The recovery was used to evaluate the
accuracy of the method. Known amounts of standards were added
to certain amount (0.100 g) of the olive tree bark. The mixture was
extracted and analyzed using the method described above. Three
replicates were performed for the test. Recovery (R) was calculated
as R = 100 (Cfound − Cinitial)/Cadded (Cfound = measured concentration
in the fortified sample, Cinitial = initial concentration in the sample,
Cadded = concentration in the standard solution used) for each
compound. Retention time repeatability was checked with six successive
runs of the olive extracts. Blank sample (pure solvent) was
analyzed to check the occurrence of any impurity or co-elution with
the same m/z as that of the analyte