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Indonesian Journal of Chemistry

ijc
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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

77 78 79 80 81

The Utilization of Nitrogen Gas as a Carrier Gas in the Determination of Hg Ions Using Cold Vapor-Atomic Absorption Spectrophotometer (CV-AAS) Aman Sentosa Panggabean; Subur P Pasaribu; Farida Kristiana
Indonesian Journal of Chemistry Vol 18, No 2 (2018)
Publisher : Universitas Gadjah Mada

The research about utilization of nitrogen gas as a carrier gas in the determination of Hg ions by using Cold Vapor-Atomic Absorption Spectrophotometer (CV-AAS) method has been conducted. To optimize the measurement results, several parameters that affect hydride generator have been studied. Some specified important parameters are SnCl2 concentration as reductant, acid concentration, and the analytical performance such as repeatability and reproducibility (% RSD), linearity (r), limits of detection (LOD) and limits of quantitation (LOQ), and accuracy have been studied. The results of the research showed that the nitrogen gas can be used instead of argon gas as a carrier gas. It was shown by the repeatability values as % RSD < 2/3 CV Horwitz values, the LOD was 0.0338 µg/L and the LOQ was 0.0838 µg/L. The accuracy of this method was well shown by a recovery percentage was 102.24%. Based on the result of this research, the nitrogen gas can be used as a carrier gas for the determination of Hg ions by using the CV-AAS method with valid results.

Synthesis of Ce-Mesoporous Silica Catalyst and Its Lifetime Determination for the Hydrocracking of Waste Lubricant Wega Trisunaryanti; Triyono Triyono; Iip Izul Falah; Andreas David Siagian; Muhammad Fajar Marsuki
Indonesian Journal of Chemistry Vol 18, No 3 (2018)
Publisher : Universitas Gadjah Mada

The synthesis of Ce/mesoporous silica (Ce/MS) and its lifetime determination for the hydrocracking of waste lubricant has been carried out. The MS was synthesized using tetraethyl orthosilicate (TEOS) and gelatin extracted from bovine bone as a template. Cerium was impregnated onto the MS by wet impregnation method using Ce(NO3)3.6H2O. The MS and Ce/MS were then characterized by means of acidity using ammonia base vapor adsorption, Fourier Transform Spectrophotometer (FTIR), Transmission Electron Microscope (TEM), Scanning Electron Microscope-Energy Dispersive X-ray Spectrometer (SEM-EDX), and surface area analyzer (SAA) based on the BET and BJH equation. The Ce/MS catalyst was tested in hydrocracking of waste lubricant in three runs. Lifetime of Ce/MS catalyst was determined using a linear regression of the liquid product yields vs hydrocracking time. The Ce/MS catalyst showed an acidity of 2.79 mmol/g, BJH desorption pore diameter of 3.84 nm, BET surface area of 246.55 m2/g, and total pore volume of 0.44 cm3/g. The yield of liquid product obtained from hydrocracking of waste lubricant using the Ce/MS catalyst for the first, second, and third runs was 21.42, 17.23 and 10.54 wt.%, respectively for 2.5 h per each run. Lifetime of Ce/MS catalyst in hydrocracking of waste lubricant was 12.54 h.

Investigation on the Effect of Addition of Fe3+ Ion into the Colloidal AgNPs in PVA Solution and Understanding Its Reaction Mechanism Roto Roto; Marcelina Marcelina; Nurul Hidayat Aprilita; Mudasir Mudasir; Taufik Abdillah Natsir; Bella Mellisani
Indonesian Journal of Chemistry Vol 17, No 3 (2017)
Publisher : Universitas Gadjah Mada

Analysis of Fe3+ ion present in aqueous solutions is always of interests. Recently, this ion has been analyzed by colorimetric methods using colloid of silver nanoparticles (AgNPs) in capping agents of polymers. The reaction mechanism between AgNPs and Fe3+ is still subject to the further investigation. In this work, 1,10-phenanthroline was used to probe the reaction mechanism between AgNPs and Fe3+ ion in the solution. The colloids of AgNPs were prepared in the polyvinyl alcohol (PVA) solution and reacted with Fe3+. The colloid surface plasmon absorbance decreases linearly along with the increase in Fe3+ concentration. The addition of 1,10-phenanthroline to mixture changes the solution to red, indicating that the reaction produces Fe2+. This suggests that the reduction of the AgNPs absorbance is the result of oxidation of the Ag nanoparticles along with the reduction of Fe3+.

Synthesis and Photoactivity of Fe3O4/TiO2-Co as a Magnetically Separable Visible Light Responsive Photocatalyst Eko Sri Kunarti; Indriana Kartini; Akhmad Syoufian; Karolina Martha Widyandari
Indonesian Journal of Chemistry Vol 18, No 3 (2018)
Publisher : Universitas Gadjah Mada

Synthesis of magnetic photocatalyst, Fe3O4/TiO2-Co, with characterization and photoactivity examination have been conducted. The synthesis was initiated by preparation of Fe3O4 particles using coprecipitation method. The Fe3O4 particles were then coated with TiO2-Co at a various ratio of Fe3O4:TiO2 and concentration of Co(II) dopant. The Fe3O4/TiO2-Co was characterized by FTIR, XRD, TEM, SEM-EDX, VSM, and SR UV-visible methods. Photoactivity of the Fe3O4/TiO2-Co was carried out using methylene blue as a target molecule in degradation reaction within a batch system. By using optimum conditions, the degradation of methylene blue solution was performed under exposure to UV, visible light and dark condition. Results showed that the Fe3O4/TiO2-Co formation was confirmed by the presence of Fe3O4 and anatase diffraction peaks in the X-ray diffractogram. SR UV-Vis spectra indicated that the Fe3O4/TiO2-Co was responsive to visible light. Band gap energy of the Fe3O4/TiO2-Co with dopant concentration of 1; 5; 10 and 15% were 3.22; 3.12; 3.09 and 2.81 eV, respectively. The methylene blue solution can be well photodegraded at a pH of 10 for 210 min. The Fe3O4/TiO2-Co has the highest ability to methylene blue photodegradation with dopant concentration of 10% gave degradation yield of 80.51 and 95.38% under UV and visible irradiation, respectively.

Integrative Assessment of Pb and Cd Pollution in Porong Estuaries Using Sediment Chemistry, Bioavailability, and Bioconcentration Factor Barlah Rumhayati; Catur Retnaningdyah
Indonesian Journal of Chemistry Vol 18, No 3 (2018)
Publisher : Universitas Gadjah Mada

The aims of the research were to perform an integrative assessment of high metal pollution in Porong Estuary by determining (i) the distribution of heavy metals fraction in sediment, (ii) the potential risk of sediment to the metal bioavailability, and (iii) the bioaccumulation factor of heavy metals in benthic. Fractionation of heavy metals in the sediments was carried out by the European Community Bureau of Reference (BCR) sequential extraction method. The potential risk of sediment was determined from RAC (risk assessment code) value. Bioconcentration factor was determined based on the ratio of the concentration of heavy metals in benthic to the concentration of bioavailable metals from sediments. Heavy metal concentrations were measured using AAS. The results showed that non-resistant Pb and Cd was higher than resistant fractions. As a non-resistant fraction, Pb was found mostly as fraction 2, i.e., metal fraction adsorbed on the surface of the iron oxy/hydroxide sediment (34.5 ± 4.9%). Cd was more prevalent as fraction 3, i.e., an organic bound fraction (29.0 ± 1.8%). Furthermore, Porong Estuary sediments had medium risk for contributing the bioavailable Cd in the water bodies based on the RAC (15.6 ± 1.8%). Based on the bioconcentration factor, accumulation of Cd and Pb was low (48.00 ± 7.62% for BCF-Cd and 32.29 ± 6.90% for BCF-Pb). Based on the results above, it could be concluded that the Porong Estuary water bodies have not been polluted by Pb and Cd released from the aquatic sediment.

Fixed-Bed Column Studies for the Removal of Congo Red Using Simmondsia chinesis (Jojoba) and Coated with Chitosan Amina Abdel Meguid Attia; Mona Abdel Hamid Shouman; Soheir Abdel Atty Khedr; Nevin Ahmed Hassan
Indonesian Journal of Chemistry Vol 18, No 2 (2018)
Publisher : Universitas Gadjah Mada

The goal of this article describes the potential of utilizing jojoba leaves and also modified with chitosan as an efficient adsorption materials for Congo red dye removal in a fixed-bed column. Inlet dye concentration, feed flow rate and bed height had a great influence on determining the breakthrough curves. The percentage dye removal was found to be approximately 69% of coated jojoba leaves with flow rate 3 mL/min, initial concentration 50 mg/L and 4 cm bed height. The dye uptake capacity at equilibrium (qe) for coated jojoba leaves showed higher values than that found for jojoba leaves. On this basis, this implies that the amino groups played an important role during the adsorption process. Breakthrough curves were satisfactorily in good agreement with both Thomas and Yoon-Nelson models based on the values of correlation coefficient (R2 ≥ 96).This study serves as a good fundamental aspect of wastewater purification on jojoba leaves as a novel adsorbent for the uptake of Congo red dyes from aqueous solution in a column system.

Characteristics of Trace Elements in Volcanic ash of Kelud Eruption in East Java, Indonesia Diah Dwiana Lestiani; Revi Apryani; Linda Lestari; Muhayatun Santoso; Eko Prabowo Hadisantoso; Syukria Kurniawati
Indonesian Journal of Chemistry Vol 18, No 3 (2018)
Publisher : Universitas Gadjah Mada

The eruption of Mount Kelud that occurred on February 13, 2014, ejected a huge plume of ash and sand exceeding 26 km into the air which moved west over the island. The elements content in volcanic ash is important information for further study such as the possibility to utilize the ash. In this study, the volcanic ashes collected from four affected areas in Java were analyzed using neutron activation analysis (NAA) with HPGe detector and X-ray fluorescence. Method validation was applied using the standard reference material SRM NIST 2711a Montana Soil with recovery and accuracy in a good agreement for all elements. The analysis results of volcanic ashes showed a wide range of elements, major elements Al, Ca, Fe, K, Mg, Mn, Na, Si and Ti, trace elements As, Cd, Cu, Co, Cr, V, Zn, Hf, Th and U, and rare earth elements were identified. The results showed heavy metals As, Cd, Cu, Co, Cr, and Pb were ranged 3.23–4.42, 17.63–24.09, 49.26–77.10, 10.86–16.03, 11.19–17.79 and 31.4–42.7 mg/kg, respectively, while rare earth elements such as Ce, Eu, La, and Sm were 9.84–18.43, 0.73–1.02, 2.25–5.66 and 1.34–2.63 mg/kg respectively. Comparison with other volcanic ashes from Indonesia such as Merapi and Sinabung and world volcanic ashes were applied. The results of the characteristic of elements in Kelud volcanic ash would be valuable information as reference data for their potential utilization.

Optimization on Supercritical CO2 Extraction Process to Improve the Quality of Patchouli Oil by Response Surface Methodology Approach Edi Priyo Utomo; Marina Marina; Warsito Warsito; Egi Agustian
Indonesian Journal of Chemistry Vol 18, No 2 (2018)
Publisher : Universitas Gadjah Mada

Until now, the patchouli oil is the largest commodity export of essential oil for Indonesia. But the price of patchouli oil is often unstable due to the quality of oil which fluctuates depending on the components. To improve the performance and quality of patchouli oil had been carried out the purification process using supercritical CO2 fluid extraction method. Optimization conditions of the extraction process using the approach of Response Surface Methodology (RSM) and the influence of independent variables include temperature (35–45 °C), pressure (80–150 atm) and the time of extraction (60–300 min), and then evaluated using a Box-Behnken Design (BBD). Analysis of the components in the extract was carried out by using GC-MS and GC-FID to detect the changes of compositions of the components containing the oil before and after the extraction process. The optimum condition of supercritical extraction within experimental range of the studied variables was at 38 °C, 146.35 atm and 74 min for predicted oil yield of 6.41% and at 41.45 °C, 135.17 atm and 252.62 min and the predicted patchouli alcohol content was 25.34%. The extracted oil is enriched with the main components such as patchouli alcohol compared to the original patchouli oil. The results of RSM evaluation showed consistency between the variables contained in the experiment and the prediction.

The Synthesis and Stability Study of Silver Nanoparticles Prepared by Using p-Aminobenzoic Acid as Reducing and Stabilizing Agent Dian Susanthy; Sri Juari Santosa; Eko Sri Kunarti
Indonesian Journal of Chemistry Vol 18, No 3 (2018)
Publisher : Universitas Gadjah Mada

A study to examine the performance of p-aminobenzoic acid as both reducing agent for silver nitrate to silver nanoparticles (AgNPs) and stabilizing agent for the formed AgNPs has been done. The synthesis of AgNPs was performed by mixing silver nitrate solution as precursor with p-aminobenzoic acid solution and heating it in a boiling water bath. After the solution turned to yellow, the reaction stopped by cooling it in tap water. The formed AgNPs were analyzed by using UV-Vis spectrophotometry to evaluate their SPR absorption in wavelength range of 400–500 nm. The synthesis process was highly depend on the pH, reaction time, and mole ratios of the reactants. The synthesis only occur in pH 11 and at reaction time 30 min, the particle size of the formed AgNPs was 12 ± 7 nm. Longer reaction time increased the reducing performance of p-aminobenzoic acid in AgNPs synthesis but decreased its stabilizing performance. The increase of silver nitrate amount relative to p-aminobenzoic acid in the synthesis increased the reducing and stabilizing performance of p-aminobenzoic acid and the optimum mole ratio between AgNO3 and p-aminobenzoic acid was 5:100 (AgNO3 to p-aminobenzoic acid).

Functionalization of Chitosan with Maleic Anhydride for Proton Exchange Membrane Muhammad Ridwan Septiawan; Dian Permana; Sitti Hadijah Sabarwati; La Ode Ahmad; La Ode Ahmad Nur Ramadhan
Indonesian Journal of Chemistry Vol 18, No 2 (2018)
Publisher : Universitas Gadjah Mada

Chitosan was modified by maleic anhydride, and it was then functionalized using heterogeneous and blending method to obtain the membrane. The results of the reaction between chitosan with maleic anhydride were signed by the new peak appears around 1475 cm-1 which attributed to C=C bending of alkene. The new peak also appears at 1590 cm-1 which attributed to N-H bending of amide. Chitosan-maleic anhydride membranes show microstructure of chitosan membrane with high porous density and rigidity while chitosan-maleic anhydride membranes have clusters. In addition, the thermal tenacity of membranes reached 500 °C. Modified membrane by heterogeneous and blending method have higher water uptake, ion exchange capacity, and proton conductivity than chitosan membrane. Moreover, the blending method is much more effective than the heterogeneous method that can be exhibited from ion exchange capacity and proton conductivity values of 1.08–6.38 meq g-1 and 1x10-3–1x10-2 S cm-1, 0.92–2.27 meq g-1 and 1.53x10-4–3.04x10-3 S cm-1, respectively. The results imply that modification of chitosan membrane with the addition of maleic anhydride using heterogeneous and blending method can be applied to proton exchange membrane.

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