If a compound shows two peaks in HPLC will it also show two absorption spectrum?
If you observe two bands by liquid chromatography, that means you have two different compounds. They are separated because of the way they interact with the stationary phase.
On the other hand, spectroscopy takes into account the interaction of light with matter (in this case, the two compounds). Each of these compounds will have a different absorption spectrum, with different bands depending on whether it is UV, visible or IR spectroscopy. However, when taking an absorption spectrum, all the bands of its compounds will be present (some could overlap), so it will have a spectrum with multiple absorption bands.
What kind of spectroscopy are you using?
If you observe two bands by liquid chromatography, that means you have two different compounds. They are separated because of the way they interact with the stationary phase.
On the other hand, spectroscopy takes into account the interaction of light with matter (in this case, the two compounds). Each of these compounds will have a different absorption spectrum, with different bands depending on whether it is UV, visible or IR spectroscopy. However, when taking an absorption spectrum, all the bands of its compounds will be present (some could overlap), so it will have a spectrum with multiple absorption bands.
What kind of spectroscopy are you using?
In addition, spectroscopy allows you to identify your compound due to its unique absorption (or emission) bands. Each compound has rotational, vibrational (IR) or electronic (UV-vis) transitions that are characteristic and allows you to identify it depending on how it interacts with light.
It can also be used as a quantification method if you know the cross section of your compound (by using the Beer-Lambert equation).
Spectral analysis allows the analyst to check for co-eluting peaks. It also allows some verification that the peak in the chromatogram is the peak of interest.
Two peaks mean two compounds so that should have different uv spectrum inless enantiomers.
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