The anomalous steps in apparatus 2 are due to lamp/filter changes.

The anomalous steps in apparatus 2 are due to lamp/filter changes.

Dear Debmalya,

Thanks for your help, but other samples with different dispersion quality (although all of them were homogeneous) resulted in same results.

Dear Hugh J Byrne,

Since I do not have so much information about such spectrometry experiments, I didn't understand what you really meant. Is it refere to apparatus damage or improper servicing by the operator?

Greatly appreciate for your kind response.

Is the same GO sample dispersed in the 2 systems? Need more description of your experiment- solvent, duration, temperature, homogeneity, etc to understand the cause of such variation.

I agree with Dr.Hugh and Dr.Mutesem,apparatus 1 gave acceptable UV-Vis spectrum of graphene oxide solution.Spetrum 2 seems to be irregular  which may be due to damaged of lamp, mirror,monochromator , slit , lenses or detector   of spectrophotometer.

Thank you so much Dr.Alshamsi for your detailed explanation.

I understand the problem, hence I will conduct the test with the fixed apparatus after checking out the above-mentioned items.

The instrument is not necessarily damaged, but may need alignment. As it sweeps through the wavelength range (depending on the instrument) it changes filters (to minimise stray light) detectors (from NIR to visible) and lamps (from visible to UV). These changes can result in abrupt changes in your spectrum.