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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 27 Documents

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Search results for , issue "Vol 8, No 2 (2008)" : 27 Documents clear

IMMOBILIZATION OF HUMIC ACID ON CHITOSAN USING PROTECTED CROSS-LINKING REACTION METHOD AND ITS APPLICATION AS SORBENT FOR Pb(II), Cd(II), AND Cr(III) Uripto Trisno Santoso; Dewi Umaningrum; Utami Irawati; Radna Nurmasari
Indonesian Journal of Chemistry Vol 8, No 2 (2008)
Publisher : Universitas Gadjah Mada

Immobilization of humic acid (HA) on chitosan has been done by using a protected cross-linking reaction method and the product was then utilized as sorbent for Pb(II), Cd(II), and Cr(III). HA was cross-linked with chitosan by using glutaraldehyde in order to obtain sorbent insoluble in aqueous acidic and basic solution. Protection of the active sites of HA was carried out by interacting HA with Pb(II) before performing the cross-lingking reaction in order to maintain its adsorption capacity The result showed that the amount of immobilized HA on chitosan was 99.7% by weight. The solubility of the immobilized HA were < 0.5% at pH 6 and < 1.0% at pH 12. The amount of immobilized HA and its solubility indicated that the protection pretreatment did not interfere the cross-linking reaction between HA and chitosan. The adsorption capacity of the sorbent for Pb(II), Cd(II), and Cr(III) were 416.7 mg/g, 332.3 mg/g, dan 714.3 mg/g, respectively.

RESVERATROL DIMERS FROM STEM BARK OF Hopea gregaria AND THEIR CYTOTOXIC PROPERTIES Sahidin Sahidin; Euis Holisotan Hakim; Yana Maolana Syah; Lia Dewi Juliawaty; Sjamsul Arifin Achmad; Laily Bin Din; Jalifah Latip
Indonesian Journal of Chemistry Vol 8, No 2 (2008)
Publisher : Universitas Gadjah Mada

Six resveratrol dimers have been isolated from the stem bark of H. gregaria, ampelopsin A (1), balanocarpol (2), ε-viniferin (3), hopeafuran (4), heimiol A (5), and parviflorol (6). The structures of these compounds were determined based on spectroscopic evidence such as UV, IR, 1-D, 2-D NMR and comparison with the reported data. These compound inventions are strengthen conclusion that Hopea tends to produce resveratrol dimers. Biological activity of those compounds against murine leukemia P-388 cells showed that ε-viniferin (3) is the most active compound with IC50 value 5.1 ± 0.3 μg/mL.

AFFINITY BIOSENSOR BASED ON SCREEN-PRINTED ELECTRODE MODIFIED WITH DNA FOR GENOTOXIC COMPOUNDS DETECTION Bambang Kuswandi
Indonesian Journal of Chemistry Vol 8, No 2 (2008)
Publisher : Universitas Gadjah Mada

An electrochemical method for the detection of the genotoxic compounds using a DNA-modified electrode was developed. This electrode was successfully used for the electrochemical detection of genotoxic compounds in water samples. The electrochemical results clearly demonstrated that, the development is related to the molecular interaction between the surface-linked DNA obtained from calf thymus and the target compounds, such as pollutants, in order to develop a simple device for rapid screening of genotoxic compounds in environmental samples. The detection of such compounds was measured by their effect on the oxidation signal of the guanine peak of the DNA immobilised on the surface of carbon based Screen-Printed Electrode (SPE) in disposable mode, and monitored by square-wave voltametric analysis. The DNA biosensor is able to detect known intercalating and groove-binding genotoxic compounds such as Dioxin, Bisphenol A, PCBs, and Phtalates. Application to real water samples is discussed and reported.

ELECTRON BEAM CURING OF EPOXY ACRYLATE COATINGS ON MEDIUM-DENSITY FIBERBOARD Sugiarto Danu; Darsono Darsono
Indonesian Journal of Chemistry Vol 8, No 2 (2008)
Publisher : Universitas Gadjah Mada

Most of the medium-density fiberboard (MDF) as an engineered woods need surface coating process before entering final products, such as furniture and building materials. The wood surface should be covered for surface protection from damage during service life as well as to enhance its appearance. Surface coating of MDF was conducted using epoxy acrylate resin either for clear and pigmented coatings. Titanium dioxide was used for white pigmented coatings. Coating was conducted at variation thickness level of 30 to 150 μm. Curing was carried out by using 350 kV electron beam accelerator at 1.35 mA current and 1.6 m/min conveyor speed to get the absorbed dose of 3 Mrad. Effect of coating thickness was evaluated by measuring the physical, mechanical and chemical properties of cured samples, i.e., hardness, gloss, transparency, adhesion, abrasion resistance, and chemical, solvent and stain resistance. Experimental results showed that pendulum hardness and abrasion resistance slightly increased whereas gloss, transparency and adhesion resistance decreased with increasing coating thickness, while chemical, solvent and stain resistance remains similar. In general, clear coating provides better properties than pigmented coating.

PRE-CONCENTRATION AND DETERMINATION OF HEAVY METALS ON MODIFIED ACTIVATED CARBON IN REAL SAMPLES F. Ahmadi; K. Niknam; A. Khanmohammadi; Z. Adibmehr
Indonesian Journal of Chemistry Vol 8, No 2 (2008)
Publisher : Universitas Gadjah Mada

A sensitive and simple method for the simultaneous pre-concentration of nutritionally important minerals in real samples has been reported. The method is based on the formation of metal complexes by N, N'-diacetyl-4-bromo-2, 6-di (aminomethyl) phenol (DBDP) loaded on activated carbon. The metals content on the complexes are then eluted using 6mL 4M HNO3, which are detected by AAS at resonance line. In this procedure, minerals such as Ni, Cu, Co, Pb Zn and Cd can be analyzed in one run by caring out the simultaneous separation and quantification of them. At optimum condition the response are linear over concentration range of for 0.03-1.1 µg mL-1 for Ni2+ , 0.03-1.0 µg mL-1 for Cu2+, 0.02-1.0 µg mL-1 for Pb2+ , 0.02-1.0 µg mL-1 for Co2+,0.02-1.1 µg mL-1 Zn2+ and 0.05-1.3 µg mL-1for Cd2+. The detection limits of each element are expressed as the amount of analytes in µg mL-1 giving a signal to noise ratio of 3 are equal to 2.5, 2.4, 1.6, 2.4, 1.9 and 2.1 for Ni2+ , Cu2+, Pb2+ , Co2+,Zn2+ and Cd2+. The ability of method for repeatable recovery of trace ion are 99.9, 98.7, 99.2 , 98.7, 98.5and 95.6 with R.S.D of 1.3, 1.4, 1.2, 1.4, 1.7 and 1.4 for Ni2+ , Cu2+, Pb2+ , Co2+,Zn2+ and Cd2+. The method has been successfully applied for these metals content evaluation in some real samples including natural water and vegetable.

THE EFFECT OF HYDROGEL DRESSING COPOLYMER POLI(VINYLPIRROLIDONE) (PVP) - k- CARRAGEENAN PREPARED BY RADIATION AND HEALING TIMES ON THE RADIUS REDUCTIONS BURN INJURIED OF WISTAR WHITE RAT Erizal Erizal
Indonesian Journal of Chemistry Vol 8, No 2 (2008)
Publisher : Universitas Gadjah Mada

The pre-clinical study of poly (vinyl pirrolidone) (PVP)-k- carrageenan hydrogel has been carried out. The aim of this study is to investigate the effect of hydrogel for healing burn injuried in the rats. The hydrogels were prepared by g-irradiation of aqueous solutions of 15 wt.-% PVP and 2 wt.-% k- carrageenan at a sterilization dose of 25 kGy. The physico-chemical properties of hydrogels were investigated. The results showed that the hydrogels suitable as candidate for wound dressing with gel fraction of 90 ± 5 (%), the water absorption was 4500 ± 55 (w/w), the water content was 83 ± 2 (%), tensile strength was 1,5 ± 0,1 kg/cm2 and adhesiveness was 0. The effect of the hydrogel as wound dressing was evaluated by attaching to a burn of the back skin of rats as a function of time observation. Advantages of the hydrogel were slightly faster rate of reducing radius diameter of injured burn skin, easy removal without damage to renewed skin.

ISOLATION AND CHARACTERIZATION OF CHITIN AND CHITOSAN PREPARED UNDER VARIOUS PROCESSING TIMES Crescentiana Dewi Poeloengasih; Hernawan Hernawan; M. Angwar
Indonesian Journal of Chemistry Vol 8, No 2 (2008)
Publisher : Universitas Gadjah Mada

Generally production of chitosan from crustacean shells consists of 4 steps, i.e. deproteinization, demineralization, decolorization and deacetylation. Simplification of chitosan production by elimination of deproteinization and/or demineralization, or reducing of reaction time would give many advantages, e.g. reduction of processing time and cost production due to reduction of chemical and power usage. The objectives of this research were to prepare chitosan under various processing times and to characterize the obtained chitin and chitosan. Chitin was prepared under various deproteinization times (0, 15, 30 min at 90 ºC using NaOH 2N) and demineralization times (0, 15, 30 min at ambient temperature using HCl 2N). Chitin was then bleached using aceton/etanol (1:1) for an hour. Deacetylation was achieved by treatment of chitin under condition at 120 ºC for 5 hr using NaOH 50%. Ash and nitrogen content, and degree of deacetylation of chitosan were evaluated. Demineralization and/or deproteinization times influenced the quality of chitin. Chitin and chitosan prepared without demineralization had white and chalky appearance, whereas the other chitosan were off-white in color. Ash and nitrogen contents of the chitosan products were 0.18 - 32.40% and 3.56 - 7.59%, respectively. Chitosan prepared under various processing times, except chitosan without demineralization treatment, had degree of deacetylation ≥ 70%.

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.

PHOTODEGRADATION AND ANTIOXIDANT ACTIVITY OF CHLOROPHYLL a FROM SPIRULINA (Spirulina sp.) POWDER Rebecca Christiana; Hari Kristopo; Leenawaty Limantara
Indonesian Journal of Chemistry Vol 8, No 2 (2008)
Publisher : Universitas Gadjah Mada

Research on chlorophyll a from Spirulina (Spirulina sp.) powder has been done in order to determine chlorophyll a content, to compare degradation pattern and kinetics degradation of chlorophyll a and crude extract as well as to investigate the difference of antioxidant activity of chlorophyll a with or without irradiation. Chlorophyll a content in spirulina powder was calculated by using Porra's equation. Irradiation and recovery ability of chlorophyll a were measured by using volpi light (Intralux 6100) equipped with daylight filter. The antioxidant activity of chlorophyll a was determined by using DPPH method. The results showed that chlorophyll a content was 2.886 μg/g dry weight. Chlorophyll a has the higher stability than crude extract against 60 minutes irradiation at room temperature. Kinetics degradation of chlorophyll a was based on second order while crude extract based on first order. Chlorophyll a and crude extract have recovery ability. The results also showed that antioxidant activity of chlorophyll a was increased after 60 minutes of irradiation.

SELF-CLEANING GLASS BASED ON ACID-TREATED TiO2 FILMS WITH PALMITIC ACID AS MODEL POLLUTANT Nurul Hidayat Aprilita; Indriana Kartini; Sofy Herawati Ratnaningtyas
Indonesian Journal of Chemistry Vol 8, No 2 (2008)
Publisher : Universitas Gadjah Mada

Preparation and characterization of self-cleaning glass based on acid-treated TiO2 films as well as evaluation on their self-cleaning properties have been carried out. Palmitic acid photodegradation was used as model pollutant. Acid-treated TiO2 powders were deposited on glass surface by using spraying technique. The XRD results showed that acid-treated TiO2 film exhibited decreased anatase crystalline size. The corresponding SEM images showed porous surface morphology. Layer densification was observed as the film thickness increased. TiO2 photocatalytic activity increased as the length of UV radiation increased. Best results were obtained at experimental condition of 35 hours UV radiation time. It is also observed that the thickness of TiO2 layers influenced the efficiency of palmitic acid photodegradation. The film with 1.661 µm thick TiO2 layers and 6.933 mg weight (0.7164 mg/cm2) could degrade 97.54 % mg palmitic acid/cm2 thin film.

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