Determination of catechins and methylxanthines in foodstuffs by semi-micro high performance liquid chromatography

• Published in: Food Hygiene and Safety Science (Shokuhin Eiseigaku Zasshi) Vol. 33; no. 4; pp. 347 - 354_1
• Main Authors: Terada, H. (Nagoya-shi. Health Research Inst. (Japan)), Suzuki, A, Tanaka, H, Yamamoto, K
• Format: Journal Article
• Language: English; Japanese
• Published: Japanese Society for Food Hygiene and Safety 1992
• Subjects: ANALISIS CUANTITATIVO; ANALYSE QUANTITATIVE; CAFEINA; CAFEINE; CAFFEINE; catechin; CHROMATOGRAPHIE; CHROMATOGRAPHY; COMPOSE ORGANIQUE; COMPUESTOS ORGANICOS; CROMATOGRAFIA; epicatechin; epicatechin gallate; epigallocatechin; epigallocatechin gallate; ORGANIC COMPOUNDS; QUANTITATIVE ANALYSIS; semi-micro high performance liquid chromatography; TE; TEA; THE; theobromine; theophylline
• ISSN: 0015-6426; 1882-1006
• DOI: 10.3358/shokueishi.33.347

A simple and widely applicable method for the simultaneous determination of 5 kinds of catechins, i. e., epigallocatechin (EGC), epigallocatechin gallate (EGCg), epicatechin (EC), epicatechin gallate (ECg) and catechin (C), and 3 kinds of methylxanthines, i. e., theobromine (TB), theophylline (TP) and caffeine (CA), by semi-micro high performance liquid chromatography was developed. The sample was extracted with 40% aqueous ethanol and cleaned up by use of a Sep pak C18 cartridge. The extract was chromatographed on asemi-micro size Inertsil ODS-2 column (2.1mm i. d.×250mm) with a mobile phase of methanol-water-0.2M phosphate buffer pH 3.0 (12:33:5). The detection was achieved with a UV monitor set at 207nm. The recoveries from sencha (common grade green tea), maccha icecream (icecream containing finely ground green tea), maccha senbei (Japanese cracker containing finely ground green tea), maccha jelly (jelly containing finely ground green tea) and candy containing oolong tea extract were 90.9-120.4% (CV 0.8-6.4%) for EGC, 91.8-117.3% (CV 0.4-6.3%) for EGCg, 91.2-96.7% (CV 0.9-3.1%) for EC, 83.2-104.3% (CV 1.5-9.4%) for ECg, 90.2-101.6% (CV 3.1-5.6%) for C, 53.0-106.4% (CV 1.0-11.0%) for TB, 74.6-101.6% (CV 0.8-3.3%) for TP and 88.4-98.8% (CV 0.9-4.1%) for CA. The detection limits were 0.1μg/g for each compound.