CARBON PASTE ELECTRODE MODIFIED WITH GRAPHENE AND MOLECULARLY IMPRINTED POLY(METHYL ORANGE) FOR VOLTAMMETRIC DETERMINATION OF BUTYLATED HYDROXYANISOLE

• Main Author: Pratiwi, Yusiana
• Format: Theses
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/57337
• Institution: Institut Teknologi Bandung

Butylated hydroxyanisole (BHA) is an additive compound commonly used in the food and cosmetics industry. This compound functions as an antioxidant that can slow down the damage or change in color and smell of the product due to the oxidation process. However, excessive use of BHA as an additive can have a carcinogenic effect on the body. Therefore, an effective analytical quantification method is needed to monitor the use of BHA as an additive in products. Several methods for BHA analysis have been reported such as spectrophotometry and High Performance Liquid Chromatography (HPLC). However, those method still has disadvantage such as long response times, complicated procedures, and high costs. Voltammetry method is one of the analytical methods currently being developed and has several advantages such as high sensitivity and selectivity, relatively low operational costs, simplicity of sample preparation, short analysis time, low detection limit, and broad linear area. The development of the voltammetric method focuses on improving the performance of the working electrode which has been modified to increase the sensitivity and selectivity of the working electrode in the analyte measurement process. In this research, a method was developed for voltammetric determination of BHA using carbon paste electrode (CPE) modified with reduced graphene oxide and molecularly imprinted poly(methyl orange) (MIP). Reduction of graphene oxide was conducted using Square Wave Stripping Voltammetry (SWSV) technique. The effects of electropolymerization cycles, the composition of the MIP solution, and the solution pH on BHA measurements were also studied. Electropolymerization of methyl orange was studied in a solution containing BHA and MO with the composition of BHA:MO = 1:1 to 1:5 using Cyclic Voltammetry (CV) techniques (5 to 30 cycles) over a potential range of -500 to 1200 mV. Optimum electropolymerization condition was obtained with BHA and MO composition of 1:3 and 10 cycles. The optimization of pH measurement was carried out at the pH range of 3 - 8 with the optimum pH of 5. CPE modified with graphene and MIP(methyl orange) showed good repeatability with a linear range of 3 - 100 ?M and a detection limit of 0.49 ?M. The scan rate analysis showed that the electron transfer process was controlled by diffusion. The modified electrode shows good selectivity towards interfering compounds. Determination of BHA in real sample resulted in recovery percentage in range of 95.7% to 99.4%.