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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 1,956 Documents

122 123 124 125 126

Determination of Total Flavonoid Content in Medicinal Plant Leaves Powder Using Infrared Spectroscopy and Chemometrics Lestyo Wulandari; Bayu Dwi Permana; Nia Kristiningrum
Indonesian Journal of Chemistry Vol 20, No 5 (2020)
Publisher : Universitas Gadjah Mada

Flavonoid is phenolic compounds consisting of fifteen carbon atoms and is commonly found in plants. Infrared (IR) spectroscopy combined with chemometrics, has been developed for a simple analysis of flavonoid in the medicinal plant leaves powder. IR spectra of selected medicinal plant powder were correlated with flavonoid content using chemometrics. The chemometric methods used for calibration analysis were Partial Least Square (PLS), Principal Component Regression (PCR), and Support Vector Regression (SVR). After the calibration model was formed, it was then validated using Leave-One-Out-Cross-Validation (LOOCV) and 2-fold cross-validation. In this study, the PLS of the Near-infrared (NIR) calibration model showed the best calibration with R-Square and RMSEC values of 0.9676524 and 0.0978202, respectively. The LOOCV of PLS of the NIR calibration model has the R-square and RMSE values of 0.9850164 and 0.067663, respectively. The 2-fold cross-validation gave the R-square and RMSE values of 0.9857071 and 0.2104665, respectively. PLS of the NIR calibration model was further used to predict unknown flavonoid content in commercial samples. The significance of flavonoid content that has been measured by NIR and UV-Vis spectrophotometry was evaluated with paired samples T-test. The flavonoid content that has been measured with both methods gave no significant difference.

Coating of Pd and Co on Mordenite for a Catalyst of Hydrotreating of Cashew Nut Shell Liquid into Biofuel Maya Tri Hapsari; Wega Trisunaryanti; Iip Izul Falah; Media Laila Permata
Indonesian Journal of Chemistry Vol 20, No 5 (2020)
Publisher : Universitas Gadjah Mada

The catalytic activity of Co and Pd loaded on mordenite (MOR) was evaluated in the hydrotreatment of cashew nut shell liquid (CNSL) into biofuel. Metals were loaded into MOR as support via wet impregnation process. The Co content was varied as 2, 4, and 6 wt.% to produce Co(1)/MOR, Co(2)/MOR, Co(3)/MOR catalysts. The micro-mesoporous structure of the catalyst was confirmed by XRD, SEM, TEM, FTIR, and N2 adsorption-desorption measurement. AAS were used to analyze the amount of metal that is successfully loaded in the catalysts. Hydrotreating of the CNSL was conducted in a semi-batch reactor at 450 °C with hydrogen flow (20 mL/min) for 2 h. The liquid product was analyzed using GC-MS. The activity of Co/MOR was compared with the activity of Pd/MOR as a noble metal. The result of the hydrotreatment process showed a decrease of liquid product in the sequence of Co(3)/MOR > Co(2)/MOR > Pd/MOR > Co(1)/MOR > MOR. The Co(3)/MOR catalyst exhibited the highest conversion of liquid hydrocarbon than the others (61.8 wt.%), comprising predominantly by gasoline compounds with over 25.21 wt.% conversion.

Synthesis of Activated Carbon/Chitosan/Alginate Beads Powder as an Adsorbent for Methylene Blue and Methyl Violet 2B Dyes Margaretha Aditya Kurnia Purnaningtyas; Sri Sudiono; Dwi Siswanta
Indonesian Journal of Chemistry Vol 20, No 5 (2020)
Publisher : Universitas Gadjah Mada

The activated carbon-chitosan-alginate (KKA) beads powder was synthesized to form an adsorbent for the cationic dyes, methylene blue (MB) and methyl violet 2B (MV 2B). The aims of this research were to determine the optimum composition of KKA beads powder for the adsorption of cationic dyes and to investigate the effect of pH, adsorbent mass, contact time, and initial concentration of MB and MV 2B dyes. A desorption study was also implemented to predict the adsorption mechanisms of MB and MV 2B dyes. The KKA beads powder was prepared by mixing chitosan, Na-alginate with various variation of masses (0.6; 0.8; 1.0; and 1.2 g) and activated carbon. The KKA beads were immersed in a CaCl2 solution. The KKA beads powder was characterized using FTIR spectroscopy and SEM. The desorption study was conducted in NaCl (0.1 M and 1.0 M), ethanol (40% and 60%), and pH 4 solution. The result showed that the KKA beads powder had been successfully created, with maximum adsorption capacities of 1.34 mmol g–1 for MB and 1.23 mmol g–1 for MV 2B. The kinetics and isotherms of MB and MV dyes adsorption on the KKA beads powder followed pseudo second order kinetics model and Freundlich isotherm. The desorption study showed that 60% ethanol was the most effective desorption solution for cationic dyes.

Synthesis and Certification of Lanthanum Oxide Extracted from Monazite Sand Samin Samin; Suyanti Suyanti; Susanna Tuning Sunanti; Wisnu Ari Adi
Indonesian Journal of Chemistry Vol 20, No 6 (2020)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.44327

Synthesis and certification of lanthanum oxide extracted from monazite sand have been carried out. This research aimed to increase the added value of monazite sand and obtain the lanthanum oxide in-house certified reference material (CRM). Synthesis of lanthanum oxide consists of several stages, namely: monazite sand digestion, rare-earth elements hydroxide [REE(OH)3] precipitation, Ce separation, Nd separation, lanthanum oxalate precipitation, and calcination. Certification of lanthanum oxide was carried out by determining the average concentration of the oxides and its uncertainty from the seven accredited laboratories by the ISO 35-2006 statistical method. Two other minerals in the lanthanum oxide analyzed by the XRD method were cerium hydroxide [Ce(OH)3] and neodymium yttrium oxide fluoride (Nd2Y2O3F16). Lanthanum oxide certified contains ten oxides, with the two highest concentrations of La2O3 (91.662 ± 0.007)% and Nd2O3 (3.949 ± 0.002)%. Lanthanum oxide has met the qualification in-house CRM since it contained water less than 1%, was homogeneous, stable, and certified. La2O3 concentration in the lanthanum oxide in-house CRM from CSAT-BATAN, Indonesia was not significantly different in comparison to that from the Department of Chemical Engineering, Srinakharinwirot University, Thailand. Lanthanum oxide extracted from monazite sand can be used as reference material in determining the lanthanum oxide quality from the pilot plant process.

Hydrothermal Synthesis: Low−Temperature Subcritical Water for Ceria−Zirconia Mixed Oxides Preparation Siti Machmudah; Widiyastuti Widiyastuti; Wahyudiono Wahyudiono; Sugeng Winardi; Hideki Kanda; Motonobu Goto
Indonesian Journal of Chemistry Vol 21, No 1 (2021)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.47357

A low-temperature hydrothermal synthesis technique was employed as a medium to produce ceria−zirconia mixed oxides particles at temperatures of 200–300 °C and pressure of 10 MPa in a batch process. At these conditions, the average crystallite sizes of ceria−zirconia mixed oxides increased slightly with increasing reaction temperature when the feed solution containing ceria and zirconia with a ratio of 1:1 was fed. SEM images illustrated that the morphologies of the ceria−zirconia mixed oxides particles were spherical and spherical−like with a diameter of around 100 nm. The EDX spectrum indicated that the signal corresponding to the ceria and the zirconia elements at 5 and 2 keV, respectively, were strongly detected in the products. The XRD pattern revealed that the mixed metal oxides particle products that comprised of cerium and zirconium oxides particles with cubic and monoclinic structures, respectively, were affected by their molar content in the feed solution.

Design of Defect and Metallic Silver in Silver Phosphate Photocatalyst Using the Hydroxyapatite and Glucose Uyi Sulaeman; Suhendar Suhendar; Hartiwi Diastuti; Roy Andreas; Shu Yin
Indonesian Journal of Chemistry Vol 20, No 6 (2020)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.48647

The defect and metallic silver (Ag) in silver phosphate (Ag3PO4) photocatalyst were successfully generated using hydroxyapatite (HA) and glucose. Two steps of synthesis were done in these experiments. Firstly, the Ag/HA powder was prepared by reacting AgNO3 and HA, followed by the addition of a glucose solution. Secondly, the suspension of Ag/HA was reacted with AgNO3 aqueous solution. The yellow product of Ag/Ag3PO4 photocatalyst was produced. The products were characterized using X-Ray Diffraction (XRD), Diffuse Reflectance Spectroscopy (DRS), Scanning Electron Microscope (SEM), Brunauer–Emmett–Teller (BET) and X-ray Photoelectron Spectroscopy (XPS). The decreased ratio of O/Ag and metallic Ag formation observed by the XPS was detected as the possible defect and Ag-doping in the photocatalyst. The enhanced photocatalytic activity might be caused by the oxygen vacancy and metallic Ag in Ag3PO4 that enables the separation of photo-generated electrons and holes.

Characterization and Prediction of the Non-Bonded Molecular Interactions between Racemic Ibuprofen and α-Lactose Monohydrate Crystals Produced from Melt Granulation and Slow Evaporation Crystallization Zulfahmi Lukman; Nornizar Anuar; Noor Fitrah Abu Bakar; Norazah Abdul Rahman
Indonesian Journal of Chemistry Vol 20, No 6 (2020)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.48912

Granulation of racemic ibuprofen (±IBP) and α-lactose monohydrate (ALM) at a slightly lower (±IBP) melting point is an efficient method of binding the active pharmaceutical ingredients (API) and excipient in a binderless condition. However, the co-crystals may be formed from recrystallization of ±IBP on ALM. The objective of this study is to evaluate the tendency of co-crystal formation of granules (3:7 w/w ratio of ±IBP:ALM) by melt granulation process. Second, investigate the recovery of crystals from polyethylene glycol (PEG) 300 solutions containing ±IBP-ALM mixtures. Characterizations of the samples were performed using Fourier Transform Infrared (FTIR) spectroscopy, Differential Scanning Calorimetry (DSC) and Powder X-Ray Diffraction (PXRD) system of the ±IBP-ALM granules produced from melt crystallization and harvested crystals from PEG 300 solution which is produced using slow evaporation crystallization. Crystal analysis of solution containing ±IBP-ALM mixtures revealed that the crystals formed were not co-crystals. Molecular interactions assessment through binding prediction between ±IBP and ALM terminating surfaces was conducted using molecular modelling technique. The result showed that the favorable binding sites of ±IBP molecules were on the surfaces of (0-20), (1-10), (001) and (011) ALM crystals. Successful binding prediction by the attachment energy method has proven that the co-crystal formation between these molecules is theoretically possible.

The Use of Real-Time Polymerase Chain Reaction Combined with Specific-Species Primer for Analysis of Dog Meat DNA in Meatball Abdul Rohman; Wiranti Sri Rahayu; Sudjadi Sudjadi; Sudibyo Martono
Indonesian Journal of Chemistry Vol 21, No 1 (2021)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.48930

The presence of dog meat is a crucial issue because dog meat is non-halal meat for Muslims. The objective of this study was to design and validate species-specific primer for the identification of dog meat DNA in meatball using real-time polymerase chain reaction (real-time PCR). The specific primer targeting mitochondrial cytochrome c oxidase subunit 1 (CO1) was validated. The specific primers used were designed using Integrated DNA Technologies (IDT) software and subjected to NCBI BLAST procedure. The candidate primers were tested for specificity study using several DNAs from fresh meat of pork, chicken, beef, lamb, and rat. The method was also validated by determining several parameters of linearity, sensitivity, precision, and efficiency. The results showed that primer could amplify specifically DNA target at an optimized annealing temperature of 56.6 °C. The limit of detection (LoD) obtained was 5 ng DNA, corresponding to 2.5% of dog meat in a meatball. The repeatability evaluation, expressed with relative standard deviation (RSD), and efficiency value was in the acceptable range (RSD < 25% and efficiency (90–105%). This method was successfully used for the analysis of marketed samples. Real-time PCR can be used as a standard method in halal authentication analysis through DNA analysis.

Application of Titanium-Silica-Graphite Composite Material for Photocatalytic Process of Methylene Blue Lia Destiarti; Risya Sasri
Indonesian Journal of Chemistry Vol 20, No 6 (2020)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.48998

The use of TiO2 in the slurry system for the photocatalytic process has disadvantages. It causes the resistance of UV transmission because it is cloudy and the difficulty for obtaining the catalyst at the end of the process. Therefore, an attempt to overcome this was conducted by compositing TiO2 on SiO2. Furthermore, carbon material can be used as a support material for TiO2-SiO2, so that the mixed materials can be used as a photocatalyst. The methods for synthesis the material was a sol-gel method by varying the composition of TiO2-SiO2/graphite, which was 1:1; 1:2; and 2:1. The material obtained was characterized by FTIR, DRUV, XRD, and SEM. Photocatalytic activity of the synthesized material was tested in methylene blue solution whereas the quantitative data derived from UV-Vis spectrometry measurement. Photocatalyst activity was carried out by varying the degradation time of 30–180 min. The FTIR spectrum showed that O-H (~3400 cm–1) and C-O (~1100 cm–1) are the major groups in the synthesized materials. The value of bandgap energy (Eg) were 4.15, 4.20, 5.22, and 5.19 eV for TiO2-SiO2, TiO2-SiO2/G (1:1; 1:2; and 2:1) composites, respectively. The XRD pattern of TiO2-SiO2 showed that the highest peaks of 2q were observed at 25.32, 37.71 and 47.91°. Graphite identity appeared at 2q = 59.87°. Micrograph of SEM showed a homogenous dispersion of spherical particles in the materials. Photocatalytic test results showed that TiO2-SiO2/G with a composition of 2:1 has the highest percentage of methylene blue degradation, which reached 94% at 180 min.

Antifungal Activity of TiO2/Ag Nanoparticles under Visible Light Irradiation Nahzim Rahmat; Endang Tri Wahyuni; Adhitasari Suratman
Indonesian Journal of Chemistry Vol 21, No 1 (2021)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.49150

The doping of TiO2 by Ag(I) from [Ag(S2O3)2]3– contained in radiophotography wastewater by photoreduction method has been performed. TiO2/AgNPs photocatalyst was examined for its activity as an antifungal material for the inhibition of C. albicans in water under visible light irradiation. In the doping process, the weight of TiO2 was varied to obtain TiO2/AgNPs with different amounts of Ag. The TiO2/AgNPs samples were characterized by using FTIR, SRUV, TEM, SEM-EDX, and XRD methods. The antifungal test was carried out by disc diffusion method under visible light irradiation, wherein the amount of Ag-doped on TiO2, the dose of TiO2/AgNPs, and the irradiation time were optimized. The research results indicated that the antifungal activity of TiO2/AgNPs in inhibiting C. albicans has been successfully prepared. The highest inhibition was achieved by using 0.5 g/L of TiO2/AgNPs (I), at 5 h of irradiation time.

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