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Indonesian Journal of Chemistry

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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 21 Documents

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Search results for , issue "Vol 5, No 2 (2005)" : 21 Documents clear

DETERMINATION of OPTIMUM CONDITION of PAPAIN ENZYME FROM PAPAYA VAR JAVA (Carica papaya) Aline Puspita Kusumadjaja; Rita Puspa Dewi
Indonesian Journal of Chemistry Vol 5, No 2 (2005)
Publisher : Universitas Gadjah Mada

A study to investigate the optimum condition of papain enzyme has been carried out. The condition that are investigated are pH and temperature, based on measurement of enzyme activity which is defined as mmole tyrosin that are released in reaction between papain enzyme and casein as substrat per minute. In this research, the papain enzyme was isolated from pepaya burung varietas Java. The enzyme was partially purified by precipitation method using 30% - 50% saturated acetone. The result showed that the optimum conditions of papain enzyme are in pH 6 with activity 2,606 U/mL, and temperature at 50 oC with activity 2,469 U/mL.

A STUDY OF THE SYNTHESIS OF HYBRID ORGANOSILICATE NANOTUBES Eko Sri Kunarti; Grainne M Moran
Indonesian Journal of Chemistry Vol 5, No 2 (2005)
Publisher : Universitas Gadjah Mada

Hybrid organosilicate nanotubes have been prepared by sol-gel chemistry, using crystalline ammonium tartrate as the tube-forming template. The nanotubes were prepared by controlled hydrolysis and co-condensation of tetraethyl orthosilicate (TEOS) and methyltriethoxysilane (MTES) at room temperature. The synthetic conditions have been systematically studied. The physical characteristics of the materials were examined by scanning electron microscopy (SEM) and the aging times of the tubes due to slow post-gelation condensation reactions was investigated. The morphology and microstructure of the nanotubes are greatly influenced by the synthetic conditions.

UTILIZATION OF Penaus monodon SHRIMP SHELL WASTE AS ADSORBENT OF CADMIUM(II) IN WATER MEDIUM Sari Edi Cahyaningrum; Amaria Amaria
Indonesian Journal of Chemistry Vol 5, No 2 (2005)
Publisher : Universitas Gadjah Mada

Utilization of shrimp shell has been optimum so that in this research preparation of adsorbent chitosan from shell of shrimp (Penaus monodon) as raw materials for cadmium(II) adsorption was carried out. The chitin was made by the deproteination, demineralization; chitosan was prepared by chitin deacetylation. This work was started with Infra Red Spectroscopic identification of functional group. Percentage of deacetylation was determined also by Infra Red Spectroscopy. Contant of nitrogen was determined by Kjeldhal method. The isotherm adsorption Langmuir model was employed for the determination of the energy and the capacity in adsorption. Result showed that chitosan could be isolated from shrimp shell waste with % deacetylation degree of 79.80 and % nitrogen 7.11. Cadmium(II) was chemically adsorbed on chitosan involving energi adsorption of 32.27 kJ/mole. Adsorption capacity of cadmium(II) was 6.35 x 10-5 mole/g. The constant adsorption rate k, was 0.91 x 10-3 s-1 and equilibrium adsorption desorption are K = 10.28 x 103. The ability adsorption of chitosan in real waste has the efficiency of 90%.

PARALLEL REACTION ON CATALYTIC HYDROGENATION REACTION OF CIS-ISOEUGENOL INTO 2-METHOXY-4-PROPYLPHENOL Muchalal Muchalal
Indonesian Journal of Chemistry Vol 5, No 2 (2005)
Publisher : Universitas Gadjah Mada

Catalytic hydrogenation of eugenol (Mr 164) and isoeugenol (Mr 164) by using synthetic catalyst Ni/-Al2O3 had been carried out. Eugenol transformation into 2-methoxy-4-propylphenol (Mr 166) as a main product could be achieved in 100% and no conversion reaction of eugenol into isoeugenol. If the raw material was 96% trans-isoeugenol or 61% cis-isoeugenol then the product was 67% or 92% of 2-methoxy-4-propylphenol. On the catalytic hydrogenation of trans-isoeugenol into 2-methoxy-4-propylphenol there was no parallel reaction of trans-isoeugenol into cis-isoeugenol. Conversely, catalytic reaction of cis-isoeugenol into 2-methoxy-4-propylphenol always followed by conversion reaction of cis-isoeugenol into trans-isoeugenol. Transformation of cis-isoeugenol into 2-methoxy-4-propylphenol below 200 oC was equilibrium reaction and above 200 oC was an irreversible reaction.

REACTION RESULT PREDICTION OF UO2 OXIDATION IN THERMOGRAVIMETRIC USE OF REGRESSION POLYNOMIAL Sahat Simbolon
Indonesian Journal of Chemistry Vol 5, No 2 (2005)
Publisher : Universitas Gadjah Mada

Thermogravimetric curve of UO2 oxidation reaction with oxygen from room temperature 25 oC to 425 oC had been depicted in three dimensions. The temperature oxidation reaction of UO2 sample was arranged 5 oC / minute and it was found that increasing of sample weight was 1.3 mg. Uranium dioxide (UO2) had not been reacted yet, reacted UO2, UO3 and U3O8 as the result of oxidation reaction were depicted in three dimensions. The nonlinear relationshps between temperature and time of oxidation reaction of UO2 were simulated in three dimensions using MATLAB Version 5.3 software version.

THE EFFECT OF DISTILLATE STORING DISTILLED FROM FRUCTOSE SYRUPS TOWARD ITS ACETALDEHYDE CONCENTRATION MEASURED BY GAS CHROMATOGRAPHY Maria Monica Sianita Basukiwardojo
Indonesian Journal of Chemistry Vol 5, No 2 (2005)
Publisher : Universitas Gadjah Mada

Acetaldehyde is a compound of aldehyde group that is very volatile and toxic. This compound can be found in fructose syrups used in carbonate beverages. The syrups had been distilled then analysed using gas chromatography. The concentration of acetaldehyde was 289.78 g/g in the distillates kept for one week, 295.30 g/g in those kept for two weeks, 429.45 g/g in those kept for three weeks, and 449.38 g/g in those kept for four weeks. The optimum column temperature was programmed with initial temperature of 40 oC held on for four minutes, then increasing by 40 oC/minute to 200 oC. It can be concluded that the longer the distillates have been kept, the greater the concentration of acetaldehyde in the distillates. A further research to investigate the present of microbe in the distillates and the effect of pH should be conducted.

THE EFFECTS OF BORON ADDITION AND PRESULFIDATION TEMPERATURE ON THE HDS ACTIVITY OF A Co-MoS2/Al2O3 CATALYST Usman Usman; Takeshi Kubota; Yasuaki Okamoto
Indonesian Journal of Chemistry Vol 5, No 2 (2005)
Publisher : Universitas Gadjah Mada

The effect of boron addition was studied on the hydrodesulfurization (HDS) of thiophene over Co-MoS2/B/Al2O3 (CVD-Co/MoS2/B/Al2O3), which was prepared by a CVD technique using Co(CO)3NO as a precursor of Co. The catalyst was characterized by means of NO adsorption, XPS, Raman Spectroscopy, FTIR, and TEM. The HDS activity of CVD-Co/MoS2/B/Al2O3 catalyst increased as the boron content increased up to about 0.6 and 1.2 wt% B for the catalyst presulfided at 673 and 773 K respectively, followed by a decrease with a further addition of boron loading. In spite of the activity increase, the amount of NO adsorption on MoS2/B/Al2O3 steadily decreased with increasing boron loading, suggesting that the dispersion of MoS2 particles is decreased by the addition of boron. Selective formation of the CoMoS phase on CVD-Co/MoS2/B/Al2O3 was achieved by the CVD technique. The TOF of the HDS over the CVD-Co/MoS2/B/Al2O3 catalyst, defined by the activity per Co atom forming the CoMoS phase, increased as high as 1.6 and 1.9 times for the catalyst presulfided at 673 and 773 K, respectively. It is concluded that the addition of boron weakens the interaction between Mo oxides and Al2O3 surface, promoting the formation of the so called Co-Mo-S ";;;pseudo";;; type II over CVD-Co/MoS2/B/Al2O3 presulfided at 673 K. The Co-Mo-S ";;;pseudo";;; type II is a metastable phase with the TOF value intermediate between Co-Mo-S type I and type II. With CVD-Co/MoS2/B/Al2O3 presulfided at 773 K, the addition of boron promotes the formation of ";;;real";;; Co-Mo-S type II, possibly by the formation of well-crystallized MoS2 structure.

THE CHARACTERISTIC CHANGES OF PROTEASE CG-10 IMMOBILIZED BY BENTONITE Rudiana Agustini
Indonesian Journal of Chemistry Vol 5, No 2 (2005)
Publisher : Universitas Gadjah Mada

The CG-10 isolate is a thermophile microorganism live in extreme environments, a hot spring located at Cangar East Java, having temperature 50 oC. The isolate had following characteristics: rod shaped cells, gram-positive, size of cells 6-14 µm, aerobic, and obligate thermophile. Based on the nucleotide sequences of its 16S-rRNA gene indicated that these isolate was closely related to Bacillus caldoxylolyticus (98.305% sequence similarity). The enzymes produced by thermophile microorganism were usually active at a higher temperature than that of the environment in which they live. Therefore it is possible to use this enzyme in industries requiring high temperature in their production processes. The CG-10 isolate grew well in a liquid waste of tofu and could secretion extracellular protease. The protease was isolated by fractioning at 35% (w/v) ammonium sulfate, centrifuged at 4000 rpm for 15 minutes, and had the following characteristics: optimum temperature 80 oC, optimum pH 8, the molecular weight 53.000-76.000 Dalton (for the protease showing the highest activity), pHI value between 7.5 up to 8.2, and could be classified as a serine alkaline protease. For increasing the efficiency of this protease in industries had been done by immobilization with bentonite. The immobilization process is done at optimum pH (pH 5). The characteristic changes research of protease CG-10 isolate immobilized by bentonite had been done. The immobile enzyme showed different characteristics for that of the native (mobile enzymes). The immobile enzyme showed a different optimum temperature, a higher heat resistance but the same optimum pH as the native enzyme.

OPTIMIZATION OF TIME REACTION AND HYDROXIDE ION CONCENTRATION ON FLAVONOID SYNTHESIS FROM BENZALDEHYDE AND ITS DERIVATIVES Sri Handayani; Sunarto, Sunarto,; Susila Kristianingrum
Indonesian Journal of Chemistry Vol 5, No 2 (2005)
Publisher : Universitas Gadjah Mada

The aim of this research is to determine the optimum time of reaction and concentration of hydroxide ion on chalcone, 4-methoxychalcone and 3,4-dimethoxychalcone synthesis. Chalcone and its derivatives were synthesized by dissolving KOH in ethanol followed by dropwise addition of acetophenone and benzaldehyde. Then, the mixture was stirred for several hours. Three benzaldehydes has been used, i.e : benzaldehyde, p-anysaldehyde and veratraldehyde. The time of reaction was varied for, 12, 18, 24, 30 and 36 hours. Furthermore, on the optimum reaction time for each benzaldehyde the hydroxyl ion concentration was varied from 5,7,9,11 and 13%(w/v). The results of this research suggested that the optimum time of chalchone synthesis was 12 hours, while, 4-methoxychalcone and 3,4-dimethoxychalcone were 30 hours. The optimum concentration of hydroxide ion of chalcone synthesis was 13% and for 4-methoxychalcone and 3,4-dimethoxychalcone were 11%.

Growth of the (001) face of borax crystals Suharso Suharso
Indonesian Journal of Chemistry Vol 5, No 2 (2005)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/ijc.21813

The growth rates of borax crystals from aqueous solutions in the (001) direction at various relative supersaturations were measured using in situ cell optical microscopy method. The result shows that the growth mechanism of the (001) face of borax crystal at temperature of 20 °C is spiral growth mechanism.

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