Abstract:

An ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method was developed
for the qualitative and quantitative determination of eight saccharides including rhamnose, xylose, arabinose, fructose,
mannose, glucose, sucrose, and raffinose in teas. Samples were extracted with the assistance of ultrasound. The extract was
separated on a Waters Acquity BEH Aminde HPLC column (2.1 mm × 150 mm, 1.7 μm) using acetonitrile-water mixture
(each containing 0.1% ammonia) as the mobile phase. The electrospray ionization tandem quadrupole mass spectrometric
analysis was carried out in the negative ion mode using multiple reaction monitoring (MRM). The limits of detection were
0.01–0.54 mg/L and the linear ranges were 1.0–200.0 mg/L. The average recoveries were 80.2%–103.2% at spiked levels of
10.0 and 100.0 mg/L. The method was applied to analyze 20 tea samples including green tea, oolong tea, Pu’er tea and black
tea. Glucose, fructose, sucrose and raffinose were detected in most of the samples, and their contents were in the ranges of
0.39–17.64, 0.53–22.83, 2.07–40.70, and 0.57–14.67 g/kg, respectively. However, rhamnose, xylose, arabinose and mannose
were not detected in all the samples.

Key words: ultra performance liquid chromatography tandem mass spectrometry, tea, glucose, fructose, sucrose, raffinose