Agus Kuncaka
Department Of Chemistry, Faculty Of Mathematics And Natural Sciences, Universitas Gadjah Mada, Sekip Utara PO BOX BLS 21 Yogyakarta 55281

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Graphite/NiO/Ni Electrode for Electro-oxidation of the Remazol Black 5 Dye Ni Made Wiratini; Triyono Triyono; Wega Trisunaryanti; Agus Kuncaka
Bulletin of Chemical Reaction Engineering & Catalysis 2021: BCREC Volume 16 Issue 4 Year 2021 (December 2021)
Publisher : Masyarakat Katalis Indonesia - Indonesian Catalyst Society (MKICS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.9767/bcrec.16.4.11702.847-856

Abstract

Graphite/NiO/Ni electrode had been fabricated for the electro-oxidation of remazol black 5 dye. The electrode was synthesized by electrodeposition method. Electro-oxidation of 100 ppm remazol black 5 dye was carried out at various concentrations of NaCl, 0.025; 0.05; 0.1; 0.25; and 0.5 M, variations in electro-oxidation time were 15, 30, 45, and 60 minutes, and pH variations were 4, 6, and 8. Cyclic voltammetry test revealed that graphite/NiO/Ni electrode had higher electrocatalytic capability compared to graphite electrode. The X-ray diffraction (XRD) patterns showed the decreasing value of 2θ from 44.6° for Ni to 43.5° for NiO. Scanning Electron Microscopy-Energy Dispersive X-ray (SEM-EDX) showed that NiO/Ni deposited on the graphite surface in the form of solid grains and cracks, FTIR showed that δ(Ni−O) bond appeared at 582–511 cm−1. The decolorization efficiency of remazol black 5 for graphite/NiO/Ni electrode was 100% for 45 minutes of the electro-oxidation process, while the decolorization efficiency of remazol black 5 for graphite electrode was 99.74% for 60 minutes of the electro-oxidation process. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0). 
Synthesis of Mesoporous Silica from Palm Oil Boiler Ash (MS-POBA) with Addition of Methyl Ester Sulfonate as a Template for Free Fatty Acid Adsorption from Crude Palm Oil (CPO) Sitohang, Cita; Kuncaka, Agus; Suratman, Adhitasari
Indonesian Journal of Chemistry Vol 24, No 3 (2024)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.87703

Abstract

The synthesis of mesoporous material by utilizing palm oil boiler ash (POBA) waste as the silica source and methyl ester sulfonate (MES) surfactant as the template for a high-porosity was investigated for free fatty acids (FFA) adsorption. The research was initiated with silica extraction from POBA by sodium hydroxide addition through the sol-gel precipitation method. Silica modification was carried out with MES surfactant and 3-aminopropyltrimethoxysilane (APTMS) as the co-structure-directing agent (CSDA) in different calcination temperatures. Mesoporous silica-POBA (MS-POBA) free template had a surface area, pore diameter, and pore volume (41.033 m2/g, 4.180 nm, and 0.250 cm3/g) lower than MS-POBA with the template (71.0147 m2/g, 7.923 nm, and 0.524 cm3/g). The ability of MS-POBA to adsorb FFA reached its optimum conditions with an adsorption time of 20 min and an adsorbent dosage of 0.24 g. The FFA removal by MS-POBA with the template was found to have higher adsorption ability, which was 35.54%, compared to the MS-POBA free template of 26.68%. The high porosity of MS-POBA with a template makes the FFA adsorption capacity of this material higher than MS-POBA free template.
Validation of Boron Analysis Method on SRM Tomato Leaves NIST No. 1573a using Fluorescence Spectrophotometry Lailatusholihah, Isna; Tri Utami, Aisyiah Restu; Roto, Roto; Kuncaka, Agus
Jurnal Kimia Fullerene Vol 10 No 1 (2025): Fullerene Journal Of Chemistry
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.37033/fjc.v10i1.661

Abstract

The study of borax contamination on SRM Tomato Leaves NIST no. 1573a was succesfully analized. This study used sausage samples using Spectrophotometry Fluoresence method. Boron analysis by fluorescence spectrophotometry was done by excitation at 522 nm and emission at 593 nm. Validation method uses linear standard curve in the concentration range of 1-4.5 ppm with R2 = 0.9991. The sensitivity, limit of detection, limit of quantification, and percent recovery are 4695.7 a.u.ppm-1, 0.241±0,06 ppm, 0.805±0,06 ppm, and 92.8%, respectively. This means that determining boron using the borate ester distillation method with fluorescence spectrophotometry can be used as a new method for determining boron levels in food samples.