5. Obtain a sample of commercial tonic water and prepare a diluted sample as above (see demonstrator for dilution factor)
The Perkin-Elmer LS5OB Luminescence spectrometer is an expensive highly sensitive research instrument and under no circumstances should it be operated without proper supervision! The remainder of the procedure must be carried out under guidance from a demonstrator or technician
6. Carefully rinse two cuvettes and fill one with the standard/test solution (sample) and the other with 0.1N sulphuric acid (reference)
7. Carry out measurements of all standards/test solutions with the excitation wavelength setting at 350 nm and the emission wavelength setting at 450 nm, with the appropriate scale expansion for optimum signal/noise ratio.
Plot the fluorescent intensity of each quinine solution against concentration and determine the concentration of the unknown.