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KOVALEN: Jurnal Riset Kimia
Published by Universitas Tadulako
ISSN : -     EISSN : 24775398     DOI : https://doi.org/10.22487/kovalen
Core Subject : Science, Engineering,
Chemical Engineering, Chemistry & Bioengineering Chemistry
KOVALEN: Jurnal Riset Kimia is a peer-reviewed journal of chemistry published by the Tadulako University, Indonesia. This journal concern with publishing the original research articles, review articles, and the current issues related to chemistry. Publishing frequency 3 issues per year, in April, August, and December.
Arjuna Subject : Kimia(semua kategori) - Kimia (Lain-Lain)
Articles 325 Documents
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SINTESIS ABSOLUT ASIMETRIK BARU Erwin Abdul Rahim
KOVALEN: Jurnal Riset Kimia Vol. 2 No. 1 (2016)
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

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Abstract

ABSTRACT New absolute asymmetric syntheses have been found.  Eugenol based-acetylenes monomers have been synthesized, corresponding three compounds and one unknown compound.  Two compounds are crystal chiral (1 and 2) and one (3) not.  Polymerization of chiral crystal and not were different although the structure is same.  After recrystalization polymerization of 1 and 2 compare with 3 also different.  This is one example of new absolute asymmetric synthesis. Keywords : New absolute asymmetric synthesis, eugenol, unknown compound, chiral crystal.
APLIKASI KULIT PISANG KEPOK (Musa paradisiaca formatypica) SEBAGAI ADSORBEN ION MERKURI (Hg) Musafira Musafira; A. Risman; Erwin Abdul Rahim
KOVALEN: Jurnal Riset Kimia Vol. 2 No. 1 (2016)
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

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Abstract

ABSTRACT The study aims are to determine the influence of the best of smooth and the best of volume eluent of the concentration of ion mercury (II) the colomn with the flow from top to bottom. These are used has a diameter 1 cm, height 35 cm and adsorbent 5 g. The variations upon the smooth which is used 10, 20 and 30 mL/minute ad the volume of eluent 10, 50, 100 and 150 mL with a concentration 60 mg/L at pH 5. This study is using random the factorial, each treatment done as much as two times. From the results showed that the best of smooth be achieved in the smooth 10 mL/minute and the best of volume eluent be achieved in the volume of 150 mL in adsorption of ion mercury (II). Keywords : Smooth, Volume of eluent, Kepok banana’s peels, Mercury.
AKTIVITAS ANTIOKSIDAN EKSTRAK UMBI SUWEG (Amorphophallus paeoniifolius) DARI BERBAGAI TINGKAT POLARITAS PELARUT Deddy Firman; Nurhaeni Nurhaeni; Ahmad Ridhay
KOVALEN: Jurnal Riset Kimia Vol. 2 No. 1 (2016)
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

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Abstract

ABSTRACT Has done research about antioxidant activity of suweg tuber (Amorphophallus campamulatus) based on the level of polar solvent. This research begins with in phased maceration extraction using n-hexane, ethyl acetate dan ethanol. Next step was antioxidant activity test with tyocyanate to n-hexane extract and DPPH methods to ethanol extract, ethyl acetate and vitamin C. The result showed antioxidant activity in n-hexane extract i.e. 14,96 %, end 77,13 % BHT while in ethyl acetate, ethanol and vitamin C reached IC50 value are 458,102 ppm, 223,268 ppm dan 26,76 ppm. Keywords: Suweg tuber, type of solvent, maceration, antioxidant
REDUKSI ION KALSIUM DALAM AIR TANAH MENGGUNAKAN ADSORBEN DARI KULIT PISANG KEPOK (Musa normalis L.) Rismawaty Sikanna
KOVALEN: Jurnal Riset Kimia Vol. 2 No. 1 (2016)
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

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Abstract

ABSTRACT It had been done a research with the aim to investigate the reduction of calcium ion in the soil water using adsorbents from Kepok banana (Musa Normalis L.) peel. This research used activated adsorbents with H2SO4 3 M and unactivated, with the various time of mixed until 10, 20, 30, 40, 50 and 60 minutes. The results showed that the reduction % of calcium ion of unactivated adsorbents were 2.65; 3.03; 3.79; 4.17; 4.54; 6.44; and activated were 15.15; 16.67; 19.32; 21.59; 22.73 and 23.48 respectively. Keywords: Reduction of calcium ion, soil water, Kepok banana peel.
Synthesis and Performance Evaluation of Cellulose-based Slow-release Fertilizer: A Review Dhyna Analyes Trirahayu; Ridwan P. Putra; Achmad Syarif Hidayat; Muhammad Iqbal Perdana; Erwina Safitri
KOVALEN: Jurnal Riset Kimia Vol. 8 No. 1 (2022): April Edition
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2022.v8.i1.15731

Abstract

Cellulose-based materials are attractive candidates for the fabrication of sustainable and eco-friendly slow-release fertilizers. The ability of the cellulose structure to be modified and functionalized makes it promising as a scaffold backbone in the development of advanced agricultural materials. In this review, different synthesis techniques of cellulose-based slow-release fertilizers are discussed. Crucial parameters in the design of the slow-release fertilizers (i.e., slow-release behavior, water retention properties, and biodegradability) are presented. The applications of cellulose-based fertilizers in enhancing the growth of agricultural and horticultural commodities are provided. To date, solution polymerization is more widely employed in the preparation of cellulose-based slow-release fertilizers due to its low cost and simple operation, with no solvent recovery required. Esterification tends to be the most typical reaction during the synthesis of the fertilizers because of its high substrate solubility and more straightforward product purification. This review can be used as a reference to develop other efficient cellulose-based slow-release fertilizers that can be utilized to delay the release of fertilizers and prevent the overuse of fertilizers.
Analisis Parameter Spesifik dan Nonspesifik Simplisia Daun Bawang Merah (Allium cepa L.): Analysis of Specific and Nonspecific Parameters of Shallot (Allium cepa L.) Leaves Simplicia Neneng Dwi Yana; Burhanudin Gummay; Mauritz Pandapotan Marpaung
KOVALEN: Jurnal Riset Kimia Vol. 8 No. 1 (2022): April Edition
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2022.v8.i1.15741

Abstract

Shallots are natural ingredients that are used as food enhancers for food and traditional medicines. This study aimed to analyze the specific and non-specific parameters of shallot (Allium cepa L.) Simplicia. Analysis of simplicia specific parameters in the form of material identity, organoleptic, macroscopic, and microscopic examination, levels of water-soluble extracts and ethanol soluble extracts while non-specifically in the form of a percentage of drying loss, water content, total ash, acid insoluble ash, and water-insoluble ash. The results of the research on specific parameters gave a yellowish-green simplicia color, a distinctive odor, in the form of powder, macroscopic examination of leeks elongated cylindrical, small round and hollow like a pipe, blunt leaf base, pointed leaf tip, green color, microscopic examination contained cover cells, gaps and epidermal cells, the levels for water-soluble extracts were 8.81±2.12%, the levels of ethanol-soluble compounds were 5.64±2.91%. The results of the study of non-specific parameters, the percentage of drying shrinkage was 0.89±0.57%, water content was 0.89±0.34%, total ash was 12.97±0.34%, acid-insoluble ash was 6.44±2.12%, and the water-insoluble ash content was 8.03±0.84%.
Sintesis Bioplastik Ramah Lingkungan Berbasis Pati Biji Durian dengan Filler Selulosa Sabut Kelapa: Synthesis of Environmentally Friendly Bioplastic Based on Durian Seed Starter with Coconut Cellulose Filler Ria Nurwidiyani; Ghufira; Nesbah; Deni Agus Triawan
KOVALEN: Jurnal Riset Kimia Vol. 8 No. 1 (2022): April Edition
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2022.v8.i1.15755

Abstract

Conventional plastic has become a concern because it is a problem for the environment. Bioplastics made from starch and natural polymers such as cellulose from coconut fiber can be a solution to these plastic problems. This study aims to synthesize and characterize bioplastics made from durian seed starch with sorbitol as a plasticizer and coconut coir cellulose as a filler. This research consisted of several stages of the procedure including the extraction of durian seed starch, isolation of coco coir cellulose, synthesis of bioplastics, and characterization of bioplastics. Bioplastics are made by the melt intercalation method. The resulting bioplastics were characterized by FTIR and mechanical tests (elastic modulus and tensile strength). In this study, the starch produced was characterized by a yellowish-white color and a rough texture with a yield of 10.95%. Before being used as a bioplastic filler, the coconut coir powder was bleached using H2O2 in a base condition to reduce the presence of lignin and hemicellulose. Based on the FTIR spectrum, the bleaching process was indicated by a decrease in the intensity of the absorption peak at wavenumbers of 1246 cm-1 and 1642 cm-1 which were characteristic absorptions for lignin and hemicellulose. The results of the mechanical test showed that the bioplastic composition with the highest tensile strength and modulus of elasticity was owned by bioplastic with 4% cellulose, namely 7.28 MPa and 0.73 MPa.
Verifikasi Metode Pengujian Kadar Nitrit dalam Air Limbah Secara Spektrofotometri UV-Visibel: Verification of a UV-Visible Spectrophotometry Method for Analysis of Nitrite Levels in Wastewater Imas Solihat; Ardina Purnama Tirta; Agung Pratama Ramdani; Achmad Nandang Roziafanto
KOVALEN: Jurnal Riset Kimia Vol. 8 No. 1 (2022): April Edition
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2022.v8.i1.15756

Abstract

Wastewater is the residue from a business and or activity in the form of liquid. One of the chemical compounds that cause pollution is nitrite. The nitrite level in wastewater is a key parameter in determining water quality because of its toxicity. The standard method for nitrite analysis refers to SNI 06-6989.9-2004 using sulfanilic acid and N-(1-naphthyl)-ethylenediamine dihydrochloride (NED) reagents. Linearity, instrument detection limit (LDI) and quantification detection limit (LOQ), precision, accuracy, and calculation of measurement uncertainty estimation are some of the verification parameters that were tested. The regression curve's results showed that the correlation value (r) = 0.9998, the instrument detection limit value of 0.0014 mg/L, the quantitation limit value of 0.0035 mg/L, the precision value (%SBR) of 1.30 percent, the accuracy value is in the range (90-100)% and the relative uncertainty of 5.88 %. The verification results suggested that the UV-Visible spectrophotometer-based nitrite test technique in wastewater had passed the acceptance requirements and may be utilized for routine laboratory analysis.
Aplikasi Antibakteri Nanopartikel Perak (NPAg) Hasil Biosintesis dengan Ekstrak Air Daun Kemangi: Application of Antibacterial from Silver Nanoparticles (AgNPs) Biosynthesis with Basil Leaf Extract Gusti Ayu Dewi Lestari; Pande Made Desy Ratnasari; James Sibarani
KOVALEN: Jurnal Riset Kimia Vol. 8 No. 1 (2022): April Edition
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2022.v8.i1.15771

Abstract

Nanotechnology is a technology that can be used to overcome several environmental problems. Synthesis of silver nanoparticles (AgNPs) mediated with basil leaf bioreductant with a concentration 0.5% at a temperature of 25⁰C has been carried out. The result of biosynthesis of AgNPs was analyzed using a UV-Vis spectrophotometer in which the SPR band showed the maximum wavelength of 429 nm. The size of AgNPs was determined by a Particle Size Analyzer (PSA), which its size was 86.83 nm. The morphology and elemental content of AgNPs were confirmed using SEM-EDS showing that the shape of AgNPs was irregularly spherical crystals while the EDS results showed a dominant peak at 3 keV indicating silver content. AgNPs showed strong antibacterial activity against Escherechia coli and moderate against Staphylococcus aureus.
Isolasi dan Pemurnian Protein dari Lembaga Jagung (Corn Germ) Menggunakan Metode Presipitasi dan Dialisis: Protein Isolation and Purification from Corn Germ Using Precipitation and Dialysis Methods Nancy Siti Djenar; Joko Suryadi
KOVALEN: Jurnal Riset Kimia Vol. 8 No. 1 (2022): April Edition
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2022.v8.i1.15790

Abstract

The protein contained in corn germ can be used as a raw material that has the potential to provide many benefits in the food, pharmaceutical, and plastic industries. Corn germ with the highest content of protein is around 12-18.4%. In this study, protein from corn germ was isolated and homogenized using tris buffer HCl at pH 7.2. To obtain the protein fraction, precipitation was carried out (salting-out) using a solution of (NH4)2SO4 with saturation levels of 25%, 50%, and 70% respectively. The purification process was carried out by dialysis for 24 hours. The dialysis produced pure protein with a concentration of 4.161%. Based on the identification of functional groups using an FT-IR spectrophotometer, it was shown that the isolated and purified corn germ protein contained four absorption bands, including amide A (3211.48 cm-1 and 3226.91 cm-1), amide I (1633 cm-1 and 1629.85 cm-1), amide II (1527 cm-1 and 1552.70 cm-1) and amide III (1296.16 cm-1). The four absorption bands correspond to the wavenumbers of corn protein stated in the literature and are estimated to contain albumin, globulin, glutelin, and zein.

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