Helium: Journal of Science and Applied Chemistry

Electrochemical Oxidation of Methylene Blue Using Carbon Electrode from Battery Waste

Supwatul Hakim — 2024-12-27

Methylene blue in the environment can disrupt the ecosystem because it does not decompose easily. Therefore, this research aims to oxidize methylene blue using an electrochemical oxidation method. The electrochemical oxidation of methylene blue was successfully carried out using carbon electrodes from battery waste. The influence of pH value and electrolysis time was successfully investigated using a UV-Vis spectrophotometer, and the decreased absorbance (DA(%)) was also analyzed. Based on the results, the optimum pH for electrochemical oxidation with a carbon electrode is at pH 1. It was possible to reduce the absorbance at this pH with a decreased absorbance of 56%. There was a decrease in absorption in the UV and visible regions. The optimum time for methylene blue electrochemical oxidation was 15 minutes, with a decreased absorbance percentage at 100%. The electrochemical oxidation method is simple and easy to use. This finding can be an excellent and effective wastewater treatment method.

Fabrication and Characterization of Syringe Carbon Paste Electrode for Electrochemical Measurement

Anom Cahyotomo — 2024-12-27

This study aims to fabricate and characterize a syringe carbon paste electrode (SCPE) using K₃Fe(CN)₆ 10 mM solution with cyclic voltammetry technique. Characterization is performed by varying pH (pH 4, 7, and 10) and scan rate (30 - 100 mV/s) so that the characteristics of SCPE can be observed. The K₃Fe(CN)₆ 10 mM solution test results at various pH variations obtained the largest anodic peak current (Ipa) at pH 10 was 44.75 µA. The scan rate results at various pH showed linear results with the diffusion coefficient of 1.77 x 10^-6 cm²/s, 1.65 x 10^-6 cm²/s, and 2.50 x 10^-6 cm²/s with r values of 0.9994, 0.9975, and 0.9992 for pH 4, pH 7, and pH 10 respectively. This indicated that a diffusion process controlled this system's mass transfer in various pH. The detection of nitrite ions at a concentration of 2 mM showed a clear oxidation peak, with the highest Ipa value of 61.28 µA in pH 7 buffer solution.

A Study on the Addition of Sweet Orange (Citrus sinensis L) to Reduce Goaty Odor in Goat Milk-Based Yogurt

Annisa Desfi — 2024-12-27

This study aimed to reduce the goaty odor in goat milk yogurt by adding sweet orange (Citrus sinensis L). Yogurt was prepared with varying concentrations of sweet orange: 0%, 5%, 10%, and 15% (v/v). The yogurt characteristics analyzed included organoleptic properties, pH, lactic acid, protein, and moisture content. Results showed that adding 15% sweet orange was most effective in reducing goaty odor and increasing consumer preference. The yogurt pH remained stable at 4, while lactic acid content increased to 1.35% compared to the control (1.26%). Protein content decreased with increasing orange concentration, while moisture content increased. This study concludes that adding sweet oranges effectively reduces the goaty odor in goat milk yogurt, although attention should be paid to the decrease in protein content. These findings open opportunities for developing more appealing goat milk yogurt products for Indonesian consumers.

Conductive Electrospun Nanofibers in The Electrochemical Sensor for Determination of Idarubicin

Hamed Khorami — 2025-01-29

The study reports the manufacturing of innovative electrochemical sensors using iron oxide ceramic nanofibers (Fe₃O₄ and Fe₂O₃) and polyether sulfone nanofibers (PES) to detect idarubicin in blood with sensitive and selective detection. The hybrid nanofiber matrix offers high surface area, excellent conductivity, and synergistic electrocatalytic properties, ideal for detecting idauricin in complex biological matrices. The sensor exhibits a wide linear detection range and remarkable sensitivity. The detection limit was suitable, indicating its ability to detect idarubicin at subclinical concentrations. The device showed excellent selectivity and minimal interference from biological analytes, ensuring reliable performance in blood samples. Repeated experiments measured a relative standard deviation (RSD) of 1.7%, while the repeatability of the independently manufactured sensor showed an RSD of 1.7%, demonstrating the robustness of the manufacturing process. Integrating Fe₃O₄/Fe₂O₃ ceramic nanofibers with PES offers a novel approach to overcoming the challenges of electrode and biofouling in blood. The sensor showed high recovery rates in human blood samples, confirming its application in clinical diagnostics. This paper presents a cost-effective and scalable method for constructing hybrid nanofiber electrochemical sensors with high sensitivity, selectivity, and repeatability. The result highlights the potential of Fe₃O₄/Fe₂O₃-PES nanofibers as a platform for developing next-generation point-of-care devices for monitoring chemotherapy drugs.