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Indonesian Journal of Chemistry

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Published by Universitas Gadjah Mada

ISSN : 14119420 EISSN : 24601578 DOI : -

Core Subject : Science, Engineering,

Chemical Engineering, Chemistry & Bioengineering Chemistry

Indonesian Journal of Chemistry is an International, peer-reviewed, open access journal that publishes original research articles, review articles, as well as short communication in all areas of chemistry including applied chemistry. The journal is accredited by The Ministry of Research, Technology and Higher Education (RISTEKDIKTI) No : 21/E/KPT/2018 (in First Rank) and indexed in Scopus since 2012. Since 2018 (Volume 18), Indonesian Journal of Chemistry publish four issues (numbers) annually (February, May, August and November).

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Articles 1,981 Documents

85 86 87 88 89

Mesh-Assisted Laser-Induced Plasma Spectroscopy Using Pulse Carbon Dioxide Laser for Analysis of Powder Material by Confining the Powder in a Hole and Employing a Condensation Technique Ali Khumaeni; Asep Yoyo Wardaya; Heri Sugito; Nasrullah Idris; Kiichiro Kagawa
Indonesian Journal of Chemistry Vol 19, No 3 (2019)
Publisher : Universitas Gadjah Mada

Analysis of impurity in powder samples has been made by using metal-assisted laser-induced plasma spectroscopy utilizing a pulsed CO2 laser. Various powders including food powder, supplement powder, baby powder, and medicine powder were employed as sample materials. Experimentally, the powder sample was tightly put in a hole made on a metal plate and a metal mesh was placed on the powder surface. A pulse CO2 laser (10.6 μm, 1500 mJ) was irradiated on the powder surface passing through the metal mesh. Luminous plasma was induced by mesh just above the mesh when a part of laser energy attacked the mesh. The other part of laser energy impinged the powders and ablated fine particles of powder to the plasma to be atomized and excited. Identification and analysis of elements in powder were successfully conducted. A linear calibration curve of Cu in baby powder has been demonstrated with an intercept zero, certifying that the present technique was a high possibility to be employed for semi-quantitative analysis of elements in powder material. It was proved that by applying the present technique and employing a condensation technique, the detection sensitivity of Cr impurity in the powder sample increased about twenty times compared to the case without condensation. The limit of detection of Cr in rice powder sample was 25 mg/kg. The proposed method was very convenient for the identification and analysis of elements in the powder sample.

A Simple Pre-concentration Method for the Determination of Nickel(II) in Urine Samples Using UV-Vis Spectrophotometry and Flame Atomic Absorption Spectrometry Techniques Ahmed Fadhil Khudhair; Mouyed Khudhair Hassan; Hasan F. Alesary; Ahmed S. Abbas
Indonesian Journal of Chemistry Vol 19, No 3 (2019)
Publisher : Universitas Gadjah Mada

The cloud point technique was effectively utilized for extraction and pre-concentration of nickel(II) in urine samples before measurement by UV-Vis spectrophotometer and AAS techniques. The metal response to a para-aminophenol (PAP) reagent in a non-ionic surfactant Triton X-114 medium was to form the Ni-PAP complex. The adopted concentration for PAP, concentration of Triton X-114, pH effect and water bath temperature, incubation time, salt effect, and interference effects were all optimized. The calibration curve was linear over the range of (0.0625–1.25) mg L–1 with a correlation coefficient r2 of 0.9682 for the UV-Vis spectrophotometer at a λmax of 629 nm. The limit of detection was 0.005 mg/L. The relative standard deviation for six replicates was 1.07%. This method was applied successfully to determine copper (II) concentrations in 44 urine samples of occupational worker samples as determined by UV-Vis spectrophotometry and FAAS techniques.

Simulation of Melt Viscosity Effect on the Rate of Solidification in Polymer Jaka Fajar Fatriansyah; Hanindito Haidar Satrio; Muhammad Joshua Yuriansyah Barmaki; Arbi Irsyad Fikri; Mochamad Chalid
Indonesian Journal of Chemistry Vol 19, No 2 (2019)
Publisher : Universitas Gadjah Mada

Phase field model has been successfully derived from ordinary metal phase field equation to simulate the behavior of semi-crystalline polymer solidification phenomenon. To obtain the polymer phase field model, a non-conserved phase field equation can be expanded to include the unique polymer parameters, which do not exist in metals, for example, polymer melt viscosity and diffusion coefficient. In order to expand this model, we include free energy density and non-local free energy density based on Harrowel-Oxtoby and Ginzburg-Landau theorem for polymers. The expansion principle for a higher order of binary phase field parameter was employed to obtain fully modified phase field equation. To optimize the final properties of the products, the solidification phenomenon in polymers is very important. Here, we use our modified equation to investigate the effect of melt viscosity on the rate of solidification by employing ordinary differential equation numerical methods. It was found that the rate of solidification is related to the melting temperature and the kinetic coefficient.

Hydrotreating of Sunan Candlenut (Reutealis trisperma Airy Shaw) Oil by Using NiMo-γAl2O3 as Renewable Energy Daliya Indra Setiawan; Tun Tedja Irawadi; Zainal Alim Mas’ud
Indonesian Journal of Chemistry Vol 19, No 1 (2019)
Publisher : Universitas Gadjah Mada

Hydrotreating process of Sunan candlenut oil by using NiMo-γAl2O3 catalyst has been successfully investigated. Preparation of NiMo-γAl2O3 catalyst by using dipping impregnation method generated catalyst used for hydrotreating process. This method consists of three stages: support activation, impregnation, and calcination. This factors influencing the process including temperature, pressure, and the ratio of Sunan candlenut oil to the H2 gas factor were examined. The hydrotreating product of fuel similar to oil was obtained at a minimum temperature of 380 °C, a pressure of 30–60 bar, and the ratio of the sample to H2 gas of 0.5–1. The diesel fuel from physical properties range for the density of 0.82–0.86 g/cm3, and kinematic viscosity of 2–6 cSt have been fulfilled by hydrotreating result. Gasoline, naphtha, diesel oil, and gas oil products of Sunan candlenut oil were obtained by distillation from hydrotreating process. Sunan candlenut oil fuel qualified fuel requirement.

Study on Growth Mechanism of Cu Nanowires and Its Application as Transparent Conducting Electrode Dedi Mardiansyah; Kuwat Triyana; Harsojo Harsojo
Indonesian Journal of Chemistry Vol 19, No 1 (2019)
Publisher : Universitas Gadjah Mada

Cu nanowires (CuNWs) were synthesized in an aqueous solution at low temperature using ethylenediamine (EDA) as a capping agent and hydrazine as a reducing agent. This study investigated the growth of mechanism CuNWs and fabricated the transparent conducting electrode. For the growth mechanism of CuNWs, the study was conducted with an optical microscope, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction (XRD). The performance of the transparent conducting electrode was studied with UV-Vis spectrometer and IV meters. CuNWs growth from Cu nanoparticles (CuNPs) in the solution. Transparent conducting electrode gave a sheet resistance of 48.8 Ohm/sq and the transmittance of 52.63%. The understanding of the growing mechanism of Cu nanowires is important for the development of CuNWs for alternative application as a transparent conducting electrode.

Response Surface Method Application in Tofu Production Liquid Waste Treatment Hefni Effendi; Romi Seroja; Sigid Hariyadi
Indonesian Journal of Chemistry Vol 19, No 2 (2019)
Publisher : Universitas Gadjah Mada

Liquid waste of tofu production has a high content of organic matter which can lead to a decrease in water quality. This study was aimed to obtain an optimal combination of duration and waste concentration in tofu liquid waste treatment using Chrysopogon zizanioides. Response surface method using Design Expert 7.0 software was applied to optimize combination response of duration (3, 9, 15 days) and waste concentration (20, 40, 60%), aided by Design Expert 7.0 software. The optimum treatment was 15 days with 20% waste concentration, reducing 55.48% of COD, 37.86% BOD, 93.51% TSS, 87.86% Turbidity, increasing DO to 7.2 mg/L and pH to 7.2.

Sorption Mechanism and Performance of Peat Soil Humin for Methylene Blue and p-Nitrophenol Sri Juari Santosa; Eko Sri Kunarti; Nurul Hidayat Aprilita; Beti Wulandari; Dhian Nuri Bawani
Indonesian Journal of Chemistry Vol 19, No 1 (2019)
Publisher : Universitas Gadjah Mada

The responsible mechanism and performance of peat soil humin for the sorption of methylene blue (MB) and p-nitrophenol (p-NP) have been investigated. Humin was obtained from peat soil of Siantan, West Kalimantan, Indonesia, after removing the content of humic and fulvic acids into a NaOH solution using the recommended procedure of International Humic Substances Society (IHSS). The obtained humin was then purified by rigorous stirring in a mixed solution of HCl 0.1 M and HF 0.3 M. Ash content in humin after the purification abruptly decreased from 36.84 to 1.26 wt.% indicating that minerals and other inorganic impurities were mostly removed. Phenolic –OH and carboxyl (–COOH) functional groups contributing to the acidity of humin were in the level of 3.44 and 2.10 mmol/g, respectively. At optimum medium pH of 6.20 for MB and 7.00 for p-NP, –COO– as the deprotonated product of –COOH was the most responsible active site in sorbing MB and p-NP through electrostatic interaction and hydrogen bonding, respectively. The homogeneity of –COO– as the active site for the sorption of MB and p-NP implied that the surface of humin sorbent was energetically uniform and thereby the sorption of both MB and p-NP followed better the Langmuir than the Freundlich isotherm model with sorption capacity of 0.19 and 0.26 mmol/g and sorption energy of 32.92 and 27.27 kJ/mol, respectively.

Photocatalytic Degradation of Amoxicillin Using UV/Synthesized NiO from Pharmaceutical Wastewater Davoud Balarak; Ferdos Kord Mostafapour
Indonesian Journal of Chemistry Vol 19, No 1 (2019)
Publisher : Universitas Gadjah Mada

The nano nickel(II) oxide (NiO) was synthesized by sol-gel method and used for degradation of Amoxicillin (AMO) from pharmaceutical wastewater. In this laboratory study, the effects of nanoparticle dose (0.25–2 g/L), reaction time (10–120 min), initial antibiotic concentration (25–200 mg/L) and lamp power (15 W) on AMO removal efficiency were assessed in a batch photocatalytic reactor. Antibiotic concentration in output was measured by the spectrophotometer at the maximum wavelength of 280 nm. The optimum nano NiO dose was obtained to be 0.2 g/L. In this study, the removal efficiency decreased with increasing the concentration of AMO. Under optimal conditions of concentration, the removal efficiency was 96%. It was found that increasing the exposure time to UV increased the rate of AMO degradation in solution. The results also showed that the photo-degradation reaction approximately follows the pseudo-first-order kinetics with constant rates of 0.084, 0.074 and 0.046 min-1 for concentrations of 25, 50 and 100 mg/L, respectively. On the basis of the obtained results, it can be concluded that UV/NiO photocatalytic process can efficiently remove AMO from pharmaceutical wastewater.

A Novel Molecular Imprint Polymer Synthesis for Solid Phase Extraction of Andrographolide Hemavathi Krishnan; A.K.M. Shafiqul Islam; Zainab Hamzah; Pubalan Nadaraja; Mohd Noor Ahmad
Indonesian Journal of Chemistry Vol 19, No 1 (2019)
Publisher : Universitas Gadjah Mada

Penggunaan polimer yang dicetak secara molekuler untuk ekstraksi mikro fase padat (SPME) dari senyawa bioaktif semakin populer. Ketertarikan pada proses ekstraksi andrographolide yang efisien dari pabrik meningkat karena aplikasi terapetiknya yang luas. Dalam penelitian ini, MIP andrographolide yang dicetak dibuat dengan metode polimerisasi presipitasi menggunakan teknik non-kovalen untuk digunakan sebagai bahan sorben untuk ekstraksi fase padat dari senyawa bioaktif. Perangkat lunak HyperChem 8.0.10 digunakan untuk menyelidiki dan mengoptimalkan template dan rasio monomer fungsional dalam sistem pra-polimerisasi untuk mensintesis polimer yang dicetak. Pemodelan molekul memberikan informasi tentang interaksi molekuler dan energi bebas Gibbs dari kompleks pra-polimerisasi. Berdasarkan studi komputasi, andrografolida, asam metakrilat (MAA) dan etilen glikol dimetakrilat (EGDMA) digunakan sebagai templat, monomer fungsional, dan cross-linker, masing-masing pada rasio 1: 3: 20. MIP dikarakterisasi oleh studi kinetik dan faktor pencetakan. Parameter yang mengikat untuk pengakuan andrografolida dipelajari dengan menggunakan model isoterm adsorpsi Langmuir, Freundlich dan Langmuir-Freundlich. MIP Andrographolide berisi jumlah situs pengikatan maksimum dengan kapasitas adsorpsi 149,59 μg / g. Data eksperimental SPME paling sesuai dengan model isoterm Langmuir-Freundlich dengan nilai R2 0,997. Penelitian ini menunjukkan bahwa MIPs yang disiapkan oleh presipitasi polimerisasi memberikan kemampuan ekstraksi yang baik menggunakan metode SPME. 20 rasio. MIP dikarakterisasi oleh studi kinetik dan faktor pencetakan. Parameter yang mengikat untuk pengakuan andrografolida dipelajari dengan menggunakan model isoterm adsorpsi Langmuir, Freundlich dan Langmuir-Freundlich. MIP Andrographolide berisi jumlah situs pengikatan maksimum dengan kapasitas adsorpsi 149,59 μg / g. Data eksperimental SPME paling sesuai dengan model isoterm Langmuir-Freundlich dengan nilai R2 0,997. Penelitian ini menunjukkan bahwa MIPs yang disiapkan oleh presipitasi polimerisasi memberikan kemampuan ekstraksi yang baik menggunakan metode SPME. 20 rasio. MIP dikarakterisasi oleh studi kinetik dan faktor pencetakan. Parameter yang mengikat untuk pengakuan andrografolida dipelajari dengan menggunakan model isoterm adsorpsi Langmuir, Freundlich dan Langmuir-Freundlich. MIP Andrographolide berisi jumlah situs pengikatan maksimum dengan kapasitas adsorpsi 149,59 μg / g. Data eksperimental SPME paling sesuai dengan model isoterm Langmuir-Freundlich dengan nilai R2 0,997. Penelitian ini menunjukkan bahwa MIPs yang disiapkan oleh presipitasi polimerisasi memberikan kemampuan ekstraksi yang baik menggunakan metode SPME. MIP Andrographolide berisi jumlah situs pengikatan maksimum dengan kapasitas adsorpsi 149,59 μg / g. Data eksperimental SPME paling sesuai dengan model isoterm Langmuir-Freundlich dengan nilai R2 0,997. Penelitian ini menunjukkan bahwa MIPs yang disiapkan oleh presipitasi polimerisasi memberikan kemampuan ekstraksi yang baik menggunakan metode SPME. MIP Andrographolide berisi jumlah situs pengikatan maksimum dengan kapasitas adsorpsi 149,59 μg / g. Data eksperimental SPME paling sesuai dengan model isoterm Langmuir-Freundlich dengan nilai R2 0,997. Penelitian ini menunjukkan bahwa MIPs yang disiapkan oleh presipitasi polimerisasi memberikan kemampuan ekstraksi yang baik menggunakan metode SPME.

Effect of Free Fatty Acid Pretreatment to Yield, Composition and Activation Energy in Chemical Synthesis of Fatty Acid Methyl Ester Nor Saadah Mohd Alias; Harumi Veny; Fazlena Hamzah; Noorhaliza Aziz
Indonesian Journal of Chemistry Vol 19, No 3 (2019)
Publisher : Universitas Gadjah Mada

Transesterification of waste cooking oil (WCO) for fatty acid methyl ester synthesis using calcium oxide (CaO) as a catalyst with absence and presence of free fatty acid (FFA) pretreatment (untreated and pretreated) prior to reaction have been investigated. The preliminary study was started from theoretical stoichiometric amount molar ratio of methanol to oil. This preliminary experiment showed that indeed, in transesterification with the chemical catalyst the molar ratio of methanol to oil should be exceeding the theoretical stoichiometric molar ratio, due to the fast reversible reaction. The highest FAME content of 81% was achieved at a temperature of 75 °C with pretreated FFA. The composition of methyl ester with pretreated FFA was affected by temperature, where increasing temperature leads to increasing of methyl oleate as major methyl ester in the product. The relation of temperature dependence was further studied by Arrhenius law correlation. It is shown that activation energy was affected by pretreatment of fatty acid. The activation energy (Ea) of transesterification with untreated and pretreated free fatty acid were found as ± 16 kJ/mol and ± 68 kJ/mol, respectively. Unlike untreated FFA, the Ea of transesterification with pretreated FFA was within the range of activation energy for transesterification for the base catalyst. This study showed that methyl ester synthesis was best obtained when FFA was pretreated prior to transesterification. In addition, WCO is a potential feedstock for biodiesel production since it is biodegradable, economic, environmentally friendly and abundantly available.

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