CARBON PASTE ELECTRODE MODIFIED WITH POLY(GLUTAMIC ACID) FOR VOLTAMMETRIC DETERMINATION OF MELAMINE

• Main Author: NOVITA SARI (NIM : 20513017), SISKA
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/24313
• Institution: Institut Teknologi Bandung

Melamine is an organic compound used as raw material to manufacture melamine-formaldehyde resin. Melamin has been illegally added to dairy product to show a false increase in protein concentration, because it has high nitrogen content (66% of mass). If melamine is consumed in high concentration it will give negative impact to human health. Therefore, determination of melamine is required for human health. Electrochemical methods are widely used in food analysis because they are simple, fast, and low cost. Voltammetry is one of electrochemical method that is widely used. In this study, we develop a new method for voltammetric determination of melamine using carbon paste electrode. The measurement was conducted in two steps. First, melamine was trapped during electropolymerization of glutamic acid on the surface of carbon paste electrode and then the trapped melamine was oxidized to obtained melamine oxidation peak. The polymerization was made using cyclic voltammetry tecnique (6 cycle) in potential range of 0.0 V – 1.8 V and scan rate of 100 mV/s in solution containing melamine and 5 mM glutamic acid. Oxidation of melamine was carried out in an acidic supporting electrolyte solutions. Repeated measurement gave a relative standard deviation of 12.51% (n = 20). The calibration curve was linier in the concentration range of 0.05 mM – 1.00 mM (R2 = 0,998) with detection limit of 20.1 μM. Determination of spiked infant formula and milk samples resulted in percent recovery of between 97.96% -104.02% showing good accuracy of the method. This method can also be used for determination of melamine in real sample.