HMF (99%) and formic acid (95%) were acquired from Sigma–
Aldrich (São Paulo, Brazil), and acetonitrile (HPLC grade) was purchased
from EMD (Canada). Ultrapure water (0.055 lS cm1) was
produced by a simplicity UV Milli-Q system from Millipore
(Canada) and it is used for the solutions and mobile phase
preparation