MOLECULARLY IMPRINTED POLYMER FOR SOLID PHASE EXTRACTION OF CATECHIN AND ITS DERIVATIVES

• Main Author: TRIADHI, UNTUNG
• Format: Dissertations
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/31417
• Institution: Institut Teknologi Bandung

<p align="justify">Tea leaves (Camellia sinensis) consist of polyphenol compounds that serve as antioxidant. Catechin (C), epicatechin (EC), epicatechin gallate (ECG), epigallocatechin (EGC) and epigallocatechin gallate (EGCG) are several types of polyphenol that contain in tea leaves. EGCG has the highest antioxidant activity and its activity is a hundred times greater that vitamin C (ascorbic acid). Aside of polyphenol, Tea leaves also contain caffeine, that if consumed excessively, will give effect such as insomnia, anger disorder problem, and even nerve system damage. For all that reasons, development of new separation technique for polyphenol compounds especially catechin group from tea leaves are needed. <br /> <br /> Molecularly imprinted polymer that has been introduced since 1980s, has developed rapidly over the last few decades. The MIP ability to create molecule template that match size and afinity of particular molecule, make this technique very important to develop. Easy and inexpensive preparation, the stability of heat, acid, temperature, and high pressure and extreme conditions are the advantages of this method. MIP can be synthesized using monomer and crosslinker and also the presence of template molecules. The selection of initiator will give effect to polymerization and the usage of porogen will relate to pore formation on MIP. <br /> <br /> Catechin and EGCG that are used as template molecule for MIP method are not well published. In this research, MIP has sucessfully been systhesized with methacrylic acid (MAA) as monomer, ethyleneglycol dimethacrylate (EDGMA) as crosslinker, benzoyl peroxide (BPO) as polymerization initiator and acetonitrile (ACN) as porogen. There are several template molecules that were used such as catechin and epigallocatechin gallate. Mol (mmole) ratio of MAA:EDGMA:BPO is 5:30:0.5. Non imprinted polymer (NIP) serves as control that is made same as MIP but without template molecule. NIP, CIP and EGCIP was characterized using infrared spectroscopy and SEM image. <br /> <br /> Thermal stability of NIP, CIP and EGCGIP have been studied by TGA analysis. The highest mass reduction for NIP, CIP and EGCGIP were happened at temperature 290 oC, 440 oC, and 380 oC, respectively. Analysis of surface area indicates that EGCGIP has the biggest surface area that is 76.31 m2/g, followed by CIP 17.93 m2/g and the least is NIP 9.79 m2/g. EGCGIP has the biggest pore radius compared to CIP and NIP that is 4.21 nm. This data is confirmed by SEM Images. <br /> <br /> The solid phase extraction was applied by methanol-water (90/10, %v/v) and methanol as solvents. The maximum absorption wavelength for catechin and epigallocatechin gallate are 280 nm and 275 nm, respectively. HPLC was applied by using C18 Coloumn (5 µm, 150 x 4.6 mm) with methanol-water (30/70, %v/v) as mobile phase with flow rate 10 mL/min. A traditional C18 SPE cartridge was used as comparison. Retention time for catechin and EGCG are 3.917 min and 5.576 min, respectively. Adsorption percentage of catechin with 100 ppm catechin standard solution for NIP, CIP and C18 are 53.46%, 83.69% and 93.90%, respectively. Adsorption percentage of 100 ppm EGCG standard solution for NIP, CIP and C18 are 86.76%, 95.01% and 84.07% respectively. Adsorption percentage of EGCG for EGCGIP cannot be measured because chromatogram peak of EGCG too small to be read. Samples that are used was commercial tea leaves. This samples have been processed so there are composition changes. EGCG level on tea samples is 6.87 ppm and catechin is 3.72 ppm. <p align="justify"> <br /> <br />