). Now it is time to place the sample in front of the beam. There is a round sample holder that can be used. The tape can also be used to hold the sample in front of the beam. (The beam is red; make sure it is going through the part you want to test).
10). Once the sample is in place, close the chamber and click ok. a. The spectrum will be acquired
11). It will ask “Are you all right?” Click ok.
12). Save the XPS file if desired. It contains the spectrum and lists peaks in a table.
13). Now, you can export the data to a text file for use in Excel or other software if
a. File -> Export. Save as (ASCII) which will make a .txt file.
14). See the figure below to see what the screen should look like.
ftir-graph
15). A peak or spectrum search can now be performed by clicking on search. a. It is recommended to try both as one may find a better match than the other.
16). The Y-Axis can be changed to absorbance or % transmission by clicking Graph -> Y-axis mode -> Tra or Abs
17). The blue – red = green button (circled in the image below) will put both the acquired spectrum and the matched spectrum on the same graph.
18). The matched spectra will be given a score out of 1000 on how well it matches the acquired spectra (922 for this test).
ftir-graph-2
19). When finished a. Close the software
b. Remove the sample
c. Turn off the power
d. Log off
Recommended Distribution:
S.N Department Distribution 1Quality control Yes 2 sop-distribution
Find the calibration method and SOP for some other instruments:
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