PERKIN ELMER LS-5B LUMINESCENCE SPECTROPHOTOMETER
INSTRUMENT SETTING
1) Turn on the switch which is located at the back of the spectrophotometer.
2) There are two controls located one on each side of the Lower Module, which contains the optical assemblies.
3) The Excitation Slit control knob is located on the left hand side with the Excitation Shutter push-button below it; The Emission Slit control knob is on the right hand side.
· Set the Excitation Slit to 5nm
· Set the Emission Slit to 3nm.
4) The instrument contains separate Excitation and Emission monochromators. The monochromators can be set to any required wavelength within their ranges and either or both can be scanned.
The two monochromators have the following limits:
· Excitation — 230 to 720 nm + zero order
· Emission — 250 to 800 nm + zero order
5) AUTO ZERO the instrument without any cuvette in the sample chamber by closing the shutter (the EXS light on).
6) Press the Auto Zero button, open the shutter (EXS off) and choose the ordinate scaling mode (AUTORANGE, AUTO CONC OR FIXED SCALE).
· Set FIXED SCALE = 0.1
7) Remember that the digital readout should be less than 100 to obtain the entire graph on the chart recorder.
8) To hold the samples use quartz fluorescence cell. Wash it with deionized water, wipe off the excess water from the sides and handle the cell with care.
9) Put the cell with solution in the sample holder and close the shutter.
10) Go to Excitation mode. Fix the excitation at desired range. Then press GO TO. It will be set at the desired range. Then go to Emission mode. Press GO TO. It will be automatically set at the lowest value(250 nm).
· For quinine solution set excitation at 250 nm.
· Repeat this with excitation at 350 nm.
11) To scan the number press >> button and monitor that the numbers scanned are less than 100.
12) Then press Start/Stop. Your graph will start to print in the graphic printer.
13) Repeat the procedure as above. Go to Emission mode. Set the limit at desired range. Press GO TO. It will be fixed at that range. Change the mode to Excitation and press GO TO. It will be automatically set at the lowest value (250 nm).
· For quinine solution set emission at 450 nm.
14) A graph will be automatically printed. Caution: When the graph is printed hold the chart paper with hand. The chart paper goes into the printer for calibration. If you don’t hold it with hand it will crush the paper.