How to calculate chlorophyll concentration from fluorescence?
Answers
Answer:
To obtain concentrations from fluorescence spectra, the fluorescence quantum efficiency as a function of wavelength of the emitting species has to be known, as well as the total absorbed light. Besides, unless you measure the total emitted light, a calibration of the geometrical distribution of the emitted light is required. The details may be read in a classical books on fluorescence like Principles of fluorescence spectroscopy by J.R.Lakowicz.
However, if small concentrations and emissions are measured, from the equation
IF= FIF I0 (1-10^(-eps.c.l)
where FIF : fluorescence quantum efficiency at a given wavelength;,IF: fluorescence intensity;I0: incident light intensity; eps: molar absorption coefficient at a given wavelength; c: molar concentration; l: optical path length of the cell,
a lineal dependence of IFwith c may be obtained. In fact, for small c values
and you may construct a calibration curve from the spectra of solutions of known (low) concentrations. If a straight line through the origin is obtained, you have chosen the conditions rightly!
Answer:
To obtain concentrations from fluorescence spectra, the fluorescence quantum efficiency as a function of wavelength of the emitting species has to be known, as well as the total absorbed light. Besides, unless you measure the total emitted light, a calibration of the geometrical distribution of the emitted light is required. The details may be read in a classical books on fluorescence like Principles of fluorescence spectroscopy by J.R.Lakowicz.
However, if small concentrations and emissions are measured, from the equation
IF= FIF I0 (1-10^(-eps.c.l)
where FIF : fluorescence quantum efficiency at a given wavelength;,IF: fluorescence intensity;I0: incident light intensity; eps: molar absorption coefficient at a given wavelength; c: molar concentration; l: optical path length of the cell,
a lineal dependence of IFwith c may be obtained. In fact, for small c values
and you may construct a calibration curve from the spectra of solutions of known (low) concentrations. If a straight line through the origin is obtained, you have chosen the conditions rightly!