It is confirm

What does the legend means (470 solid, 600 solid, 470 in DMF)? What is the excitation wavelength? Can you please show us the absorption spectra?

Not enough information was given however i am wondering about the blue emission spectra !?!

The numbers are various excitation wavelengths in solid andin DMF.

You mean when you excite at 470 nm you see emission at 451 nm (and 466 nm) and when you excite at 600 nm the emission is at 582 nm?

As per your legend, how can the emission wavelengths be shorter than the excitation wavelength until and unless the instrumental settings are off? In rare cases, monochromators can be off. As suggested above, run a quick scan of the absorption spectrum on UV-VIS spectrometer first.

Thanks M. Farooq Wahab . I also doubt the instrument settings. Can you please suggest the setting? what should be the slit width?

Akrema Aki The best approach when you doubt an instrument is to repeat a standard. Slit widths are secondary at this moment since what you posted does not make a physical sense. Excitation wavelengths < Emission wavelengths in general. You see an opposite trend.

i) Take pure water and choose an excitation wavelength of 250 nm. Run an emission spectrum from 200 nm to 600 nm. What do you see?

ii) Choose another excitation wavelength of 400 nm and repeat (i) with the same emission settings. What do you see?

In the emission spectra (i) and (ii) you should see one Rayleigh peak at = 250 or 400 nm exactly and upon close inspection you should see another small Raman peak of water in each case. If this is true, your excitation and emission monochromators are fine.

iii) Can you run 20-50 ppm quinine sulfate solution in 0.1 M H2SO4? Collect the spectra and compare with a standard.

Dear M. Farooq Wahab

Can you please tell the procedure for solid state? It always come above 1000. and no peak is observed. How to use filters?

Please post results with water emission spectrum from the instrument in standard format. Fill a cuvet with water and collect the emission spectra using 250 nm and 400 nm (see previous post). You should consult the laboratory incharge for he/she should know the instrument's hardware. Before you collect solid spectra, ask the in-charge to run water samples as suggested previously just to check the monochromator calibration.