SYNTHESIS AND CHARACTERIZATION OF MOLECULAR IMPRINTED POLYMER FOR ANALYSIS OF DIMETHYLAMILAMINE AS DOPING COMPOUNDS IN FOOD SUPPLEMENTS USING HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY

• Main Author: Amin, Saeful
• Format: Dissertations
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/35096
• Institution: Institut Teknologi Bandung

Doping is defined by WADA as the use of prohibited substances by athlete's, refusing to collect samples for inspection purposes, violating inspection requirements, carrying out damage during supervision, having prohibited substances or methods, and providing prohibited substances or methods. One of stimulant compounds which is prohibited and considered as doping is dimethylamilamine (DMAA). DMAA is generally added to athletes' dietary supplements. The research began with the selection phase of the monomers which will be used through computational studies and ended with the stages of separation of DMAA in food supplement samples. The steps were carried out during the study include preliminary research consisting of the determination of functional monomers through in silico studies of the interaction of template-monomer molecules and determination of Gibbs free energy and bonding energy. MIP synthesis was carried out by the bulk method. DMAA acted as a template molecule, acrylamide methacrylic acid, and itaconic acid as a functional monomer, ethylene glycol dimethacrylate as a crosslinker, and 2.2'-azoisobutironitrile as an initiator dissolved in chloroform. Comparison of template molecules, functional monomers, and crosslinkers was 1:4:20 (mol). The polymerization was initiated by heating at 60o C. The release of template molecules was done by extraction using the ultrasonication technique. The extraction was repeated using chloroform as a solvent until the template molecules were released completely. The printed polymer of solid phase extraction molecule (MISPE) was made by inserting MIP into the solid phase extraction catridge. The selectivity of MISPE was determined by comparing the results of recovery between DMAA, ephedrine, and phenylpropanolamine. MISPE performance tests were carried out by using DMAA which was added to food supplements. Supernatant results from solid phase extraction were measured using HPLC, then the recovery was calculated. Verification of the analysis method was carried out with the parameters tested including linearity, accuracy, and precision. v Computational studies results used Gaussian software with quantum mechanical DFT B3LYP method on basis set of 6-311G, selection of functional monomers for synthesis of MIP DMAA template molecules with Gibbs free energy parameters (?G) and bond energy (?E). From 33 monomers, 7 resulted monomers names 2- acrylamide-1-ethane sulfonic acid, itaconic acid, methacrylate acid, acrylic acid, N-(2-hydroxyethyl) acrylamide, methyl 6-O-methacryloil-?-d-glucoside, and acrylamide. The optimum condition of HPLC system was obtained by using C18 octadecylsilane column; 250 × 4.6 mm; 5 µm, mobile phase of acetonitrile: water (9:1), the flow rate of 0.6 mL/minute, and was detected at a wavelength of 313 nm, detection limit and quantification limit of 44.18 ppm and 147.26 ppm respectively. Monomers of methacrylate acid, acrylamide, and itaconic acid could be used as monomers in the synthesis of MIP with DMAA template molecules using the bulk method through heating at 60o C for 7 hours. Sorbent were made selectively extracted DMAA and could be synthesized by polymerization with bulk method with a ratio of template molecule: monomers: crosslinking of 1:4:20 (in moles). Characterization of MIP and NIP using Scanning Electron Microscopy (SEM) showed morphological differences. Characterization of MIP and NIP using Fourier Transform Infrared (FTIR) showed that the functional groups and fingerprints detected a peak that appears at the same wave number between MIP and DMAA which was not found in NIP. The optimum condition in selective extraction of DMAA was using chloroform solvents. The adsorption capacity was determined by the batch method by using sonication for the introduction of DMAA to the MIP cavity and was incubated for 24 hours to allow the interaction of DMAA towards MIP. After incubation, the solution was filtered and each filtrate was analyzed using HPLC and its concentration was calculated. The results of DMAA testing in the MIP, it was obtained that IF for methacrylate acid, acrylamide, and itaconic acid were 2.03; 2.11; and 3.02. In sorbent adsorption mechanism with methacrylic acid and acrylamide, MIP followed the Langmuir isotherm model while NIP followed the Freundlich isotherm model. In sorbent adsorption mechanism with itaconic acid monomer, MIP and NIP followed the Langmuir isotherm model. Determination of desorption capacity was carried out by adding chloroform, ethyl acetate, methanol. The concentration of the mixture was filtered and analyzed using HPLC. The highest desorption concentration was obtained in chloroform. In MIP with methacrylate acid monomers, acrylamide, and itaconic acid, the percentage of DMAA concentrations desorbed was higher than that of methanol. The result of desorption capacity in three solvents in the solid phase extraction process resulted in the best re-binding of the same solvent as when polymerizing. vi The percent value of DMAA recovery obtained by using the MISPE extraction method with methacrylic acid monomers, acrylamide, and itaconic acid, were 37.20, 98.33, and 94.20 %, respectively. The results of the study showed that solid phase extraction sorbent with the technique of molecularly printed polymer for DMAA extraction selectively can be made by using bulk polymerization method. Acrylamide monomers are functional monomers that can be used for the development of solid phase extraction sorbents that are selective for DMAA compounds.