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All Journal EKSAKTA: Journal of Sciences and Data Analysis JURNAL KIMIA SAINS DAN APLIKASI Bulletin of Chemical Reaction Engineering & Catalysis Indonesian Journal of Chemistry Bulletin of Chemical Reaction Engineering & Catalysis

Agus Kuncaka

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

Author-ID : 3957378

Chemical Engineering, Chemistry & Bioengineering Chemistry Earth & Planetary Sciences Engineering Materials Science & Nanotechnology

Published : 11 Documents Claim Missing Document

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Studi Pelarutan Perak dengan Hidrogen Peroksida dan Asam Sulfat dalam Sistem Asetonitril/Air Haris, Abdul; Kuncaka, Agus
Jurnal Kimia Sains dan Aplikasi Vol 3, No 3 (2000): Volume 3 Issue 3 Year 2000
Publisher : Chemistry Department, Faculty of Sciences and Mathematics, Diponegoro University

Telah dipelajari pelarutan serbuk perak menggunakan H2O2 dan H2SO4 dalam media air dan media campuran asetonitril-air. Pelarutan serbuk perak dilakukan dengan pengadukan pada kecepatan 400 rpm selama 1,5 jam dan banyaknya Ag yang larut dianalisis dengan SSA. Dari penelitian yang telah dilakukan diperoleh konsentrasi ion Ag+ maksimum yang larut dalam media air sebesar 1,49 x 10-2 M dan dalam media campuran 60%(v/v) asetonitril-air sebesar 2,20 x 10-2 M. Dengan perhitungan pelarutan perak, didapatkan energi bebas transfer standar (DGt0) ion Ag+ dari media air ke media campuran 60% (v/v) asetonitril-air ialah-971,94 joule mol-1. Hasil penelitian menunjukkan bahwa dengan meningkatnya persentase asetonitril dalam media campuran asetonitril-air, maka besarnya DGt0 cenderung makin negatif atau kelarutan ionAg+ makin besar.

Saccharin Extraction And Analysis Of Drug And Food Samples By Derivative Ultraviolet (UV) Spectrophotometry Sarwendah Ratnawati Hermanto; Roto Roto; Agus Kuncaka
EKSAKTA: Journal of Sciences and Data Analysis VOLUME 18, ISSUE 2, August 2018
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20885/eksakta.vol18.iss2.art1

Saccharin extraction and analysis of drug and food samples was investegated by spectrophotometry ultraviolet (uv) derivative method were studied. The saccharin extraction was carried out using solvent of ethanol/chloroform (2:8 v/v). The limit of detection (LOD) and limit of quantification (LOQ) of the proposed method were 0.50 ppm and 1.82 ppm for the second order and 0.47 ppm and 1.58 ppm for the fourth, while for the zero order were 2,75 ppm and 8,55 ppm. The calibration curve was linear in the concentration range from 20-100 ppm (R2= 0.996 for the second order and R2=0.997 for the fourth). The percent recovery of saccharin was in the range 95.20-104.40% for the second order and 97.20-102.40% for the fourth. The range of saccharin concentration (w/w) in drugs, candies and toothpaste for the fourth derivative were 1.39±0.02 mg/kg until 7.15±0.05 mg/kg, 0.21±0.01 mg/kg until 2.09±0.01 mg/kg, and 0.15±0.03 mg/kg until 0.63±0.04 mg/kg, respectively.

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 : Department of Chemical Engineering - Diponegoro University

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

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).

Functionalization of Fe3O4/SiO2 with N-(2-Aminoethyl)-3-aminopropyl for Sorption of [AuCl4]- Nuryono Nuryono; Mighfar Syukur; Agus Kuncaka; Satya Candra Wibawa Sakti
Indonesian Journal of Chemistry Vol 16, No 2 (2016)
Publisher : Universitas Gadjah Mada

Synthesis of Fe3O4/SiO2 modified with N-(2-aminoethyl)-3-aminopropyl group (Fe3O4/SiO2/ED) via coating method and its application for adsorption-desorption of anionic gold in aqueous solution have been conducted. The synthesized product was characterized with an X-ray diffractometer (XRD), a Fourier transform infrared (FT-IR) spectrophotometer and a transmission electron microscopy (TEM). Adsorption of Au(III) was conducted in a batch system and the variables included pH, contact time, and initial concentration were investigated. Results showed that magnetite/silica has been successfully functionalized with N-(2-aminoethyl)-3-aminopropyl in a homogeneous system. Kinetics study showed that adsorption of Au(III) followed the pseudo-second order model with rate constant of 0.710 g mmol L-1min-1. Furthermore, the experimental data fitted well with the Langmuir isotherm model with the maximum adsorption capacity for Au(III) of 142.9 mg g-1 and the energy of 25.0 kJ mol-1. Gold loaded on the Fe3O4/SiO2/ED could be easily desorbed with 0.2 mol L-1 HCl containing 2 wt.% of thiourea with recovery of 99.8%. Fe3O4/SiO2/ED was reusable and stable in 5 cycles of adsorption-desorption with recovery more than 90%. Fe3O4/SiO2/ED showed high selectivity towards Au(III) in the multimetal system Au(III)/Cu(II)/Cr(VI) with the coefficient selectivity for αAu-Cu of 227.5and for αAu-Cr of 12.3.

L-Arginine-Modified Silica for Adsorption of Gold(III) Sri Hastuti; Nuryono Nuryono; Agus Kuncaka
Indonesian Journal of Chemistry Vol 15, No 2 (2015)
Publisher : Universitas Gadjah Mada

In this research, L-arginine-modified silica (SiO2-Arg) with 3-glycidoxypropyl-trimethoxysilane (GPTMS) as the linking agent has been synthesized through sol gel process for adsorption of Au(III) in aqueous solution. Tetraethyl orthosilicate (TEOS) as the silica source precursor, L-arginine solution 0.9 M with various volume ratios and the linking agent were mixed together to form a gel. SiO2-Arg was characterized using Fourier transform infrared (FTIR) spectrophotometer, thermogravimetric analysis (TGA), and an elemental analysis. Adsorption was carried out in a batch system under various experimental conditions including contact time and initial concentration of metal Au(III). The selectivity of adsorbent toward Au(III) was examined in the presence of Cu(II), Fe(III), and Zn(II) ion at various pHs. Results of characterization showed that silica has been successfully modified with L-arginine. The optimum adsorption of Au(III) on SiO2-Arg was obtained at pH of 3.0 and the adsorption isotherm of Au(III) on SiO2-Arg gives the adsorption capacity of 52.79 mg/g. The kinetic study demonstrates that the adsorption of Au(III) ion follows pseudo-second order with the rate constant of 53197 g mol–1 min–1. The selectivity order of Au-Zn = Au-Cu > Au-Fe. This sol-gel preparation is simple and provides prospective application of SiO2-Arg material as an effective adsorbent for metal ions particularly gold(III).

UTILIZATION OF RICE HUSK AS RAW MATERIAL IN SYNTHESIS OF MESOPOROUS SILICATES MCM-41 Suyanta Suyanta; Agus Kuncaka
Indonesian Journal of Chemistry Vol 11, No 3 (2011)
Publisher : Universitas Gadjah Mada

The research about synthesis and characterization of MCM-41 from rice husk has been done. Silica (SiO2) was extracted from rice husk by refluxing with 3M hydrochloric solution at 80 °C for 3 h. The acid-leached rice husk was filtered, washed, dried and calcined at 650 °C for 6 h lead the rough powder of rice husk silica with light brown in color. Characterization was carried out by X-ray diffraction (XRD) and FTIR spectroscopy method. Rice husk silica was dissolved into the sodium hydroxide solution leading to the solution of sodium silicate, and used as silica source for the synthesis of MCM-41. MCM-41 was synthesized by hydrothermal process to the mixture prepared from 29 g of distilled water, 8.67 g of cetyltrimethyl ammonium bromide (CTMAB), 9.31 g of sodium silicate solution, and amount mL of 1 M H2SO4. Hydrothermal process was carried out at 100 °C in a teflon-lined stainless steel autoclave heated in the oven for 36 h. The solid phase was filtered, then washed with deionised water, and dried in the oven at 100 °C for 2 h. The surfactant CTMAB was removed by calcination at 550 °C for 10 h with heating rate 2 °C/min. The as-synthesized and calcined crystals were characterized by using FTIR spectroscopy, X-ray diffraction and N2 physisorption methods. In order to investigate the effect of silica source, the same procedure was carried out by using pure sodium silicate as silica source. It was concluded that silica extracted from rice husk can be used as raw materials in the synthesis of MCM-41, there is no significant difference in crystallinity and pore properties when was compared to material produced from commercial sodium silicate.

ELECTRO-DEGRADATION OF REACTIVE BLUE DYES USING CYLINDER MODIFIED ELECTRODE: Ti/β-PbO2 AS DIMENSIONALLY STABLE ANODE Aris Mukimin; Karna Wijaya; Agus Kuncaka
Indonesian Journal of Chemistry Vol 10, No 3 (2010)
Publisher : Universitas Gadjah Mada

A cylinder modified electrode of the β-PbO2 was fabricated by anodic electro-deposition method on titanium substrate. The PbO2 layer prepared from high acid solution (pH: 0.3) that contains a mixed of 0.5 M Pb(NO3)2, 1 M HNO3, and 0,02 M NaF. The physicochemical properties of the PbO2 electrode were analyzed by using Energy Dispersive X-Ray Analysis and X-Ray Diffraction. The analyses have shown that oxide layer has an O/Pb ratio about 1.6 and the PbO impurities are formed in the surface layer besides the β-PbO2. The modified electrode was used as anode paired stainless cathode in the electro-degradation of reactive blue dye. The results of the electro-catalytic oxidation process of the dye solution were expressed in terms of the remaining intensity dye and chemical oxygen demand (COD) values. The modified electrode has removal efficiency of the reactive blue dye at voltage of 7 V, pH of 7, concentration NaCl of 2 g/L, initial dye concentration of 100 mg/L with simple and short time operations.

ENHANCEMENT OF THE SENSITIVITY AND SELECTIVITY OF THE VOLTAMMETRIC SENSOR FOR URIC ACID USING MOLECULARLY IMPRINTED POLYMER Miratul Khasanah; Mudasir Mudasir; Agus Kuncaka; Eko Sugiharto; Ganden Supriyanto; Siti Wafiroh
Indonesian Journal of Chemistry Vol 10, No 3 (2010)
Publisher : Universitas Gadjah Mada

The sensitivity and selectivity of voltammetric sensor for uric acid can be improved by modifying the working electrode using a polymer with a molecular template (molecularly imprinted polymer, MIP). Polymer and MIP was synthesized from methacrylic acid (MAA) as monomer, ethylene glycol dimethacrylic acid (EGDMA) as cross-linker, uric acid (UA) as template and the results were characterized by various methods. The poly-MAA formation was identified by a decrease in the intensity of infrared (IR) spectra at ~1540 cm-1 (C=C) and an increase at ~1700 cm-1 (C=O) compared to the IR spectra of the MAA and EGDMA. The SEM analysis showed that the cavity of polymer is small enough (~ 0.1 µm) and homogeneous. Establishment of MIP was carried out by extracting of the uric acid from the polymer network. The IR spectra of MIP exhibited the decrease in intensity at ~1700 cm-1 (C=O) compared to the non imprinted polymer (NIP). The data of BET analysis showed that polymer pore size increase slightly from 37.71 Å to 38.02 Å after the extraction process of uric acid from the polymer network. Its may be due to incomplete extraction of uric acid from the polymer network. Modifications of hanging mercury drop electrode using MIP made from MAA, EGDMA, and UA with a mole ratio of 1:3:1 produced a sensitive and selective voltammetric sensor for uric acid. The sensitivity obtained was 16.405 nA L/µg. The presence of ascorbic acid in equal concentration with uric acid decreased the current response of only 0.08%. Compared to HMDE electrode, the sensitivity and selectivity of the HMDE-MIP sensor enhanced about 100 and 700 times, respectively. The detection limit was found to be 5.94 x10-10 M.

Study of the Gold Extraction Using Tetra N-Butyl Ammonium Chloride-Chloroform Yuli Puspito Rini; Agus Kuncaka; Ngatidjo Hadipranoto
Indonesian Journal of Chemistry Vol 1, No 2 (2001)
Publisher : Universitas Gadjah Mada

The existence of the AuCl4- ion in the solution as the function of pH before performing the extraction of gold in the system of tetra N-butylammonium chloride (TBACI) -chloroform has been studied. The experimental data showed that AuCl4- ion was hydrolyzed at pH 5-10 and, an amorf dark-brown precipitate was appeared at pH 11-14. Amount of gold in the solution at pH 14 before extraction was around 70%. Study of the extraction has been carried out by investigating the influence of pH and TBACI concentration on the extraction efficiency. The experimental result indicated that TBACI was very efficient extractant for the extraction of gold from aqueous halide with the efficiency higher than 99%. The extraction of Gold in the TBACI-chloroform was effective at pH 0-4 with minimum concentration of TBACI 10-3 M, and the calculated Kex (extraction constant) was 5.07x10-4.

Study on the Interference of Iron, Aluminium and Silicon on the Atomic Absorption Spectrometric Determination of Mangan in Laterite Mineral Sulistyo Saputro; Ngatidjo Hadipranoto; Agus Kuncaka
Indonesian Journal of Chemistry Vol 1, No 2 (2001)
Publisher : Universitas Gadjah Mada

Interference of iron, aluminum and silicon on the determination of mangan in laterite mineral by atomic absorption spectrometry has been investigated. Dissolution of laterite mineral into solution have been carried out by wet method destruction using combination of 7 mL of aquaregia, 7.5 mL of concentrated perchloric acid and 9 mL of fluoride acid 48% In sealed teflon flask heated at temperature of about 110 °C for 3 hours to determine the content of Mn element in laterite mineral directly. Interference of these three metals were carried out by evaluating the differences of Mn absorbance at wavelength 279.50 nm and slit width 0.2 nm between the solutions containing mangan only and those containing the some amount of mangan together with the interfering elements at those concentration range in laterite mineral. The result showed that both iron at concentration of 100 ppm until 500 ppm and aluminum at concentration at 3 ppm until 15 ppm caused significant and non-linear interference on the determination of Mn 2 ppm. Interference of iron was effectively eliminated by releasing action of aluminum. The signal depression reductional decrease due to 234 ppm of silicon on the determination of Mn 2 ppm can be eliminated by adding 2.30 mL of CaCl2 0.2% (m/v) into these solution. The content of Mn in the laterite mineral after and before adding of CaCl2 into solution were 2407.04 ± 59.26 μg g-1 and 2311.76 ± 23.61 μg g-1, respectively. This result was significantly different at confidence level 95% as shown by the value of tcalculated=4.91 that was higher than ttable=4.30.

Co-Authors Abdul Haris Aris Mukimin Dahlia Rosma Indah, Dahlia Rosma Eko Sugiharto Ganden Supriyanto Karna Wijaya Miratul Khasanah Mudasir Mudasir Ngatidjo Hadipranoto Ni Made Wiratini Nuryono Nuryono Nuryono Nuryono Roto Roto Roto Roto Sarwendah Ratnawati Hermanto Satya Candra Wibawa Sakti Siti Wafiroh Sri Hastuti Sulistyo Saputro Suyanta Suyanta Syukur, Mighfar Triyono Triyono Wega Trisunaryanti Yuli Puspito Rini

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