Journal Jurnal Kimia Sains dan Aplikasi-
Jurnal Kimia Sains dan Aplikasi, Volume 22, pp 17-22; doi:10.14710/jksa.22.1.17-22
Abstract:This activity was to examine the ability of bentonite minerals from Yogyakarta to absorb the radiocesium contained in the solution. The purposes of the experiment were to determine sorption ability of bentonite mineral from Yogyakarta to absorb radiocesium in solution or groundwater and to enrich the Indonesia bentonite capability database to absorb radiocesium. The bentonite material was planned to be used as a buffer material of the engineered barrier system on the radwaste disposal facility in the future. The contact time, the presence of Na and K ions in the solution, as well as the variable of dissolved CsCl concentration were considered as experiment parameters. The value of Kd was also used as the indicator of radiocesium sorption into the bentonite samples. The experiment results shown that the maximum of Kd value was about 6800 mL/g for sample-1, and the presence of dissolved Na and K ions in the solution could reduce the values of Kd which were 800 and 300 mL/g for sample-1, respectively. Determination of isotherm sorption of radiocesium by bentonite from Yogyakarta was approximated by using linear equation or Freundlich law.
Jurnal Kimia Sains dan Aplikasi, Volume 22, pp 7-10; doi:10.14710/jksa.22.1.7-10
Abstract:Conversion of wood waste into bio-oil with low temperature pyrolysis method has been successfully carried out using tubular transport reactors. Pyrolysis carried out at temperatures of 250-300°C without using N2 gas. Bio-oil purified by a fractionation distillation method to remove water and light fraction compounds. The materials obtained from different types of wood waste, namely: Randu wood (Ceiba pentandra), Sengon wood (Paraserianthes falcataria), Coconut wood (Cocos nucifera), Bangkirei wood (Shorea laevis Ridl), Kruing wood (Dipterocarpus) and Meranti wood (Shorea leprosula). Bio-oil products are analyzed for their properties and characteristics, namely the nature of density, acidity, high heat value (HHV), and elements contained in bio-oil such as carbon, nitrogen and sulfur content based on SNI procedures, while bio-oil chemical compositions are investigated using Gas Chromatography Mass Spectroscopy (GC-MS). The maximum yield of bio-oil products occurs at 300°C by 40%. Bio-oil purification by fractional distillation method can produce purity of 16-31% wt. The characterization results of the chemical content of bio-oil showed that bio-oil of methyl formate, 2,6-dimetoxy phenol, 1,2,3 trimethoxy benzene, levoglucosan, 2,4-hexadienedioic acid and 1,2- benzenediol.
Jurnal Kimia Sains dan Aplikasi, Volume 22, pp 1-6; doi:10.14710/jksa.22.1.1-6
Abstract:Theoretical study of the use of cyano acid derivatives as electron acceptor groups in cyanidine as dye compounds of dye sensitized solar cells (DSSC) has been carried out based on energy parameters of HOMO-LUMO, LUMO electron localization, spectra, light absorption efficiency, coupling constants, and sensitizer bond length with TiO2. This study aims to determine the effect of cyanoacetic acid, cyanoacrylic benzothiadizole, cyanovinyl acid and cyanosynamic acid as electron acceptors on the photoelectric characteristics of cyanidine and determine the cyanoic acid derivative which can produce cyanidine photoelectric characteristics better based on energy parameters HOMO-LUMO, LUMO electron localization, spectra, light harvesting efficiency, coupling constant (VRP), and bond length of sensitizer with TiO2. This research begun with molecular optimization using DFT and TDDFT method with basis set of 6.311G *. HOMO-LUMO parameters used the same method with analysis technique using ECCE. The LUMO electron localization parameters use the same method, but the analysis technique used ECCE. Spectra using DFT method, using analytical technique using Chemcraft. Parameters of light absorption efficiency using DFT and TDDFT method with calculation technique using existing equations. Coupling constant parameters using the same method, the calculation technique used the energy equation of dye compounds were calculated in the conditions of HOMO, LUMO and TiO2 energy. Parameter length of the sensitizer bond with TiO2 were calculated used DFT method with avogadro analysis technique. Cyanidin cyanoacetate became the best modification based on HOMO LUMO energy parameter -4.569 and -1.01 eV, respesctively. In the electron localization parameter, the best modification was produced in cyanidine cyanoacetate with an electron-centered pattern on the cyanoacetic group. Spectra parameters produced the best modification, cyanoacetic cyanidine with a wavelength of 378.811 nm with osillator strength of 0.633. The light absorption efficiency parameters resulted in the best modification of cyanidin cyanoacetate with a value of 0.767. For parameter of clutch constant, best modification is cyanidin benzothiadizol sianoakrilik with a value -0.269. The best modification on the parameter length of the sensitizer bond with TiO2 was cyanidine cyanoacetate with a bond length of 1.926 Å.
Jurnal Kimia Sains dan Aplikasi, Volume 22, pp 11-16; doi:10.14710/jksa.22.1.11-16
Abstract:Synthesis of alginate-chitosan polyelectrolyte membrane and the determination of the physical-mechanical properties were carried out. Alginate-chitosan polyelectrolyte complex membrane can be made by mixing hydrosol alginate and chitosan hydrosol with a ratio of 1: 1 at pH 5.28. Membranes of alginate-chitosan polyelectrolyte complexes produced have physical-mechanical properties including load, elongation and elasticity, water absorption and resistance better than the constituent polymers. The results of FTIR spectroscopy analysis showed that there was an electrostatic interaction between alginate and chitosan through protonated amine groups of chitosan and carboxylic groups from alginate. Surface analyses by SEM showed that morphology of alginate-chitosan polyelectrolyte complex membrane was different with single membrane morphology
Jurnal Kimia Sains dan Aplikasi, Volume 22, pp 23-28; doi:10.14710/jksa.22.1.23-28
Abstract:Methylene blue removal by adsorption method had been done in batch method using adsorbent of used paper powder. Adsorption parameters covering adsorbent doses, contact times, pH, adsorbate concentrations and adsorption isotherm as well as desorption study of the absorbed methylene blue were evaluated. The results showed the highest adsorption of methylene blue was obtained at an optimum adsorbent dose, for 30 min at pH > 9. The maximum adsorption capacity of 30.77 mg/g was obtained with Langmuir isotherm model. While the effective methylene blue desorption on the used paper powder adsorbent was obtained c.a. 0.27 mg/g at pH 1.
Jurnal Kimia Sains dan Aplikasi, Volume 21, pp 237-241; doi:10.14710/jksa.21.4.237-241
Abstract:Java turmeric (Curcuma xanthoriza) is one of the native plants from Indonesia. Java turmeric is known as a medicinal plant with a high content of volatile oils. In this study, we investigated the chemical profile of java turmeric essential oil obtained by hydrodistillation associated with different harvesting times of the rhizome (7, 9, and 11 months). The constituent of the essential oil was determined by using gas chromatography-mass spectrometer. About 19, 20 and 34 compounds were identified in 7, 9, and 11-month old java turmeric. Fifteen compounds were found in all samples namely β-elemene, zingiberene, γ-elemene, β-farnesene, α-curcumene, benzofuran, α-cedrene, epicurzerenone, ar-curcumene, germacrone, aromadendrene, α–longipene, trans-caryophilene, curcuphenol, and xanthorrhizol. This study showed the level of all compound detected in 7, 9, and 11 months old of java turmeric is different.
Jurnal Kimia Sains dan Aplikasi, Volume 21, pp 161-165; doi:10.14710/jksa.21.4.161-165
Abstract:Validation of methods is necessary to ensure that the analytical methods used are appropriate and reliable. In this research, the determination of validation method and determination of inulin content from gembili bulb (Dioscorea esculenta L.). The method used for determining inulin levels is UV-Vis spectrophotometry. Based on the results obtained, the maximum wavelength determination of inulin levels is 520 nm. The method of analysis in this study meets the specified validation requirements. These parameters include the equation on the inulin raw curve y = 0.0045x +0.109 with the coefficient of determination 0.9992. The accuracy of the methods tested using the recovery test was 96.14-106.76% at concentrations of 25, 100, and 225 ppm. The intraday precision test is in the range of 2.67-6.82% at the same concentration as the accuracy test. Precision interday equal to 7.41% at concentration 225 ppm for 3 day analysis period. The values of LOD and LOQ are 3.58 ppm and 11.95 ppm, respectively. The concentration of inulin extract from gembili bulb is 840.44-12188.59 ppm.
Jurnal Kimia Sains dan Aplikasi, Volume 21, pp 198-204; doi:10.14710/jksa.21.4.198-204
Abstract:Melia azedarach L plant categorized as traditional medicinal plant is normally used as a medicine for cough, skin diseases, drug for malaria, diabetes, colon cancer, jaundice, vaginal discharge, fever and scabies. Melia azedarach leaves contain steroid, terpenoid, alkaloid, tannin, saponin, phenolic and flavonoid compounds. The purpose of this study was isolation of phenolic acid compounds and antioxidant activity test from Melia azedarach L. Leaves. The method used to isolate phenolic acid using 3 ways that were alkaline hydrolysis (HB), acid hydrolysis (HA), and without hydrolysis (TH). The separation of phenolic acid which has Rf not the same as standard phenolic acid was undertaken by preparative TLC and characterized using UV-Vis spectrophotometer, FT-IR, and LC-MS. Moreover, antioxidant test of phenolic acid using DPPH method was also conducted. The results showed that isolation of Melia azedarach L. Leaves resulted in HB, HA and TH fractions with the weight of 1.05 grams, 1.26 grams and 1.38 grams, respectively. The identification of phenolic acid which has Rf the same as standard phenolic acids was ferulic acid. While result of phenolic acid (FA) isolates which has Rf not the same as phenolic acids standard was caffeic acid after the identifying using UV-Vis spectrophotometer, FTIR and LC-MS. Qualitative antioxidant activity test showed that FA isolate had IC50 of 168,650 ppm. This result indicated that FA isolate is potential as antioxidant compound.
Jurnal Kimia Sains dan Aplikasi, Volume 21, pp 193-197; doi:10.14710/jksa.21.4.193-197
Abstract:Research on the synthesis of 4-hydroxy-2-methylchalcone from 4-hidroksi-2-metilbenzaldehida as formilated meta-cresol product and its antibacterial activity test has been conducted. As the first step, synthesis of 4-hydroxy-2-methylbenzaldehyde was carried out by treatment meta-cresol with chloroform through the Reimer-Tiemann formylation. Product is a brown solid with 23.94% yields. Furthermore, the 4-hydroxy-2-methylchalcone was synthesized using the 4-hydroxy-2-methylbenzaldehyde and acetophenone through the Claisen-Schmidt reaction. The product is a brownish yellow solid with 29.74% yields. Antibacterial test against Escherichia coli and Staphylococcus aureus bacteria was carried out by comparing the activity of 4-hydroxy-2-methylchalcone with 4-hydroxy-3-methoxychalcone, and chalcone compounds. The antibacterial activity test showed that the 4-hydroxy-2-methylchalcone compound, 4-hydroxy-3-methoxychalcone, and chalcone compounds gave a better antibacterial activity against Escherichia coli than the Staphylococcus aureus.
Jurnal Kimia Sains dan Aplikasi, Volume 21, pp 187-192; doi:10.14710/jksa.21.4.187-192
Abstract:The research had been conducted of the isolation of flavonoid compounds from water hyacinth plants (Eichhornia crassipes) and antioxidant activity test by DPPH (1,1-diphenyl-2-picrylhydrazyl) method. This research starts from maceration of water hyacinth with ethanol solvent. Ethanol extract was hydrolyzed with HCl. Flavonoid separation is carried out by column chromatography and preparative thin layer chromatography. The obtained isolates were analyzed by UV vis spectrophotometer and FTIR spectrophotometer. Antioxidant activity was carried out by DPPH method. Flavonoid isolates were obtained as heavy as 4.5 mg (0.006%). The results of the analysis of flavonoid isolates A4a with UV vis spectrophotometer appear at a wavelength of 368 nm (band I) and 260 nm (band II). The results of the analysis with FTIR shown that the isolates had functional groups O-H, aliphatic C-H, CH3, C =O, aromatic C = C, and C-O ether, it was suspected that flavonoid isolates had a basic structure of quercetin 7-methyl ether compounds. The results of antioxidant activity test of flavonoid isolates shown IC50 price of 254.66 mg / L