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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

99 100 101 102 103

UTILIZATION OF OIL PALM EMPTY FRUIT BUNCH (OPEFB) FOR BIOETHANOL PRODUCTION THROUGH ALKALI AND DILUTE ACID PRETREATMENT AND SIMULTANEOUS SACCHARIFICATION AND FERMENTATION Yanni Sudiyani; Euis Hermiati
Indonesian Journal of Chemistry Vol 10, No 2 (2010)
Publisher : Universitas Gadjah Mada

Lignocellulosic biomass is a potential alternative source of bioethanol for energy. The lignocellulosics are abundantly available in Indonesia. Most of them are wastes of agriculture, plantation and forestry. Among those wastes, oil palm empty fruit bunch (OP EFB) is one of a potential lignocellulosics to be converted to bioethanol. This EFB, which is wastes in oil palm factories, is quite abundant (around 25 million tons/year) and also has high content of cellulose (41-47%). The conversion of OPEFB to ethanol basically consists of three steps which are pretreatment, hydrolysis of cellulose and hemicellulose to simple sugars (hexoses and pentoses), and fermentation of simple sugars to ethanol. Acid and alkali pretreatments are considered the simplest methods and are potentially could be applied in the next couple of years. However, there are still some problems that have to be overcome to make the methods economically feasible. The high price of cellulose enzyme that is needed in the hydrolysis step is one of factors that cause the cost of EFB conversion is still high. Thus, the search of potential local microbes that could produce cellulase is crucial. Besides that, it is also important to explore fermenting microbes that could ferment six carbon sugars from cellulose as well as five carbon sugars from hemicellulose, so that the conversion of lignocellulosics, particularly EFB, would be more efficient.

SYNTHESIS OF MESOPOROUS TITANIA BY POTATO STARCH TEMPLATED SOL-GEL REACTIONS AND ITS CHARACTERIZATION Canggih Setya Budi; Indriana Kartini; Bambang Rusdiarso
Indonesian Journal of Chemistry Vol 10, No 1 (2010)
Publisher : Universitas Gadjah Mada

Mesoporous titania powders with high-order crystalline building blocks had been synthesized through the sol-gel process using potato starch gel template. Internal spongelike pore structure of starch gel template was generated by heating the starch granules at 95 °C in water solution and freezing the starch gel at -15 °C. The synthesis routes were performed by immersing the starch gel template for 4 days into the white colloidal solution of TiO2 nanoparticles, which were prepared by hydrolyzing titanium (IV) tetraisopropoxide (TTIP) in ethanol at pH 1. Mesoporous TiO2 powders were obtained by two different ways of template removal, performed by calcination of the TiO2-starch composites at 600 °C for 4 h or combination of extraction with ethanol-HCl (2:1) at 80 °C and calcination at 500 °C for 4 h. Fourier Transform Infra Red (FT-IR) spectra shows both of template removal methods result in decreasing of characteristic vibrational band of the starch hydrocarbon on the resulted TiO2 powders. The X-Ray Diffraction (XRD) pattern imply that the concentrations of starch gel template influence the anatase crystallite peaks intensity of the synthesized TiO2 powders. TiO2 templated by 20% of starch sponges gel has highest intensity of anatase crystallite. Scherrer calculation inidicated that anatase particle size has nanoscale dimmension up to 12.96 nm. The nano-architecture feature of mesoporous TiO2 scaffolds was also evaluated by the Scanning Electron Microscope (SEM). It is shown that mesoporous TiO2 framework consist of nanocrystalline TiO2 particles as buiding blocks. The N2 adsorption-desorption isotherm curves assign that TiO2 powder resulted from extraction-calcination route has higher mesoporosity than that of only calcinated. The synthesized mesoporous TiO2 powder exhibits high Brunauer-Emmet-Teller (BET) specific surface area up to 65.65 m2/g.

ALKYLARYLKETONE HOMOLOGOUS SERIES FOR DETERMINATION OF KOVATS RETENTION INDICES WITH RP-HPLC USING ACETONITRILE/WATER SYSTEM Rinaldi Idroes
Indonesian Journal of Chemistry Vol 10, No 1 (2010)
Publisher : Universitas Gadjah Mada

Some factors such as the changes of the stationary phase, temperature, pH-value, mobile-phase composition and flow rate play a crucial role in effecting the sensitivity of retention times in high performance liquid chromatography (HPLC) system. Utilizing a retention index system is one of the methods to minimize those effects. Besides the mentioned factors, dead-time influences on determining the retention index as well. In comparison with Gas Chromatography (GC), the retention Index determination method in HPLC is still widely discussed, due to the difficulty of utilizing n-alkane as standard. In addition, the solutes in HPLC interact with the mobile-phase, thus the retention behavior also depend on the mobile-phase. Actually, It is difficult to use n-alkanes in HPLC as standards in case of some considerable problems, due to they are very non polar but also large retention times which lack of chromophores. Therefore, using n-alkane in routine analysis could be inconvenient. In comparison with n-alkanes, the alkylarylketones homologous series are stable compounds, commercially available and easily detected by a UV detector. This paper introduces Determination of Kovats Retention Index in the HPLC using Alkylarylketone homologous series and then is connected with n-alkane as a frame of reference. Steroids were used as test substance for calculating Kovats retention index values in acetonitrile/water system.

IMMOBILIZATION OF HUMIC ACID ON CHITOSAN BEADS BY PROTECTED CROSS-LINKING METHOD AND ITS APPLICATION AS SORBENT FOR Pb(II) Radna Nurmasari; Uripto Trisno Santoso; Dewi Umaningrum; Taufiqur Rohman
Indonesian Journal of Chemistry Vol 10, No 1 (2010)
Publisher : Universitas Gadjah Mada

Immobilization of humic acid (HA) on chitosan beads has been done using a protected cross-linking reaction method and the product was then utilized as sorbent for Pb(II). Protection of the active sites of HA was carried out by interacting HA with Pb(II) before performing the cross-linking reaction in order to maintain its adsorption capacity. Protected-HA was cross-linked with chitosan beads using glutaraldehyde in order to obtain sorbent insoluble both in aqueous acidic and basic solution. The result showed that the amount of immobilized HA on beads chitosan was 88.60% by weight. The adsorption capacity of the protected-sorbent beads for Pb(II) was 784 mg/g. As a comparison, the adsorption capacity of the non-protected sorbent beads for Pb(II) was only 142 mg/g.

SYNTHESIZE AND CITOTOXICITY TEST OF SEVERAL COMPOUNDS OF MONO PARA-HIDROXY CHALCON Indyah Sulistyo Arty
Indonesian Journal of Chemistry Vol 10, No 1 (2010)
Publisher : Universitas Gadjah Mada

Five compounds of mono para-hidroxy chalcon were synthesized (TC1, TC2, TC3, TC4, and TC5) and tested their cytotoxicity against HeLa cell and Raji cell. The difference in substituent of TC1 (R4 =H), TC2 (R4 = OCH3), and TC3 (R4 = F), showed the difference of their citotoxicity against HeLa cell. The citotoxicity of TC1 (LC50 = 16.08 µg/mL) ≈ TC3 (LC50 = 13.37 µg/mL), but the substituent difference of TC2 (LC50 = 147.43 µg/mL), decreasing it citotoxicity 10 times. Like wise their citotoxicity against Raji cell of TC1 (LC50 = 36.44 µg/mL) ≈ TC3 (LC50 = 30.46 µg/mL), but the substituent difference of TC2 (LC50 = 468.94 µg/mL), decreasing it citotoxicity activity 15 times. Nevertheless the strength of citotoxicity TC4 (LC50 = 98.74 µg/mL) and TC5 (LC50 = 110.97 µg/mL) against Raji cell are stronger than the citotoxicity of two of them against HeLa cell (LC50 of TC4 = none, LC50 of TC5 = 576.53 µg/mL).

USFDA-GUIDELINE BASED VALIDATION OF TESTING METHOD FOR RIFAMPICIN IN INDONESIAN SERUM SPECIMEN Tri Joko Raharjo; Tri Wahyudi; Sismindari Sismindari
Indonesian Journal of Chemistry Vol 10, No 1 (2010)
Publisher : Universitas Gadjah Mada

Regarding a new regulation from Indonesia FDA (Badan POM-RI), all new non patent drugs should show bioequivalence with the originator drug prior to registration. Bioequivalence testing (BE-testing) has to be performed to the people that represented of population to which the drug to be administrated. BE testing need a valid bio-analytical method for certain drug target and group of population. This research report specific validation of bio-analysis of Rifampicin in Indonesian serum specimen in order to be used for BE testing. The extraction was performed using acetonitrile while the chromatographic separation was accomplished on a RP 18 column (250 × 4.6 mm i.d., 5 µm), with a mobile phase composed of KH2PO4 10 mM-Acetonitrile (40:60, v/v) and UV detection was set at 333 nm. The method shown specificity compared to blank serum specimen with retention time of rifampicin at 2.1 min. Lower limit of quantification (LLOQ) was 0.06 µg/mL with dynamic range up to 20 µg/mL (R>0.990). Precision of the method was very good with coefficient of variance (CV) 0.58; 7.40 and 5.56% for concentration at 0.06, 5, 15 µg/mL, respectively. Accuracies of the method were 3.22; 1.94; 1.90% for concentration 0.06, 5 and 15 µg/mL respectively. The average recoveries were 97.82, 95.50 and 97.31% for concentration of rifampicin 1, 5 and 5 µg/mL, respectively. The method was also shown reliable result on stability test on freezing-thawing, short-term and long-term stability as well as post preparation stability. Validation result shown that the method was ready to be used for Rifampicin BE testing with Indonesian subject.

SYNTHESIS AND CHARACTERIZATION OF HDPE PLASTIC FILM FOR HERBICIDE CONTAINER USING FLY ASH CLASS F AS FILLER Yatim Lailun Ni’mah; Lukman Atmaja; Hendro Juwono
Indonesian Journal of Chemistry Vol 9, No 3 (2009)
Publisher : Universitas Gadjah Mada

High Density Polyethylene (HDPE) plastic plays an important role in various applications, for example, it can be used as a container (bottle). Petrokimia Kayaku Company, a branch of Petrokimia Company of Gresik, produces herbicides using HDPE plastic bottles as their container. Those plastic bottles undergo degradation (kempot) for certain period of time. The aim of this research is to characterize and to synthesize the HDPE plastic film with class F fly ash as filler. The results expected from this research are producing the plastic with a better properties and durability. This research was initiated by taking the sample of HDPE plastic bottle and herbicides (containing Gramakuat, on active material parakuat dichloride) at Petrokimia Kayaku Company. Both the initial HDPE and the degraded bottles was analyzed their tensile strength and Fourier Transform-Infra Red (FTIR) spectral. The next step was to synthesize the HDPE plastic film using class F fly ash as filler and a coupling agent. The filler concentrations were 0%, 5%, 10%, 15%, and 20wt %. The best result was 5% filler concentration with tensile strength of 27.7 lbs. This HDPE film was then subjected to degradation test using pyridine solution with various concentrations (1%, 3% and 5%) for two weeks, thermal degradation at 100 °C for two weeks and chemical resistance by xylene with soak time variation of 24 h, 98 h and 168 h. The result of degradations test show that the value of tensile strength was decreased with the increase of filler consentration. The chemical resistance, however, was increased.

ADSORPTION OF GIBBERELLIC ACID ONTO NATURAL KAOLIN FROM TATAKAN, SOUTH KALIMANTAN Sunardi Sunardi; Yateman Arryanto; Sutarno Sutarno
Indonesian Journal of Chemistry Vol 9, No 3 (2009)
Publisher : Universitas Gadjah Mada

Adsorption of gibberellic acid (GA3) onto raw and purified kaolin from Tatakan, South Kalimantan was investigated in this study. Purification process was done by sedimentation to obtain relative pure kaolinite. Raw and purified kaolin samples were characterized by Fourier transformed infrared (FTIR) spectroscopy and X-ray diffractometer (XRD). The adsorption process was carried out in a batch system and the effect of pH, contact time and GA3 concentration were experimentally studied to evaluate the adsorption capacity. The amount of GA3 adsorbed was determined by UV spectrophotometer. The result showed that the raw kaolin from South Kalimantan consist of 53.36% kaolinite, 29.47% halloysite, 4.47% chlorite, 11.32% quartz and 1.38% christobalite and the purified kaolin consist of 73.03% kaolinite, 22.6% halloysite, 0.77% chlorite, 1.37% quartz and 2.23% christobalite Adsorption experimental indicate that the optimum adsorption took place at pH 7 and contact time for 4 h. Adsorption of GA3 was described by the Langmuir adsorption isotherm model with adsorption capacity of 8.91 mg/g on raw kaolin and 10.38 mg/g on purified kaolin.

THE PERFORMANCE OF CHITOSAN-FERRIHIDRYTE MEMBRANE FOR PHOSPHATE UPTAKE Barlah Rumhayati; Chasan Bisri; Wahyu O. Fajarina
Indonesian Journal of Chemistry Vol 9, No 3 (2009)
Publisher : Universitas Gadjah Mada

The uptake of orthophosphate onto the chitosan-ferrihydrite membrane has been studied. The membrane was proposed as a new binding layer of DGT technique. Membrane was prepared from a mixture of chitosan solution with ferrihydrite (FeOOH) paste and was crosslinked with glutaraldehyde. As a result, the uptake of orthophosphate was slow. The maximum adsorption capacity was reached at pH 5.0 and 8.0. It was mainly due to electrostatic attraction of phosphate ions to the protonated free amino groups of chitosan and to active sites of ferrihydrite. Desorption could be occurred optimally using 0.3 M of sulphuric acid. The absorption of SO42- ion to the protonated amino groups and the formation of ionic crosslinking could exchange and desorb phosphate ions. Ferrihydrite was eluted also by the acid. However, the eluted ferrihydrite readsorbed phosphate ions, resulted in minimizing the analysed free phosphate.

YOGYAKARTA AIR BORNE QUALITY BASED ON THE LEAD PARTICULATE CONCENTRATION Zaenal Abidin; Sunardi Sunardi
Indonesian Journal of Chemistry Vol 9, No 3 (2009)
Publisher : Universitas Gadjah Mada

Analysis of Yogyakarta air quality based on concentration of lead particulate using Fast Neutron Activation Analysis (FNAA) method has been done. The sample was taken 3 times in 16 strategic locations of Yogyakarta city using Hi-Vol air sampler that equipped with cellulose filter TFA 2133. The sample irradiated for 30 min with 14 MeV fast neutron and then counted using gamma spectroscopy (AccuSpec). The result indicated that concentration of Pb-208 along Diponegoro street up to Janti street respectively are minimally (0.689 - 0.775) mg/m3, and maximally: (1.598 - 1.785) mg/m3. According to DIY governor decree No. 153/2002 about the limited toxicity ambient on Yogyakarta area it is concentration that Pb. The concentration of Pb-208 are still below the permitted value of 2 mg/m3, but in certain areas, the Pb concentration is almost equal to upper limit of permitted concentration of Pb.

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