VOLTAMMETRIC DETERMINATION OF NICKEL(II) USING CARBON PASTE ELECTRODE MODIFIED WITH DMG, MAGNETITE, AND SILVER NANOPARTICLES

• Main Author: Nega Reni Damayanti, Ajeng
• Format: Theses
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/79210
• Institution: Institut Teknologi Bandung

Nickel is one of the metals frequently used in industries such as metal coating, construction, and machinery. Consequently, waste containing nickel often enters the aquatic environment. Nickel concentrations exceeding the threshold can endanger the health of aquatic organisms and humans. Therefore, a sensitive, fast, and simple analytical method is needed to monitor nickel levels in water. In this research, a voltammetric method for measuring nickel in water samples was developed using a carbon paste electrode (CPE) modified with dimethylglyoxime (DMG), magnetite (Mag), and silver nanoparticles (AgNPs). The working electrode, both unmodified and modified, was characterized using SEM-EDS. The evaluation of the peak current reduction of Ni(II) using CPE-DMG-Mag-AgNPs showed higher results compared to other electrodes. A series of optimization processes were carried out to achieve optimum measurement results, including measurement technique optimization, DMG and magnetite composition optimization, and potential and deposition time optimization. Under optimum conditions, the performance of CPE-DMG-Mag-AgNPs showed good repeatability and reproducibility, as evidenced by smaller measurement RSD values compared to Horwitz RSD values. Scanning rate analysis data indicated that the electron transfer process was predominantly controlled by the adsorption process. The linear measurement range was between 2-10 nM with a LOD value of 6x10-1 nM. CPE-DMG-Mag-AgNPs demonstrated selectivity for Ni(II) ions in the presence of interfering ions such as Zn(II), Mn(II), and Cu(II). To validate the voltammetric method with the working electrode CPE-DMG-Mag-AgNPs, a comparison of the test results was conducted using AAS. The statistically analyzed data showed no significant difference between the two methods at a 95% confidence level. Testing river water samples using CPE-DMG-Mag-AgNPs revealed a Ni(II) concentration of 12.036 nM, which is below the established threshold.