The validated assay was applied for determination of EGCG in
tablet formulations as described above. Determination of caffeine
was carried out in order to monitor the efficiency of the decaffeination
step employed. Results showed that the concentration of caffeine
in the processed tablet extracts was always below the LOQ of
the proposed assay for caffeine (Table 3). These results confirmed
that caffeine concentration is less than 0.20 lg/band, corresponding
to 10.0 lg/mL in decaffeinated extract.