Garuda - Garba Rujukan Digital

Article Per Year (5 Year)

All

Indonesian Journal of Chemistry

ijc
Website

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).

Arjuna Subject : -

Articles 1,981 Documents

51 52 53 54 55

ADSORPTION OF GIBBERELLIC ACID (GA3) ONTO ACID ACTIVATED KAOLIN Sunardi Sunardi; Yateman Yateman Arryanto; Sutarno Sutarno
Indonesian Journal of Chemistry Vol 10, No 3 (2010)
Publisher : Universitas Gadjah Mada

Preparation, activation and adsorption study of natural kaolin from Tatakan, Tapin, South Kalimantan have been conducted. The activation of kaolin was done using 6 M HCl solutions at 90 °C for 3 h. The characterizations of kaolin were carried out by Fourier Transform Infrared, X-ray diffraction, and surface area analyzer. Adsorption parameters studied included the effect of pH, contact time, and concentration of gibberellic acid (GA3) onto kaolin samples. The amount of gibberellic acid adsorbed was determined using UV spectrophotometer. The adsorption capacity of kaolin was determined by Langmuir adsorption isotherm model. The result showed that activation of kaolin was resulted the larger specific surface area and more homogeneous composition of kaolin without any destruction of kaolin structure. Adsorption of gibberellic acid onto kaolin before and after activation showed that optimal adsorption was obtained at pH » 7 and reached the equilibrium within 4 h. The calculations result by Langmuir adsorption isotherm model showed that the increasing of adsorption capacity of acid activated kaolin is about 35%.

ADSORPTION OF Cr(VI) ON BLACK WATER Rasti Januarita; Herdiansyah Herdiansyah
Indonesian Journal of Chemistry Vol 3, No 3 (2003)
Publisher : Universitas Gadjah Mada

The effect of initial concentration of Cr(VI) on adsorption to black water of Gambut, District of Banjar, South Borneo has been investigated, as well as interaction between Cr(VI) species and functional black water organic fraction.The initial work was optimization of Cr(VI) determination using UV-Visible Spectrophotometry with diphenylcarbacide as complexing agent and preparation of black water using mixture of 2% HCl and 5% HF with HCl-HF ratio of 1 : 1 (v/v). The quantity of Cr(VI) species adsorbed on black water was calculated by determining the amount of Cr(VI) species in solution before and after interaction. The functional groups in interaction between Cr(VI) species and black water organic fraction was studied qualitatively using infrared spectroscopy.The results showed that optimum condition for Cr(VI) species analysis using UV-Visible spectrophotometry with diphenylcarbacide as complexing agent was at wave length of 540 nm, pH 1,5, 15 - 60 minutes at which complex remain stable, and minimum mol ratio of diphenylcarbacide : Cr(VI) 45 : 1, and has a sensitivity of 1.134 mg/L and detection limit of 0.00495 mg/L. The analysis was not affected by the presence of Cr(III) in concentration less than 40 times of Cr(VI) concentration. After treatment with HCl-HF the quantity of black water organic fraction showing humic acid properties decreased 0,1998 percent. Organic fraction of black water used adsorpted Cr(VI)with capacity of 4,050 mg/g.

ONE-STEP CONVERSION OF EUGENOL TO METHYL ISOEUGENOL USING MICROWAVE IRRADIATION IN SOLVENT-FREE CONDITIONS Marcellino Rudyanto; Lanny Hartanti
Indonesian Journal of Chemistry Vol 6, No 3 (2006)
Publisher : Universitas Gadjah Mada

A research on conversion of eugenol to methyl isoeugenol via one-step reaction with microwave irradiation has been carried out. Mixtures containing eugenol, sodium or potassium carbonate as solid support, with or without sodium or potassium hydroxide as base, with or without tetrabutylammonium bromide as phase transfer catalyst, with dimethyl sulfate as the methylating agent were irradiated in a domestic microwave oven for 20 - 50 seconds. It was revealed that one-step methylation and isomerization required combinations of sodium or potassium hydroxide base and tetrabutylammonium bromide. Without combination of base and TBAB only one product, i.e. methyl eugenol, was formed.

ORTHO-CHLOROANILINE DEGRADATION UNDER THE INFLUENCE OF OZONE IN AQUEOUS SOLUTION Ermin Katrin Winarno
Indonesian Journal of Chemistry Vol 7, No 2 (2007)
Publisher : Universitas Gadjah Mada

The degradation study on 2-chloroaniline (2-ClA) used as a model of water pollutant by ozonation was performed. The change of spectrum and substrate concentration of treated solutions were measured by spectrophotometer as well as by HPLC method. The change of solutions pH after ozonization was observed. The yields of the products formed (chloride ions, ammonium ions, and formaldehyde) were investigated as a function of ozonation time. The results showed that the ozonation gave to an efficient degradation of 2-ClA.

AB INITIO INVESTIGATION OF 12-CROWN-4 AND BENZO-12-CROWN-4 COMPLEXES WITH Li+, Na+, K+, Zn2+, Cd2+, AND Hg2+ Yahmin Yahmin; Harno Dwi Pranowo; Ria Armunanto
Indonesian Journal of Chemistry Vol 10, No 1 (2010)
Publisher : Universitas Gadjah Mada

The structure and binding energies of 12-crown-4 and benzo-12-crown-4 complexes with Li+, Na+, K+, Zn2+, Cd2+, and Hg2+were investigated with ab initio calculations using Hartree-Fock approximation and second-order perturbation theory. The basis set used in this study is lanl2mb. The structure optimization of cation-crown ether complexes was evaluated at HF/lanl2mb level of theory and interaction energy of the corresponding complexes was calculated at MP2/lanl2mb level of theory (MP2/lanl2mb//HF/lanl2mb). Interactions of the crown ethers and the cations were discussed in term of the structure parameter of crown ether. The binding energies of the complexes show that all complex formed from transition metal cations is more stable than the complexes formed from alkali metal cations.

MUTATION ON WD DIPEPTIDE MOTIFS OF THE p48 SUBUNIT OF CHROMATIN ASSEMBLY FACTOR-1 CAUSING VIABILITY AND GROWTH OF DT40 CHICKEN B CELL LINE Ahyar Ahmad; Harningsih Karim
Indonesian Journal of Chemistry Vol 10, No 2 (2010)
Publisher : Universitas Gadjah Mada

Chromatin assembly factor-1 (CAF-1), a protein complex consisting of three subunits, p150, p60, and p48, is highly conserved from yeast to humans and facilitated nucleosome assembly of newly replicated DNA. The p48 subunit, CAF-1p48 (p48), with seven WD (Trp-Asp) repeat motifs, is a member of the WD protein family. The immunoprecipitation experiment revealed that ß-propeller structure of p48 was less stringent for it's binding to HDAC-1, but more stringent for its binding to both histones H4 and CAF-1p60 but not to ASF-1, indicating that the proper ß-propeller structure of p48 is essential for the binding to these two proteins histone H4 and CAF-1p60. Complementation experiments, involving missense and truncated mutants of FLAG-tagged p48, revealed that mutations of every of seven WD dipeptide motifs, like both the N-terminal and C-terminal truncated mutations, could not rescue for the tet-induced lethality. These results indicate not only that p48 is essential for the viability of vertebrate cells, although the yeast p48 homolog is nonessential, but also that all the seven WD dipeptide motifs are necessary for the maintenance of the proper structure of p48 that is fundamentally important for cell viability.

REDUCTION AND OXIDATION PROCESSES OF CHROMIUM IN HUMIC ACID SUBFRACTION-SENSITIZED PHOTOCATALYST Uripto Trisno Santoso; Herdiansyah Herdiansyah; Sri Juari Santosa; Dwi Siswanta
Indonesian Journal of Chemistry Vol 4, No 3 (2004)
Publisher : Universitas Gadjah Mada

The process of reduction and oxidation of soluble chromium in humic acid subfraction-sensitized photocatalyst was studied. Humic acid was extracted from peat soil sampled in Gambut District, South Kalimantan. Humic acid (HA) was fractionated to humic acid subfraction (HAS) by centrifugation method. ZnO and TiO2 were applied as the photocatalysts produced by Merck, suspended in solution of 2 g/L. Two germicide UV lamps 30 watt (Philip®) was placed in a box at 20 cm above the samples. The results showed that HA or HAS sensitized the photoreduction of Cr(VI) by photocatalyst. The low molecular weight of HAS is more effective to act as sensitizer than the high molecular weight one. The yield of the photoreduction of Cr(VI) with photocatalysts enhanced both in the presence of Fe(II) ion and HAS. UV irradiation of the MnO4- solutions containing Cr(III) induced the photooxidation of Cr(III) to Cr(VI). The presence of Fe(III) or HAS doesn't inhibit significantly. The inhibition is enhanced by the present of both HAS and Fe(II) or HAS and Fe(III). This inhibition is enhanced more by the presence of ZnO or TiO2 photocalysts.

A NEW CLASS OF IONIC SOLVENTS, ELECTROLYTES AND ENGINEERING FLUIDS BASED ON 1,3-ALKYLMETHYL-1,2,3-BENZOTRIAZOLIUM SALTS Ahmad Mudzakir
Indonesian Journal of Chemistry Vol 6, No 2 (2006)
Publisher : Universitas Gadjah Mada

A new series of ionic liquids based on 1,3-alkylmethyl-1,2,3-benzotriazolium cation has been prepared. The spectroscopic, physical and electrochemical characteristics of this family of salts have been investigated with respect to potential usage as ionic solvents, electrolytes and engineering fluids. Incorporation of diverse anions including weak coordinating anion and pseudohalide with this benzotriazolium cation produces ionic liquids with advantageously low melting points and good thermal stability. Thermal analyses of these very stable salts included the determination of melting points (-65 to 164 oC) and decomposition temperatures (up to 291 oC). The electrochemical windows of representative benzotriazolium species has been investigated by cyclic voltammetry and determined to be ~ 3 V. The X-ray single crystal and spectroscopic studies revealed that weak hydrogen-bonding interactions between the benzotriazolium ring protons and the anions are present both in the solid state as well as in solution.

ENCAPSULATION OF HORSERADISH PEROXIDASE-GLUCOSE OXIDASE (HRP-GOx) IN SILICA AQUAGEL SYNTHESIZED FROM RICE HULL ASH FOR ENZYMATIC REACTION OF GLUCOSE Nuryono Nuryono; Narsito Narsito; Endang Astuti
Indonesian Journal of Chemistry Vol 8, No 2 (2008)
Publisher : Universitas Gadjah Mada

In recent years, the sol-gel technique has attracted increasing interest as a unique approach to immobilize biomolecules for bioanalytical applications as well as biochemical and biophysical studies. In this research, encapsulation of Horseradish peroxidase-Glucose oxidase (HRP-GOx) enzymes in silica aquagel from rice hull ash by sol-gel process has been carried out. In addition, the effect of several parameters (weight ratio of HRP to GOx, pH, temperature, sodium ion concentration) on enzyme activity was studied, as well. Rice hull ash, which was produced by ashing at 700 °C, was extracted it's silika by NaOH solution 1 M at 100 °C for two hours to produce sodium silikate (Na2SiO3) solution. The Na2SiO3 solution with pH of 13 was added with a strong cation exchanger resin, to produce sol solution with the pH of 4. Encapsulation was emphasized by mixing sol solution and phosphate buffer pH 7 containing HRP-GOx solution at volume ratio of buffer to sol solution 1:5. The mixture was transferred into 96-microwell plate and was aged for 24 hours. Enzymatic reaction was carried out by adding chromogenic solution of phenol and 4-aminoantipyrine (4-AAP) and b-D-glucose solution (as substrate) into the microwell. Enzymatic activity was examined by measuring absorbance of product solution at 490 nm with ELISA reader. Result of enzymatic activity for encapsulated enzymes (SGE) was compared to that for free enzymes (EB). Results showed that at the investigated condition, HRP-GOx enzymes gave high activity at weight ratio of HRP to GOx 10:1 and pH 7 for both SGE and EB. Encapsulation caused the enzymes activity decrease to 53.0±0.2 %. However, SGE was observed to be more stable on pH and temperature changes than EB. Study on the effect of sodium concentration showed that the increase of sodium concentration from 0.10 to 0.37 M decreased the enzymatic activity to 56±0.2%. Reusability test showed that the synthesized SGE was reusable with activity decrease of 60% within 23 days.

STUDY ON THE CONFORMATIONS OF p-(NITRO)METHOXYCALIX[4]ARENE AND p-(tert-BUTYL)METHOXYCALIX[4]ARENE USING HIGH LEVEL AB INITIO METHOD Hanggara Sudrajat; Danis Sriwijaya; Herman Siagian; Ria Armunanto
Indonesian Journal of Chemistry Vol 9, No 1 (2009)
Publisher : Universitas Gadjah Mada

Ab initio calculations have been performed in order to investigate the conformational characteristics of p-(nitro)methoxycalix[4]arene and p-(tert-butyl)methoxycalix[4]arene. The structures of four types (cone, partial cone, 1,2-alternate and 1,3-alternate) of conformers for each compound have been optimized by ab initio method at the restricted Møller-Plesset fourth-order perturbation (RMP4) level of theory using 6-311G and 6-311G++(d,p) basis sets. General trends in relative stabilities of p-(nitro)methoxycalix[4]arene and p-(tert-butyl)methoxycalix[4]arene are similar and decrease in following order: partial cone > cone > 1,3-alternate > 1,2-alternate. The calculated results of the most stable conformation of partial cone structure agree with the reported NMR experimental observations.

Page 53 of 199 | Total Record : 1981

51 52 53 54 55

Filter by Year

2001 2026

Filter By Issues

All Issue Vol 26, No 1 (2026) Vol 25, No 5 (2025) Vol 25, No 4 (2025) Vol 25, No 3 (2025) Vol 25, No 2 (2025) Vol 25, No 1 (2025) Vol 24, No 6 (2024) Vol 24, No 5 (2024) Vol 24, No 4 (2024) Vol 24, No 3 (2024) Vol 24, No 2 (2024) Vol 24, No 1 (2024) Vol 23, No 6 (2023) Vol 23, No 5 (2023) Vol 23, No 4 (2023) Vol 23, No 3 (2023) Vol 23, No 2 (2023) Vol 23, No 1 (2023) Vol 22, No 6 (2022) Vol 22, No 5 (2022) Vol 22, No 4 (2022) Vol 22, No 3 (2022) Vol 22, No 1 (2022) Vol 22, No 2 (2022) Vol 21, No 6 (2021) Vol 21, No 5 (2021) Vol 21, No 4 (2021) Vol 21, No 3 (2021) Vol 21, No 2 (2021) Vol 21, No 1 (2021) Vol 20, No 6 (2020) Vol 20, No 5 (2020) Vol 20, No 4 (2020) Vol 20, No 3 (2020) Vol 20, No 2 (2020) Vol 20, No 1 (2020) Vol 19, No 4 (2019) Vol 19, No 3 (2019) Vol 19, No 2 (2019) Vol 19, No 1 (2019) Vol 18, No 4 (2018) Vol 18, No 3 (2018) Vol 18, No 2 (2018) Vol 18, No 1 (2018) Vol 17, No 3 (2017) Vol 17, No 2 (2017) Vol 17, No 1 (2017) Vol 16, No 3 (2016) Vol 16, No 2 (2016) Vol 16, No 1 (2016) Vol 15, No 3 (2015) Vol 15, No 2 (2015) Vol 15, No 1 (2015) Vol 14, No 3 (2014) Vol 14, No 2 (2014) Vol 14, No 1 (2014) Vol 13, No 3 (2013) Vol 13, No 2 (2013) Vol 13, No 1 (2013) Vol 12, No 3 (2012) Vol 12, No 2 (2012) Vol 12, No 1 (2012) Vol 11, No 3 (2011) Vol 11, No 2 (2011) Vol 11, No 1 (2011) Vol 10, No 3 (2010) Vol 10, No 2 (2010) Vol 10, No 1 (2010) Vol 9, No 3 (2009) Vol 9, No 2 (2009) Vol 9, No 1 (2009) Vol 8, No 3 (2008) Vol 8, No 2 (2008) Vol 8, No 1 (2008) Vol 7, No 3 (2007) Vol 7, No 2 (2007) Vol 7, No 1 (2007) Vol 6, No 3 (2006) Vol 6, No 2 (2006) Vol 6, No 1 (2006) Vol 5, No 3 (2005) Vol 5, No 2 (2005) Vol 5, No 1 (2005) Vol 4, No 3 (2004) Vol 4, No 2 (2004) Vol 4, No 1 (2004) Vol 3, No 3 (2003) Vol 3, No 2 (2003) Vol 3, No 1 (2003) Vol 2, No 3 (2002) Vol 2, No 2 (2002) Vol 2, No 1 (2002) Vol 1, No 3 (2001) Vol 1, No 2 (2001) Vol 1, No 1 (2001) ARTICLE IN PRESS Article in press More Issue

Home Page

OAI Link

Editorial Team

Contact

Reviewer

Google Scholar

Contact Name
-

Contact Email
-

Phone
-

Journal Mail Official
-

Editorial Address
-

Location
Kab. sleman,

Daerah istimewa yogyakarta

INDONESIA

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Home Page

OAI Link

Editorial Team

Contact

Reviewer

Google Scholar

Contact Name -

Contact Email -

Phone -

Journal Mail Official -

Editorial Address -

Location Kab. sleman, Daerah istimewa yogyakarta INDONESIA

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Contact Name
-

Contact Email
-

Phone
-

Journal Mail Official
-

Editorial Address
-

Location
Kab. sleman,

Daerah istimewa yogyakarta

INDONESIA