Abstract:

The aim of this study was to establish a method for the simultaneous determination of polyphenolic compounds
including neochlorogenic acid, chlorogenic acid, cryptochlorogenic acid, cynarin, 1,5-dicaffeoylquinic acid, isochlorogenic
acid B, isochlorogenic acid A, isochlorogenic acid C and alkaloidal compounds including caffeine and trigonelline in
coffee and coffee-based products. These 10 components were extracted ultrasonically with 0.10% phosphoric acid solutionmethanol
(50:50, V/V) and then analyzed by high performance eliquid chromatography (HPLC) at 254 nm and 320 nm. The
chromatographic separation was performed on a Shiseido CAPCELL PAK MGⅡC18（4.6 mm × 250 mm, 5.0 μm） by
using 0.10% phosphoric acid solution-methanol as the mobile phase. The average recoveries of the 10 analytes in spiked
samples ranged from 80.00% to 113.8%, with relative standard deviations (RSDs) of 3.63%–9.10%. The calibration curves
for these analytes were linear in the range of 0.10–100.0 mg/L with correlation coefficients of more than 0.999. The limits
of detection (LODs) varied from 0.05 to 1.0 mg/kg and the limits of quantitation (LOQ) ranged from 0.16 to 0.28 mg/kg for
10 polyphenolic and alkaloidal components. The method showed good repeatability, accuracy and stability and enabled the
accurate quantification of 10 polyphenolic and alkaloidal components in coffee and coffee-based products.

Key words: HPLC, double UV wavelengths, coffee and coffee-based products, polyphenolic compounds, alkaloidal compounds