[shrikantvarma]

can we calculate purity of compound by using infra red spectroscopy?? is standard of compound required for this ??

[jchan123]

I'm sure someone has come up with a clever way to do this.  But in short, the answer is no. 

[orgopete]

While analysis of this type are somewhat unusual, there is nothing inherently different in IR spectroscopy than visible or UV.

You will need to calibrate and create a standard curve for your analysis and this will involve having a pure sample. I would further suggest consider using an internal standard as well. As with any analysis, you need to determine the accuracy of your analysis. If you do not need great precision, you may be able to do this simply. This is virtually what one does in comparing an IR spectrum with an authentic sample. You would take care to check that there are no "extra" peaks in the spectrum that are not in the authentic sample. Those extra peaks are most likely found in the fingerprint region.

The reliability of the analysis will depend on whether you can isolate peaks that will not be interfered with by impurities. Without knowing the analyte and the possible impurities, this may be trivial or nearly impossible. For example, an acetylene or nitrile may be easy to analyze and a substituted benzene derivative with aromatic impurities may be nearly impossible.