title: [Determination of four amino acids in tea by capillary zone electrophoresis and direct ultraviolet detection without derivatization].
abstract: Abstract: Four important amino acids, arginine (Arg), tryptophane (Trp), phenylalanine (Phe) and tyrosine (Tyr) in tea samples with different fermentation processes were simultaneously determined by capillary zone electrophoresis (CZE) using direct ultraviolet detection (UV) at 190 nm. Under the conditions of 20 kV of separation voltage and 25 degrees C of temperature, Arg, Trp, Phe and Tyr were separated successfully within 8 min in 25 mmol/L sodium borate-boric acid (pH 10.0) with the detection limits of 5.0, 1.0, 0.3 and 0.5 mg/L for Arg, Trp, Phe and Tyr, respectively. The relative standard deviations (RSDs) of migration time (n = 7) were all lower than 2.8% and the RSDs of peak electric current (n = 7) were lower than 4.0%. The method was applied in the determination of Arg, Trp, Phe and Tyr in eleven tea samples. The results were satisfactory. This method can provide beneficial reference to evaluation quality of tea.
authors.affiliation: Ministry of Education Key Laboratory of Analysis and Detection Technology for Food Safety, College of Chemistry and Chemical Engineering, Fuzhou University, Fuzhou 350002, China.
authors.forename: Qingping
authors.initials: Q
authors.lastname: Wang
authors.forename: Lan
authors.initials: L
authors.lastname: Zhang
authors.forename: Guonan
authors.initials: G
authors.lastname: Chen
authors.forename: Jin-Ming
authors.initials: JM
authors.lastname: Lin
mesh_terms: D000596:Amino Acids / Q000032:analysis*; D019075:Electrophoresis, Capillary / Q000379:methods*; D013662:Tea / Q000737:chemistry*
chemical_list: D000596:Amino Acids; D013662:Tea