Authors:Bernd Spangenberg and Marion Weyandt-Spangenberg
A new formula is presented for transforming fluorescence measurements in accordance with
theory. The fluorescence signals, the absorption signals, and data from a selected reference are combined in one expression. Only diode-array techniques can measure all the required data simultaneously to linearize fluorescence data correctly. To prove the new theory HPTLC quantification of the analgesic flupirtine was performed over the mass range 300 to 5000 ng per spot. The fluorescence calibration curve was linear over the whole range. The transformation of fluorescence measurements into linear mass-dependent data extends the technique of in-situ fluorescence analysis to the high concentration range. It also extends
theory from absorption to fluorescence analysis. The results presented also emphasize the importance of
theory for in-situ measurements in scattering media, especially in planar chromatography.