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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ELECTRO-DEGRADATION OF REACTIVE BLUE DYES USING CYLINDER MODIFIED ELECTRODE: TI/β-PBO2 AS DIMENSIONALLY STABLE ANODE Mukimin, Aris; Wijaya, Karna; Kuncaka, Agus
Indonesian Journal of Chemistry Vol 10, No 3 (2010)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (215.508 KB) | DOI: 10.22146/ijc.21431

Abstract

A cylinder modified electrode of the ?-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 ?-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.
SACCHARIN EXTRACTION AND ANALYSIS OF DRUG AND FOOD SAMPLES BY DERIVATIVE ULTRAVIOLET (UV) SPECTROPHOTOMETRY Hermanto, Sarwendah Ratnawati; Roto, Roto; Kuncaka, Agus
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

Abstract

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. 
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

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (2464.108 KB) | DOI: 10.14710/jksa.3.3.203-207

Abstract

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.
STUDY OF THE GOLD EXTRACTION USING TETRA N-BUTYL AMMONIUM CHLORIDE-CHLOROFORM Rini, Yuli Puspito; Kuncaka, Agus; Hadipranoto, Ngatidjo
Indonesian Journal of Chemistry Vol 1, No 2 (2001)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (5022.747 KB) | DOI: 10.22146/ijc.21947

Abstract

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 EFFECT OF PH AND METAL CONCENTRATION ON THE SYNTHESIS OF DIMENSIONALLY STABLE ANODE GAPHITE/LA2O3-ZRO2 AND GAPHITE/RUO2-TIO2 Suyanta, Suyanta; Kuncaka, Agus
Indonesian Journal of Chemistry Vol 6, No 2 (2006)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (213.623 KB) | DOI: 10.22146/ijc.21747

Abstract

The objective of this research is to study the effect of pH and metal concentration toward the mass of metal oxides coated on gaphite in the synthesis of dimensionally stable anode (DSA) gaphite/La2O3-ZrO2 and gaphite/RuO2-TiO2. The synthesis of those  DSA was done by thermal decomposition technique. The solution containing metal ion to be coated (as its oxides) on the gaphite, followed by heating. Those spraying and heating were repeated up to ten times, so that it was expected that all of gaphite surface was covered by the metal oxides. It was concluded that the mass of metal oxides coated on the gaphite was affected by the pH and concentration of metals in the solutian to be sprayed. Treatment by using solution at pH of 4 and 6 produced  more in mass of metal oxides mixture than  using solution of 1 and 2 on pHs. DSA gaphite/La2O3-ZrO2 produced by treatment using solution of 4 and 6 on pHs contained more in mass of La2O3 than of ZrO2; meanwhile DSA gaphite/RuO2-TiO2 produced in this research (for all of treatment) contained more in mass of RuO2 than of TiO2.
HYDROTALSIT Zn-Al-EDTA SEBAGAI ADSORBEN UNTUK POLUTAN ION Pb(II) DI LINGKUNGAN Roto, Roto; Indah, Dahlia Rosma; Kuncaka, Agus
Jurnal Manusia dan Lingkungan (Journal of People and Environment) Vol 22, No 2 (2015)
Publisher : Pusat Studi Lingkungan Hidup Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1.84 KB)

Abstract

Polusi ion Pb(II) di dalam lingkungan perairan cenderung naik seiring peningkatan jumlah industri smelter dan daur ulang aki bekas. Penelitian ini bertujuan untuk menguji kemampuan hidrotalsit Zn-Al-EDTA sebagai adsorben ion Pb(II) dalam air secara mendalam. Hidrotalsit Zn-Al-NO3 disintesis dengan metode kopresipitasi dan hidrotermal pada temperatur 100 °C selama 15 jam. Hidrotalsit Zn-Al-EDTA diperoleh dengan penukaran ion. Keasaman larutan, kinetika dan kapasitas adsorpsi diteliti. Hidrotalsit Zn-Al-EDTA memiliki d003 sebesar 14,52 Å sementara Zn-Al-NO3 sebesar 8,90 Å. Spektra FTIR menunjukkan keberadaan serapan gugus C=O pada bilangan gelombang 1684,77 cm-1. Kondisi optimum adsorpsi ion Pb(II) terjadi pada pH 4, waktu kontak 60 menit dan kapasitas adsorpsi diperoleh 2,07 mg/g pada konsentrasi awal 10 mg/L dengan berat adsorben 0,100 g. Adsorpsi ion Pb(II) oleh hidrotalsit Zn-Al-EDTA mengikuti reaksi pseudo orde dua dengan tetapan laju adsorpsi sebesar 8,90 g mmol-1min-1. Adsorpsi ion Pb(II) oleh Zn-Al-EDTA terjadi karena  pembentukan khelat Pb-EDTA di dalam struktur hidrotalsit. Hasil ini diharapkan mampu memberikan kontribusi yang lebih luas di dalam pengendalian konsentrasi Pb(II) di lingkungan.
IMPREGNASI BASAH FE3+ KE DALAM SILIKAT MESOPORI MCM-41-TERSILILASI. ., Suyanta; Kuncaka, Agus
GANENDRA Majalah IPTEK Nuklir Volume 16 Nomor 1 Januari 2013
Publisher : PSTA BATAN

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (508.746 KB) | DOI: 10.17146/gnd.2013.16.1.477

Abstract

Dalam penelitian ini dilakukan impregnasi basah (wet impregnation) Fe3+ ke dalam MCM-41-tersililasi dengan optimasi konsentrasi Fe3+, waktu dan temperatur. Analisis kristalinitas inang didasarkan pada intensitas puncak bidang [100] difraktogram, analisis kuantitatif Fe dalam MCM-41-tersililasi dilakukan dengan metode AAS, sedang karakterisasi Fe-MCM-41-tersililasi dilakukan dengan metode-metode spektroskopi DRUV-Vis, spektroskopi EPR, dan FTIR. Diperoleh kesimpulan bahwa semakin besar konsentrasi Fe3+ dalam larutan prekursor cenderung meningkatkan kandungan Fe dalam Fe-MCM-41-tersililasi, namun jika digunakan larutan prekursor dengan konsentrasi Fe3+ ? 0,1 M berakibat terjadinya kerusakan struktur heksagonal MCM-41-tersililasi. Waktu kontak optimal adalah 8 jam, sedang temperatur optimalnya 40 ºC. Impregnasi basah Fe3+ ke dalam MCM-41-tersililasi dapat mengakibatkan substitusi isomorfis Fe3+ menggantikan Si4+ pada jaringan silikat dan juga  menghasilkan nanopartikel oksida besi diluar jaringan silikat, yaitu mengisi sebagian pori MCM-41-tersililasi.
Functionalization of Fe3O4/SiO2 with N-(2-Aminoethyl)-3-aminopropyl for Sorption of [AuCl4]- Nuryono, Nuryono; Syukur, Mighfar; Kuncaka, Agus; Sakti, Satya Candra Wibawa
Indonesian Journal of Chemistry Vol 16, No 2 (2016)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (395.514 KB) | DOI: 10.22146/ijc.21155

Abstract

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) Hastuti, Sri; Nuryono, Nuryono; Kuncaka, Agus
Indonesian Journal of Chemistry Vol 15, No 2 (2015)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (322.821 KB) | DOI: 10.22146/ijc.21203

Abstract

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

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (7905.66 KB) | DOI: 10.22146/ijc.21950

Abstract

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.