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Jurnal Riset Kimia
Published by Universitas Andalas
ISSN : 1978628X     EISSN : 24768960     DOI : -
Core Subject : Science,
Chemistry
Arjuna Subject : -
Articles 554 Documents
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Activated Carbon Addition Methods on the Pre-impregnation Process of Co-Mo in Y-Zeolite Ultra Stable: A Properties Exploration and Enhancement of Metals Loaded Hidayat, Yuniawan; Nugrahaningtyas, Khoirina Dwi; Hendrastuti, Priska Julia
Jurnal Riset Kimia Vol 12, No 2 (2021): September
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v12i2.384

Abstract

The amount of loaded Co-Mo metal on the Y-Zeolite Ultra Stable (USY) was increased by the addition of activated carbon in the pre-impregnation process. USY modification was done by adding activated carbon to USY as much as 10 wt%. The process of adding activated carbon is carried out by three methods, i.e., grinding with sucrose binder (ACU1), without sucrose (ACU2), and conducting by ball milling (ACU3). Wet impregnation method was employed to disperse the Co and Mo, sequentially. Composites were characterized using Fourier Transform Infrared (FTIR), X-ray diffraction (XRD), and surface area analyzer (SAA). Metal dispersions were observed by X-ray fluorescence (XRF). The FTIR suggests an interaction between USY and activated car-bon, while the XRD result indicated the none structural transformation of USY zeolite. The SAA analysis showed an increased total pore radius with the activated carbon addition. The XRF confirmed the increasing of total metals dispersion of 6.25% (ACU1); 5.48%(ACU2); 5.18% (ACU3); compare to USY origin with 3.28% metals loaded.
Pengembangan Metode Serbuk Daun Suji (Pleomele angustifolia N.E.Br) sebagai Identifikasi Sidik Jari Laten Sari, Sri Adelila; Nasution, Desi Heriyanti
Jurnal Riset Kimia Vol 12, No 2 (2021): September
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v12i2.406

Abstract

Fingerprint is a technology that can be used to identify a person. The dusting method is most often used on latent fingerprints because it is relatively easy and simple. However, the composition of the ingredients used in latent fingerprint powder is toxic and can be hazardous to health. This research was carried out using a new natural powder from Suji leaf as a simple, non-toxic, and cheaper. Suji leaf powder produces a green color that comes from the chlorophyll compounds contained in it. This chlorophyll compound will bind to alanine to identify latent fingerprints. The particle sizes used in this study were of 60-200 mesh. The results found that the particle sizes of 100 and 200 mesh provided good green contrast and clear visualization of the fingerprint patterns. Meanwhile, at the particle size of 60 and 80 mesh, it was found that the results were not clear visualized. The highest percentage of fingerprint patterns based on blood group, gender and ethnicity was found in form of loops. The percentage of fingerprint patterns formed based on the highest was of O 31.1; B 12.2; AB 8.8; and A 6.6 percent. The highest percentage of fingerprint patterns formed by gender were of 45.5 for women and 13.3 percent for men. The highest percentage of fingerprint patterns formed by ethnicity were Malay 21.1, Batak 20, and Javanese 17.7 percent.
Voltametri Pelucutan Anodik Menggunakan Elektroda Pasta Karbon Termodifikasi Bentonit untuk Penentuan Kadar Ion Cd(II) dalam Sayur Sawi Putih Irdhawati, Irdhawati; Titasia, Ni Kadak Nevi; Sahara, Emmy
Jurnal Riset Kimia Vol 12, No 2 (2021): September
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v12i2.417

Abstract

In this study, the measurement of Cd(II) ion by anodic stripping voltammetry technique was conducted using bentonite modified carbon paste as working electrode (CPE-B). The performance of CPE-B was compared with carbon paste electrode without bentonite (CPE) and applied for determination of Cd(II) concentration in chicory. Optimized parameters were composition of bentonite in carbon paste electrode, deposition time, deposition potential, and scan rate. Validation of measurements was observed including determination of linear concentration range, detection and quantization limits, repeatability of measurement, and percentage of recovery. The optimum composition of bentonite in CPE-B was found at 50%. Furthermore, in the optimization of measurements condition was found the optimum deposition times were 90 and 60 s, deposition potentials were -0.63 and -0.53 V, and scan rates were 15 and 20 mV/s, for CPE and CPE-B. The linear range concentration for CPE observed at 25-2000 µg/L and CPE-B was 5-50 µg/L. Limit of detection and quantization using CPE-B were 0.337 µg/L and 0.349 µg/L, lower than CPE i.e., 0.470 µg/L and 0.471 µg/L, respectively. Repeatability measurement of Cd(II) had Horwitz Ratio value less than two, and percentage of recovery was 96.73 8.33%. The level of Cd(II) ion in chicory was found at 6.98 0.40 mg/kg.
Biodecolorization of Remazol Brilliant Blue–R dye by Tropical White-Rot Fungi and Their Enzymes in The Presence of Guaiacol Anita, Sita Heris; Ningsih, Fitria; Yanto, Dede Heri Yuli
Jurnal Riset Kimia Vol 12, No 2 (2021): September
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v12i2.388

Abstract

The ability of the tropical white-rot fungi and their enzyme to decolorize synthetic dyes was investigated. Production of lignin-modifying enzymes (LMEs) from the three new isolated fungi, namely Trametes hirsuta D7, Ceriporia sp. BIOM 3, and Cymatoderma dendriticum WM01 were observed for 9 days incubation under static condition. The results showed that the LMEs production enhanced in the present of guaiacol. T. hirsuta D7 produced only laccase (Lac), with the highest activity was 22.6 U/L on the 5th-day of the cultivation. At the same time, Ceriporia sp. BIOM 3 and C. dendriticum WM01 secreted both laccases (Lac) with the activities 0.2 U/L and 1.0 U/L, respectively, and manganese peroxidase (MnP) with the activities 0.1 U/L and 1.0 U/L, respectively. Among the fungi, T. hirsuta D7 efficiently degraded 65% Remazol Brilliant Blue–R (RBBR) dye within 72 h using the only laccase. This study shows that laccase may have a major role in synthetic dyes' decolorization process, followed by MnP and LiP.
Fabrication and Characterization of Chitosan/N-Phthaloyl Composite Membrane for DMFC Application Nugraeni, Christine Dyta; Atmaja, Lukman; Hayati, Nur; Purwanto, Mochammad; Santoso, Mardi; Kusumawati, Yuli
Jurnal Riset Kimia Vol 12, No 2 (2021): September
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v12i2.408

Abstract

Modified chitosan membrane is one of the promising membranes for polymer electrolyte membrane. Chitosan/N-phthaloyl chitosan composite membranes were fabricated to obtain high proton conductivity and low methanol permeability. Membranes were fabricated by casting method and solvent evaporation. Surface morphology, mechanical analysis, methanol permeability, and proton conductivity were used to characterize the overall properties. FT-IR spectra exhibited the presence of interaction of chitosan and n-phthaloyl/chitosan. SEM analysis showed that the surface roughness of composite membrane increases as the n-phthaloyl loading increases. The highest proton conductivity of synthesized membrane is at 2.4 mS.cm-1 and is higher than pristine chitosan membrane at 1.6 mS.cm-1. Moreover, with n-phthaloyl/chitosan addition, the methanol permeability was also improved. The correlation between proton conductivity and methanol permeability in composite membranes suggests that the blend has its potential in DMFC application.
Production of Starch-Based Bioplastic from Durio zibethinus Murr Seed Using Glycerol as Plasticizer Jannah, Nanda Raudhatil; Jamarun, Novesar; Putri, Yulia Eka
Jurnal Riset Kimia Vol 12, No 2 (2021): September
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v12i2.398

Abstract

Bioplastics are bio-based plastics from natural resources, made to replace conventional plastics. The utilization of biopolymers in bioplastics provide a faster degradation compared to petroleum-based plastics. Starch-based bioplastic from mixing Durio zibethinus Murr starch and glycerol as plasticizer have been conducted. In this research, the concentration of glycerol has been varied to study the effect on starch-based bioplastics mechanical properties. The tensile strength for Durio zibethinus Murr starch-based bioplastic with 20% glycerol was 50.28 MPa with 13.3% elongation. The functional group found on the Fourier transform infrared spectroscopy (FTIR) spectra indicated the presence of O-H stretch, C-H stretch, C=O stretch, and C-O stretch which stated the formation of bioplastic. The image results gained from scanning electron microscope (SEM) showed that the morphology surface of bioplastic was less homogenous and rough. The soil burial test for biodegradability showed Durio zibethinus Murr starch-based bioplastic achieved 38.9% weight loss in a 5-day observation.
Penentuan Kandungan Antioksidan Total pada Infusa Selada Hijau (Lactuca sativa L.) Hidroponik dan Konvensional secara Spektrofotometri dengan Modified Phenantroline Method (MPM) Yefrida, Yefrida; Refilda, Refilda; Hamidah, Nofi; Rosman, Widuri
Jurnal Riset Kimia Vol 13, No 1 (2022): March
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v13i1.492

Abstract

Green lettuce is a vegetable that is widely consumed in Indonesia. These vegetables come from conventional and hydroponic farming. This study aims to compare the antioxidant content of these two types of vegetables. This vegetable is extracted by the infundation method. The extract obtained was determined for its antioxidant content by the MPM method. This method was validated by using parameter LoD, LoQ, linearity, precision and accuracy. The results showed that this method was valid for determining the total antioxidant content in conventional and hydroponic green lettuce samples. The total antioxidant content in conventional and hydroponic green lettuce samples was 2.68 ± 0.65 mg aa/g FW and 1.67 ± 0.40 mg AA/g FW, respectively. T test stated that the antioxidant content of the two samples was significantly different.
Black Water Purification by Activated Carbon from Ilalang Weeds (Imperata cylindrica) Adsorbent in Peatland Rural Area Ngatijo, Ngatijo; Heriyanti, Heriyanti; Putri, Winda Arinda; Irunsah, Aslan; Ishartono, Bayu; Basuki, Rahmat
Jurnal Riset Kimia Vol 13, No 1 (2022): March
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v13i1.449

Abstract

The black water containing humic acid, HA in peat land rural area is a serious issue. This study aims to synthesis of activated carbon, AC from Ilalang Weeds, IW (Imperata cylindrica) as low-cost adsorbent for HA. The success AC synthesis by H3PO4 activator from IW was evidently characterized by Fourier Transform Infra-Red, FTIR and Scanning Electron Microscopy, SEM. The effects of pH solution, initial HA concentration, and contact time were systematically studied to investigate the performance of Activated Carbon from Ilalang Weeds, ACIW. The results showed the increasing of Langmuir monolayer capacity of HA adsorption on carbon from IW before (49.75 mg g-1) and after (56.82 mg g-1) activation process at the pH optimum 6.0. The equilibrium adsorption data fitted with the isotherm model was shifted from multilayer Freundlich model (CIW) into monolayer Langmuir model as the consequences of increasing pore diameter size and active sites intensity. Calculation of adsorption energy by Dubinin-Radushkevich (EDR) model, 0.50 and 2.24 kJ mol-1 for CIW and ACIW, respectively, showed the increasing of physical affinity of HA with the active sites of adsorbent. Adsorption kinetics showed that the adsorption behavior followed the Ho pseudo-second-order kinetic model. The experimental results of this work demonstrate that the ACIW can be used as a promising low-cost adsorbent for HA removal for clean water production in peat land rural area. 
Ekstrak Kafein sebagai Inhibitor Korosi Alami pada Logam Aluminium dalam Media Larutan Asam Sulfat dan Biosolar Marinda Sukmawanta, Shafara Najla; Wulan, Dyah Ratna; Widjajanti, Kristina; Azkiya, Noor Isnaini; Maryanty, Yanty
Jurnal Riset Kimia Vol 13, No 1 (2022): March
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v13i1.488

Abstract

This research, the caffeine extract of arabica coffee beans, cacao beans, and black tea leaves will be tested as a corrosion inhibitor on aluminium in an acidic environment and in biodiesel containing acid. This condition resembles the metabolism of microorganisms in biodiesel which produces H2SO4 as one of the causes of corrosion. Arabica coffee, cacao beans and black tea are natural organic ingredients containing caffeine which can inhibit corrosion. In the maceration process used a variable ratio of 70% ethanol solvent with organic matter, namely 225 grams of organic matter with 450 grams of ethanol and 150 grams of organic matter with 450 grams of ethanol. Concentration of caffeine extract from arabika coffee, cacao beans, and black tea leaves was obtained based on HPLC analysis at an effluent rate of 0.8 mL/min. The corrosion inhibition efficiency test on aluminium was observed at 0, 1, 4, 7 and 10 days of immersion. The previously used aluminium has been corroded with 12% H2SO4. The corrosion inhibition efficiency test on aluminium was observed at 0, 1, 4, 7 and 10 days of immersion. The best inhibitor results on aluminium soaked in biosolar containing 12% H2SO4 is tea 1.234,313 ppm with a corrosion rate of 1.6x10-4 g/cm2 day on day 1 to 2.5x10-4 g/ cm2 day on day 10 with an inhibition efficiency of 99%. While the aluminium soaked in H2SO4 12% is tea containing caffeine of 684.373 ppm with a corrosion rate of 1.3 x10-4 g/ cm2 day on day 1 to 3.3x10-4 g/ cm2 day on day 10 with an inhibition efficiency of 64%. The longer the immersion time of aluminium in H2SO4 media with the addition of organic inhibitors, the lower the corrosion rate value because the inhibitors form a layer that protects the aluminium.
Struktur, Sifat Dielektrik dan Optik Senyawa Aurivillius (Ca0,5Ba0,5)Bi4Ti4O15 yang Disintesis dengan Teknik Lelehan Garam Veronita, Silvi; Septiani, Upita; Zulhadjri, Zulhadjri
Jurnal Riset Kimia Vol 13, No 1 (2022): March
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v13i1.463

Abstract

Synthesis of ferroelectric material based onAurivillius phases, (Ca0.5Ba0.5)Bi4Ti4O15 (CBBT), have been done using a molten salts technique.The results of X-ray diffraction (XRD) analysis showed the characteristic peaks at 2θ = 12.93°, 17.31°, 21.64°, 23.23°, 27.71°, 30.33°, and 32.90° which was correspond to the four-layers of Aurivillius phase.Refinement structure using the Le Bail method, the sample is suitable for orthorhombic structures with the A21am space group. The orthorhombicity of the CBBT is small and nearer to tetragonal symmetry.Fourier Transform Infra-red (FTIR) spectra show distortion of TiO6 octahedral at 847 cm-1 and strain vibrations of TiO6 octahedra at 545 cm-1 due to A-O bonds.Analysis using Scanning Electron Microscopy (SEM) shows the morphology of the sample in the form of plate-like which is characteristic of Aurivillius phase.The ferroelectric to paraelectric phase transition temperature (Tc) was obtained at 635ºC.The band gap value of the CBBT compound was 3.17 eV, relatively the same with the CaBi4Ti4O15 (CBT) compound.

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