CARBON PASTE ELECTRODE MODIFIED WITH TIO2 AND MOLECULARLY IMPRINTED POLYPYROLE FOR TBHQ ANALYSIS BY VOLTAMMETRY

• Main Author: Firdaus Ramdhani, Zidhan
• Format: Final Project
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/83128
• Institution: Institut Teknologi Bandung

Tert-butylhydroquinone (TBHQ) is an antioxidant compound that is often used in the food and beverage industry to extend shelf life and prevent oxidation. The reasonable limit for the use of TBHQ antioxidants set by the Indonesian National Standard (SNI 01-0222-1995) is no more than 200 mg/kg. This research aims to develop a carbon paste electrode (EPK) modified with TiO2 and molecularly imprinted polypyrrole to detect TBHQ voltammetrically. TiO2 was used to increase electrode sensitivity while Molecularly Imprinted Polymer (MIP) polypyrrole was used as a selective element to recognize and improve electrode performance for TBHQ detection. Based on research, EPK modified with TiO2 via the drop method on the EPK surface with a concentration of 15 mg/mL TiO2 and a TBHQ:Ppy composition of 1:3 with a total of 15 electropolymerization cycles is the optimum composition capable of increasing the sensitivity and selectivity of EPK against TBHQ based on current. the highest oxidation peak produced. The optimum condition for measuring TBHQ is TBHQ in PBS pH 7 using the square wave voltammetry technique. Determination of electrode performance is seen from the repeatability of TBHQ measurements using 1 EPK (relative standard deviation 2.127) and the repeatability of making 3 EPKs (relative standard deviation 3.111). Scan rate analysis shows that the processes occurring on the electrode surface are controlled by diffusion processes. This modified EPK has three working concentration ranges, namely, 0.001-0.01mM (R2=0.995), 0.01-0.1 mM (R2=0.991), and 0.1-1 mM (R2=0.991), with limits detection of 0.455 ?M. Meanwhile, TBHQ measurements in instant noodle seasoning oil samples gave results of 86.21 mg/kg and 91.07 mg/kg respectively for the voltammetry and HPLC methods. Thus, TiO2 modified EPK and molecularly imprinted polypyrrole can be used to analyze TBHQ voltammetrically with good performance.