Question

why does the measurement of fluorescence data require a more intense source of uv/visible spectroscopy? specific. b) what is the typical source for spectofluorometer? c) for the photomuiltiplier transducer what is the mode off operation used signal to noise?

Answer 1

a) because, at low concentrations the fluorescence intensity will generally be proportional to the concentration of thefluorophore.

Unlike in UV/Visible spectroscopy , standard device independent spectra are not essentially attained. the light source intensity and wavelength charecteristics varies over time during each experiment and between each experiment.

the light intensity from excitation source is a function of wavelength. even, if the intensity of the exciting light is monitered and the response of reference solution or detector may be dependent upon wavelength.

the transmission efficiency of the excitation monochromators is a function of wavelength.

b) The typical light source is a xenon flash lamp , which is becoming more common in fluorescence instruments. the desired excitation wavelength is selected using a monochromator.

c) Photomultiplier transducer are useful for low level light detection because they are low-noise amplifiers. Little additional noise is created as the electron pass through the Photomultiplier transducer. this will generally results in more noise being added to signal.