Sampling:

The priority of fluorescence measurements of the analyte are carried out within solution. For this the sample is taken within a cuvette or in a flow cell. The cuvettes commonly are circular, or square shaped. These are constructed of a material which will transmit both the incident as well as the emitted light. Glass and quartz both qualify this criterion. Therefore, the quartz cuvettes are commonly used while the radiation belongs to the UV region. The square cuvettes are most general and are found to be quite precise as the parameters of a square cuvette are simpler to manage during manufacture. Instead the circular cuvettes though not quite accurate are appropriate for routine applications and have the advantage of being less expensive.

The cuvette or cell is placed general to the incident beam as display in Figure. By resulting fluorescence is provided off equally in all directions, it is collected from the right angles to the incident beam. As fluorimetry is an extremely sensitive method, the following precautions should be followed without exception although handling the cuvettes.