1. Materials and methods1.1. Chemic

1. Materials and methods

1.1. Chemicals and solutions

HPLC grade methanol and trifluoroacetic acid (TFA, purity P 99%) were obtained from Fisher Scientific International Inc. (Fair Lawn, New Jersey, USA) and Tokyo Chemical Industry Co., Ltd. (Shanghai, China), respectively. Analytical-reagent grade anhydrous ethanol was obtained from Tianjin Fuyu chemical Co., Ltd. (Tianjin, China).
Deionised water used for all the solutions and dilutions was prepared by Ultrapure Water Polishing System of Shanghai Moller scientific instrument Co., Ltd. (Shanghai, China).
Ten chemical standards were purchased from Sigma–Aldrich Co. (St. Louis, Missouri, USA), which are (À)-epigallocatechin gallate (EGCG), (À)-epigallocatechin (EGC), (À)-epicatechin gallate (ECG),(À)-epicatechin (EC), (À)-gallocatechin gallate (GCG), (À)-gallo-catechin (GC), (+) catechin (C), gallic acid (GA), chlorogenic acid (CA), and caffeine (CAF).
The purity of these standards was all above 98%.

Hasil (Bahasa Indonesia) 2:

1. Bahan dan metode 1.1. Kimia dan solusi HPLC kelas metanol dan fl tri asam uoroacetic (TFA, kemurnian P 99%) diperoleh dari Fisher Ilmiah fi c International Inc (Fair Lawn, New Jersey, USA) dan Tokyo Chemical Industry Co, Ltd (Shanghai, Cina), masing-masing . Etanol anhidrat analitis-reagen kelas diperoleh dari Tianjin Fuyu kimia Co, Ltd (Tianjin, Cina). Air yang diawaionkan digunakan untuk semua solusi dan pengenceran disiapkan oleh ultra murni Air Polishing Sistem Shanghai Moller ilmiah instrumen fi c Co, Ltd ( Shanghai, Cina). Sepuluh standar kimia yang dibeli dari Sigma-Aldrich Co (St Louis, Missouri, USA), yang (À) gallate -epigallocatechin (EGCG), (À) -epigallocatechin (EGC), (À) gallate -epicatechin (EKG), (À) -epicatechin (EC), (À) gallate -gallocatechin (GCG), (À) -gallo-catechin (GC), (+) katekin (C), asam galat (GA) , asam klorogenat (CA), dan kafein (CAF). Kemurnian standar ini adalah semua di atas 98%.