Determination of 35 Free Amino Acids in Tea Using Ultra-Performance Liquid Chromatography Coupled With Quadrupole Time-of-Flight Mass Spectrometry

Abstract

The purpose of this research was to develop a simple, sensitive, and accurate method for simultaneous determination of 35 free amino acids using ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF/MS). Tea samples were extracted with boiling water bath, and then separated by XBridge BEH Amide column by gradient elution. The exact mass and MS/MS spectra of the target compound was detected under the TOF–MS and Information dependent acquisition (IDA)–MS/MS mode. The results demonstrated good linearity (R2 > 0.9980) in the range of 0.5–1,000 ng/mL. The limits of detection (LODs) were 0.13–25.00 mg/kg and the limits of quantitation (LOQs) were 0.25–50.00 mg/kg. The recovery rate ranged from 70.1 to 105.1% with relative standard deviations (RSDs) <11% (n = 6). This research provides a targeted strategy for developing an analysis method for amino acids in tea.

Discriminative Chemical Profiles of Shan Tuyet Tea (Camellia sinensis var. Shan) and Sinensis Tea (Camellia sinensis var. sinensis) Collected in Ta Xua, Son La, Vietnam and Their Correlation With Antioxidant Activity

“…18-20 In contrast, even though Arg was found in the highest concentration in Shan Tuyet young leaves in this study with 86.1 ± 9.6 µM, corresponding to 0.15 ± 0.02 mg/g d.w., this amino acid represented a lower content than in other C sinensis leaves reported in other studies. 12,19 Orn, an amino acid that was rarely quantified in tea in other investigations, was detected in young leaves with a content of 0.06 ± 0.02 mg/g d.w. This concentration in Shan Tuyet leaves was significantly higher than that in other types of our samples.…”

“…This concentration in Shan Tuyet leaves was significantly higher than that in other types of our samples. 19 Asp was not detected in Shan Tuyet young leaves while existing in mature leaves of the same variety and in the sinensis variety. Therefore, all the above-mentioned reasons let us hypothesize that Ser, Glu, Arg, Orn, and Asp could be biomarkers in the determination of tea quality and contribute to the traceability of Shan Tuyet tea originating from Son La province of Vietnam.…”

“…This content was the highest for Ser in all the tea varieties and products reported in other research. 12,18,19 Similarly, Glu presented in Shan Tuyet young leaves with a concentration of 1247.3 ± 54.4 µM, corresponding to 1.84 ± 0.08 mg/g d.w., which is higher than that in other sinensis teas in previous studies. 18-20 In contrast, even though Arg was found in the highest concentration in Shan Tuyet young leaves in this study with 86.1 ± 9.6 µM, corresponding to 0.15 ± 0.02 mg/g d.w., this amino acid represented a lower content than in other C sinensis leaves reported in other studies.…”

“…12,18,19 Similarly, Glu presented in Shan Tuyet young leaves with a concentration of 1247.3 ± 54.4 µM, corresponding to 1.84 ± 0.08 mg/g d.w., which is higher than that in other sinensis teas in previous studies. [18][19][20] In contrast, even though Arg was found in the highest concentration in Shan Tuyet young leaves in this study with 86.1 ± 9.6 µM, corresponding to 0.15 ± 0.02 mg/g d.w., this amino acid represented a lower content than in other C sinensis leaves reported in other studies. 12,19 Orn, an amino acid that was rarely quantified in tea in other investigations, was detected in young leaves with a content of 0.06 ± 0.02 mg/g d.w.…”

Metabolic Profiling as an Approach to Differentiate T-Cell Acute Lymphoblastic Leukemia Cell Lines Belonging to the Same Genetic Subgroup

“…Untargeted polar metabolomics chromatographic separation was conducted by following the indications reported by Jian Li et al [53]. For the immobile phase, a Waters XBridge BEH Amide (HILIC) column (150 mm, 2.1 mm, and 2.5 µm) at 25 • C with a flow rate of 0.35 mL/min was used.…”