Instrumentation for Fluorescence and Phosphorescence

The four main components of any fluorescence or phosphorescence instrument are the source of excitation, the sample cell, the detector, and the filters or gratings used to select the exciting and emitted radiation. Phosphorescence instruments must also include a Dewar flask for the liquid nitrogen used to freeze samples. Since phosphorescence instruments have the same four main components as fluorescence instruments, the common components of both will be discussed first. 

The usual source employed in filter fluorometers is a 4-watt mercury-arc lamp, either with a clear quartz envelope (emitting primarily 254-nm radiation) or one 

Sample Cells and the Cell Compartment. The sample cell may be made of glass, of optical-grade quartz, or synthetic silica. Glass cells transmit reasonably well down to about 320 nm, depending on the thickness of the cell wall, although there is appreciable absorption below about 360 nm. Ultraviolet grade quartz transmits well down to about 190 nm. 

The cell compartment is painted a dull black and constructed so that any 

7-60 narrow-bandpass filter left) and several sharp-cut filters. The nominal cut-off wavelength for the sharp-cut filters is indicated on each curve. C Several Bausch-and-Lomb interference filters. The bandwidth at half the peak transmittance is given under each peak. From 

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