MODIFICATION OF CARBON PASTE ELECTRODE WITH MOLECULARLY IMPRINTED POLY(GLUTAMIC ACID) FOR POTENSIOMETRIC DETERMINATION OF RHODAMIN B

• Main Author: (NIM:10512037), FERIZAL
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/27299
• Institution: Institut Teknologi Bandung

Rhodamin B is a synthetic dye used to dye textile, paper, and ceramic materials. In addition, rhodamin B is also used for coloring ingredients in food ingredients such as crackers, syrups, candy, cakes, and even often used for lipstick coloring. The accumulation of rhodamin B in the body can cause damage to the liver, kidneys and lymph. Regulation of the Minister of Health No. 293 / Men.Kes / Per / V / 85 states the prohibition on the use of rhodamin B as a food additive. Determination of rhodamin B can be done using UV-Vis spectrophotometry, high pressure liquid chromatography, fluorophotometry and solid phase extraction. Some methods of determining rhodamin B have disadvantages including complicated sample preparation, the use of expensive reagents. Analysis with potentiometric method has several advantages including fast analysis time, simple work method, and high sensitivity and selectivity. In this study developed carbon paste electrode (EPK) which was modified with molecularly imprinted polymers (glutamic acid) for the determination of rhodamin B with potentiometric techniques. Modification was carried out by electropolymerization of glutamic acid monomer from a solution containing 3.0 mM glutamic acid and 1.0 mM rhodamin B in pH 7 phosphate bufer using 15 cyclic voltammetry technique in a potential range of -0.2 V - 1.8 V with a scan rate of 100 mV / sec. Measurements with these electrodes have optimum performance at pH 5. Nerst factor is 29.2 mV / decade. Measurement range is 10-5 M - 10-2 M, the detection limit of rhodamin B which can be measured by an electrode of 8.91 x 10-6 M. This electrode has accuracy and precision value, and does not have a significant difference if compared with UV-Vis spectrophotometry method.