How to Deal with Overlapping Absorbances in Spectrophotometry?

[thenewbosco]

Just a quick question about technique.

The procedure calls for analysis at a wavelength where the absorbance is a (relative) maximum. Suppose there are one or more interfering species in solution, which also absorb more or less strongly at this same wavelength. How could/should one deal with such a situation of overlapping absorbances?

Thanks for your help.

 

[indoubt]

I think it depends on what you are measuring. If you are sceptical of contaminants then you should make other tests of that sample to be sure of it.

 

[Gokul43201]

Just a quick question about technique.

The procedure calls for analysis at a wavelength where the absorbance is a (relative) maximum. Suppose there are one or more interfering species in solution, which also absorb more or less strongly at this same wavelength. How could/should one deal with such a situation of overlapping absorbances?

Thanks for your help.

Typically, you determine the optimal wavelength from the excitation/absorption spectrum and obtain two emission spectra - one on the system under study and the second on a blank. The preparation of the blank is highly non-trivial, but the idea is that by subtracting the emission spectrum of the blank from that of the given system, you obtain the emission curve for the required species.

The blank may also be used in the selection of a suitable absorbance maximum.