On the basis of these findings, a modified RP-HPLC gradient
method is proposed. The method is more rapid, optimises
the column selectivity and completely overcomes the interference
of HA. Finally, the validation parameters show that
the proposed method is sensitive, with a high linearity interval
(from 2 to 800 mg kg−1), bias-free (by recovery tests and
comparison with data from the spectrophotometric (White’s)
method) and more precise (repeatability better than 2.5%
and reproducibility better than 3% in the HMF concentration
range between 5 and 140 mg kg−1) than the RP-HPLC
official method.