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Separation of catechins and methylxanthines in tea samples by capillary electrochromatography
Author(s) -
Dilek Uysal Ulku,
Aturki Zeineb,
Raggi Maria Augusta,
Fanali Salvatore
Publication year - 2009
Publication title -
journal of separation science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.72
H-Index - 102
eISSN - 1615-9314
pISSN - 1615-9306
DOI - 10.1002/jssc.200800634
Subject(s) - chemistry , chromatography , capillary electrochromatography , ammonium acetate , analyte , detection limit , electrochromatography , polyphenol , resolution (logic) , analytical chemistry (journal) , capillary electrophoresis , solid phase extraction , catechin , high performance liquid chromatography , organic chemistry , artificial intelligence , computer science , antioxidant
In this paper, the simultaneous separation of several polyphenols such as (+)‐catechin, (–)‐epicatechin, (–)‐epigallocatechin, theophylline, caffeine in green and black teas by capillary electrochromatography (CEC) was developed. Several experimental parameters such as stationary phase type, mobile phase composition, buffer and pH, inner diameter of the columns, sample injection, were evaluated to obtain the complete separation of the analysed compounds. Baseline resolution of the studied polyphenols was achieved within 30 min by using a capillary column (id 100 μm) packed with bidentate C 18 particles for 24.5 cm and a mobile phase composed of 5 mM ammonium acetate buffer pH 4 with H 2 O/ACN (80:20, v/v). The applied voltage and the temperature were set at 30 kV and 20°C. Precision, detection and quantification limits, linearity, and accuracy were investigated. A good linearity ( R 2 > 0.9992) was achieved over a concentration working range of 2–100 μg/mL for all the analytes. LOD and LOQ were 1 and 2 μg/mL, respectively, for all studied compounds. The CEC method was applied to the analysis of those polyphenols in green and black tea samples after an extraction procedure. Good recovery data from accuracy studies ranged between 90% and 112% for all analytes.