A new method using Hydrophilic Interaction Liquid Chromatography and UV detection was developed
for the determination of free quinic acid in fourteen commercial beverages (fruit juices, red wine, coffee,
vinegar, and edible mushroom extract). Samples were directly injected into the HPLC system after
dilution and centrifugation. All separations were carried out by gradient elution on a ZIC1-cHILIC
column, using an eluent consisting of acetonitrile and aqueous phosphate buffer at pH 6. Quinic acid
eluted in 12 min as a symmetric peak well separated from all other peaks in the chromatograms. The
total turnaround time per sample was 60 min. The method was validated using cranberry juice as model
beverage matrix. Linearity was demonstrated on spiked juice between 200 and 600 mg/mL (r2 = 0.999),
and precision and accuracy were satisfactory (RSD 10% and recovery 100 1%, respectively).
The method was proven to be suitable for its purpose. Quinic acid levels ranged from undetectable
(