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Jaya Hardi
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Program Studi Kimia Fakultas MIPA, Uniiversitas Tadulako Jl. Soekarno-Hatta Km. 9, Tondo Palu, 94117
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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 12 Documents
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Search results for , issue "Vol. 8 No. 1 (2022): April Edition" : 12 Documents clear
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.
Pengaruh Metode Hidrolisis Terhadap Karakteristik Kimia Senyawa Kalsium Hasil Ekstraksi dari Cangkang Telur Ayam: The Effect of Hydrolysis Methods on Chemical Characteristics of Extracted Calcium Compounds from Chicken Eggshells Yurikke Julieta Permata Putri Sunarya; Yuni Kustiar; Nancy Siti Djenar; Ayu Ratna Permanasari
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.i1.15803

Abstract

Preparation of calcium compounds such as calcium hydroxide, calcium carbonate, and calcium oxide from chicken eggshells can be done through conventional methods that are cheaper and more practical, such as the sol-gel hydrolysis method and the coprecipitation method. In this study, the synthesis of calcium compounds from domestic chicken eggshells was carried out using two methods: the coprecipitation method and sol-gel method. Coprecipitation method consists of acid hydrolysis and alkaline hydrolysis. Sol-gel method consists of modification I and modification II. The AAS results showed that the calcium content from the hydrolysis of acids, alkaline, sol-gel modification I, and sol-gel modification II: 14.50%, 6.64%, 6.68%, and 9.93%, respectively. The FTIR showed that calcium compounds have four characteristic absorption bands, including O–H (3641.60 and 3448.72 cm-1) derived from Ca(OH)2 and H2O products, C=O (2981.95 - 1799 cm-1), and C–O (1448.54 – 874.68 cm-1) both of which from carbonate ions (CO3-) in CaCO3 both from eggshell and from the resulting calcium compounds, and Ca-O (711.73 cm-1) derived from CaO products. The results showed that the modification ll sol-gel method was the best because calcium compounds consisting of CaCO3, Ca(OH)2, and CaO were produced in a smooth texture, white color, and with the highest calcium content compared to other methods.
Analisis Kandungan Merkuri (Hg) pada Badan Air, Sedimen dan Biota yang Terdampak Aktivitas Pertambangan Emas di Kabupaten Parigi Moutong: Analysis of Mercury (Hg) Content in Water Bodies, Sediments, and Biota Affected by Gold Mining Activities in Parigi Moutong District Ernawaty Rasul; Musafira Musafira
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.i1.15835

Abstract

Parigi Moutong District is one of the regencies in Central Sulawesi province with the highest number of illegal mining activities. Unlicensed mining activities generally use mercury as an extracting agent and gold processing waste is generally disposed of in rivers or other water bodies. The purpose of this study was to analyze the levels of heavy metal mercury (Hg) in water bodies, sediments, and marine biota in gold mining areas in Parigi Moutong District. The sampling method was carried out by random sampling method, while the analysis of mercury content in samples of river water, sediment, and biota was carried out using atomic absorption spectroscopy (AAS). From the results of the study, it was found that mercury levels in water and sediment samples were still below the quality standard value which were 0.001 mg/Kg and 0.13 mg/Kg, respectively, while the mercury levels in all biota samples had exceeded the quality standard values ​(0.03 mg/Kg). This indicates that mercury has accumulated in the food chain in the water near the mine site.
Pembuatan Konsentrat Protein Ampas Tahu Menggunakan Garam Ammonium Sulfat: Manufacturing of Tofu Pulp Protein Concentrate Using Ammonium Sulphate Nurhaeni; Frischa Sari Kencana; Andi Tenri Ajeng; Khairuddin; Prismawiryanti; Syamsuddin; Dwi Juli Puspitasari; Indriani; Erwin Abdul Rahim
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.i1.15844

Abstract

Tofu pulp which generally becomes waste can be used as a source of protein concentrate. Protein concentrates from tofu pulp have been obtained at various ratios of tofu pulp: ammonium sulfate and ammonium sulfate salt concentration. The research was conducted to obtain the highest protein yield and content of tofu pulp protein concentrate. This study used a completely randomized design (CRD) with the independent variable being the ratio of tofu pulp filtrate: ammonium sulfate (1:2, 1:3, 1:4, 1:5, 1:6, and 1:7 (v/v)) and concentrations of ammonium sulfate (30, 40, 50, 60, 70, and 80%), while the dependent variables were the yield of protein concentrate and protein content. Production of protein concentrate used the salting-out method with ammonium sulfate salt. The ratio of tofu pulp: ammonium sulfate 70% obtained the best ratio of 1:5 with a yield of 41.6% and protein content of 84.58%. Tofu pulp as industrial waste can be a potential source of protein concentrate because it has a high protein content.
Viskositas dan Aktivitas Antibakteri Sabun Cair Berbasis VCO dengan Penambahan Ekstrak Etanol Daun Kelor (Moringa oleifera) Terhadap Bakteri Patogen: Viscosity and Antibacterial Activity of VCO-Based Liquid Soap with Addition of Ethanol Extract of Moringa Leaf (Moringa oleifera) Against Pathogenic Bacteria Pasjan Satrimafitrah; Mohamad Afdal; Jusman; Abd. Rahman Razak; Ahmad Ridhay; Nov Irmawati Inda
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.i1.15846

Abstract

This research was conducted by making VCO-based liquid soap with the addition of ethanol extract from Moringa leaves (Moringa oleifera). The purpose of this research was to determine the mass ratio of ethanol extracts of Moringa leaves and Virgin Coconut Oil (VCO) which produces soap with the highest antibacterial activity against tested bacteria. The other purpose is to determine the effect of the mass ratio against the viscosity of liquid soap. The research design used was a Completely Randomized Design (CRD) with the independent variables being the mass ratio of Moringa leaf ethanol extract and VCO which consists of five levels of 0:75 (F1), 1.5:73.5 (F2), 3:72(F3), and 4.5:70.5(F4) (w/w). The soap produced was tested for antibacterial activity againts Staphylococcus aureus, Escherichia coli, and Staphylococcus epidermidis using agar diffusion method as well as viscosity tests. The results showed that the antibacterial activity of liquid soap tends to be higher with increasing levels of ethanol extract of Moringa leaves. The liquid soap formula with the ratio of Moringa leaf ethanol extract: VCO of 3:72 (w/w) (Formula F3) had relatively higher antibacterial activity against the three tested bacteria. The inhibition zones against Staphylococcus aureus, Escherichia coli, and Staphylococcus epidermidis were 22.302 mm, 33.230 mm, and 36.490 mm, respectively, while the viscosity value of liquid soap was 47.433 cP.

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