Sample Handling:

The UV-VIS absorption spectra are commonly determined either in vapour phase or in solution.  In sequence to take the UV spectrum of the analyte it is taken in a cell known as a cuvette that is transparent to the wavelength of light passing by it. A variety of quartz cuvettes are available for the spectral determination within the vapour phase. These are of varying path lengths and are equipped along with inlet and outlets. For measurements on solutions in the visible region the cuvettes made of glass could also be used.

Therefore, since glass absorbs the ultraviolet radiations, those cannot be used in the UV region. Thus, most of the spectrophotometers employ quartz cuvettes, as these could be used for both visible and UV region. Commonly square cuvettes having internal path length 1.0 cm are used, by cuvettes of much smaller path lengths say of 0.1 mm or 0.05 mm are also available.

Figure: Quartz cuvettes for measurements in solution and in vapour phase