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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 320 Documents
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Biosintesis Nanopartikel ZnO dengan Ekstrak Temu Kunci (Boesenbergia rotunda) Dibantu Gelombang Mikro, Serta Pengujian Aktivitasnya Terhadap Bakteri : Biosynthesis of ZnO Nanoparticles Using Fingerroot (Boesenbergia rotunda) Extract Assisted by Microwave and Evaluation of Their Antibacterial Activity Junaedi, Yusup; Sugita, Purwantinigsih; Farid, Muhamad
KOVALEN: Jurnal Riset Kimia Vol. 10 No. 2 (2024): August 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.2024.v10.i2.17229

Abstract

Numerous ZnO nanoparticles have been successfully synthesized using diverse plant extracts, yet research utilizing B. rotunda extract as a capping agent with microwave assistance has been lacking. Hence, this study aimed to employ microwave-assisted B. rotunda extract to produce ZnO nanoparticles and test their antibacterial activity. By utilizing 10 mL of 1% (m/v) B. rotunda extract at pH 12.5 and calcinating for 3.8 hours at 200°C, coupled with 20 minutes of microwave treatment, ZnO nanoparticles averaging 78.78 nm in diameter were synthesized. Particle size was determined using the ImageJ software to analyze TEM images. UV-Vis absorption spectroscopy indicated a peak wavelength at 360 nm, while FTIR analysis identified compounds from B. rotunda extract crucial in nanoparticle formation. Antibacterial testing revealed the nanoparticles' ability to create an inhibition zone against E. coli growth.
Spesiasi dan Bioavailabilitas Merkuri dalam Sedimen Teluk Palu Pasca Gempa dan Tsunami dengan Metode Diffusive Gradient in Thin Film (DGT): Speciation and Bioavailability of Mercury in Palu Bay Sediments Post Earthquake and Tsunami Using the Diffusive Gradient in Thin Film (DGT) Method Sosidi, Husain; Khairuddin; Dwiyana, Putri; Ruslan, Ruslan
KOVALEN: Jurnal Riset Kimia Vol. 10 No. 2 (2024): August 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.2024.v10.i2.17264

Abstract

Speciation and bioavailability of mercury in the sediments of Palu Bay after the earthquake and tsunami were conducted using fractionation and Diffusion Gradient in Thin Films (DGT). This method has been conducted using sediment samples from the estuary of the Pondo River, Palu. Heavy metal speciation of mercury ions was conducted by looking at the distribution of mercury ions in various species by sequential extraction and heavy metal bioavailability of mercury ions. This method was conducted by looking at the migration of mercury ions from sediments into the seawaters using a Diffusive Gradient in Thin Films (DGT). The speciation of mercury ions concentration with sequential extraction as EFLE (easily, freely, leachable, exchangeable) fraction is about < 0.0005 ppm, the oxidizable fraction is about < 0.0005 ppm and the resistant fraction is between < 0.0005 ppm to 0.0063 ppm. The results of DGT experiments to study the migration of mercury ions from sediments into the seawaters during 3 days of immersion is between 0.01003 ppm and 0.01748 ppm. The availability of mercury ions concentration in the sediments allows for the migration of mercury ions into water.
Pengaruh Ukuran Partikel dan Suhu Terhadap Derajat Asetilasi dan Yield Pada Ekstraksi Kitin dari Belalang Melalui Green Method: The Effect of Particle Size and Temperature on the Degree of Acetylation and Yield in Chitin Extraction from Grasshoppers Using the Green Method Savitri, Meila; Pangestoe, Safina Handayani; Hilman Imadul Umam; Meka Saima Perdani; Teguh Pambudi
KOVALEN: Jurnal Riset Kimia Vol. 10 No. 2 (2024): August 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.2024.v10.i2.17268

Abstract

Grasshoppers are insects that are pests for agriculture. In recent years, humans have begun to realize the broader economic value of insects, which are not only used as animal feed but also as sustainable biopolymers, such as chitin and chitosan. Grasshoppers' body organs contain chitin, including the digestive tract (intestine), trachea system, and exoskeleton (outer skeleton). Currently, the chitin extraction process using the green method with Deep Eutectic Solvent (DES) is more popular because it reduces the use of dangerous chemicals, reduces waste, and is overall more environmentally friendly than using chemical and biological methods. In the chitin extraction process, process parameters, such as reaction time, temperature, and particle size of the raw material, are adjusted to obtain the desired properties of chitin. This research aims to determine the effect of particle size and temperature on chitin yield and degree of acetylation (DA). The research results show that the yield values ​​and DA values ​​produced in this research are not by similar references which have described the characteristics of chitin. However, there is one sample showing that the most optimal DA value is the BSC 7 150 mesh 90°C sample, at wavelengths of 1560 cm-1 and 2875 cm-1, producing a DA value of 55.79514% and DD 44.20485933%. The best yield value was BSC 2 110°C 50 mesh, with a value of 22.1%.
Adsorpsi Logam Cu(II) dengan Hidrogel CMC/Pektin Komposisi 2:1 Menggunakan Metode Freeze-Thaw: Adsorption of Cu(II) Metal by Hydrogel CMC/Pectin Composition of 2:1 Using The Freeze-Thaw Method Maelan, Nabila Maharani; Nurazizah Melani Dewi; Sri Andini; Meka Saima Perdani; Aulia Wahyuningtyas
KOVALEN: Jurnal Riset Kimia Vol. 10 No. 2 (2024): August 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.2024.v10.i2.17273

Abstract

The Citarum River is included in the category of the most polluted river in the world because it contains chemicals that can reduce air quality. This pollution not only affects air quality but also threatens public health and the surrounding ecosystem. Heavy metals, especially Cu(II), are one of the contaminants that have exceeded the threshold and can cause serious health impacts, including organ damage and nervous system disorders. Hydrogel is an alternative adsorbent that is widely used in various fields, especially in the field of air purification. Hydrogel has the ability to absorb and adsorb contaminants. In particular, Carboxymethyl Cellulose (CMC) hydrogel and pectin hydrogel have attracted much attention for safe water purification because they are non-toxic and have good biodegradability and biocompatibility. The researchers conducted a study on the adsorption of Cu(II) metal using a Carboxymethyl Cellulose (CMC) hydrogel adsorbent and pectin in a 2:1 composition through the Freeze-thaw method. FTIR analysis of the CMC/pectin hydrogel confirmed the presence of C-O-, O-H, C=O, C-H, OH bending, and COOH stretching vibrations. Based on BET analysis, the hydrogel has micropores, a type 1 isotherm, and a surface area of ​​1,889 m2/g. The Langmuir isotherm model was used to determine the ideal adsorption conditions to be a concentration of 298 ppm, an adsorption capacity of 1,0918 mg/g, and an adsorption efficiency of 13,485%.
Uji Aktivitas Antioksidan dan Kandungan Fitokimia Daun Benalu (Loranthus ferrugineus Roxb.) yang Tumbuh pada Ketinggian Tempat dan Inang Berbeda : Activity Antioxidant Test and Phytochemical Content of Mistletoe Leaves (Loranthus ferrugineus Roxb.) Growing at Different Altitudes and Host Types Iwit, Seswita; Ardi; Syarif, Auzar
KOVALEN: Jurnal Riset Kimia Vol. 10 No. 2 (2024): August 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.2024.v10.i2.17288

Abstract

Restrictions on synthetic antioxidants in several countries have caused the global community to switch to using natural antioxidants. One source of natural antioxidants is mistletoe leaves (Loranthus ferrugineus Roxb.).The presence of mistletoe in a place and host is an important aspect to pay attention to to get the best antioxidants. This research aims to determine the effect of different altitudes and host types on the antioxidant activity and phytochemical content of mistletoe leaves. This research was structured in a split-plot design with 2 factors, namely altitude (lowland and medium land) and host types (avocado, lime, cocoa, and dogfruit). Antioxidant activity test using the DPPH (2,2-diphenyl-1-picrylhydrazyl) method and phytochemical screening using reagents. Variables observed included extract yield percentage, antioxidant activity (IC50 value), and phytochemical screening. The results showed that altitude and host type significantly affected the antioxidant activity of mistletoe leaves. Mistletoe leaves in avocado hosts in the lowlands and medium land showed the best antioxidant activity, namely 155,94 µg/mL and 156,25 µg/mL in the weak antioxidant category, and the highest phytochemical content, namely flavonoids, alkaloids, tannins, saponins, and steroids.
Fitoremediasi Air Tercemar Nikel (Ni) dan Merkuri (Hg) Menggunakan Tanaman Azolla filiculoides Lam.: Phytoremediation of Nickel and Mercury Contaminated Water Using Azolla filiculoides Lam. Rudy, Sri Utami; Harso, Wahyu; Ramadanil; Iqbal, Moh.; Prismawiryanti
KOVALEN: Jurnal Riset Kimia Vol. 10 No. 2 (2024): August 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.2024.v10.i2.17343

Abstract

Water pollution from settlements, agriculture, and industry is a significant issue, as it introduces pollutants like heavy metals into water bodies, harming both humans and aquatic ecosystems. Phytoremediation is a cost-effective, eco-friendly technology for reducing heavy metals in water bodies. This study aimed to assess Azolla filiculoides plants' ability to absorb heavy metals nickel and mercury. The plants were grown in a hydroponic solution contaminated with 0.25 ppm of nickel and 0.5 ppm of mercury. The growth of the plants was measured based on their wet and dry weight, and the nickel and mercury content in the plant tissue was analyzed using Atomic Absorption Spectrophotometry (AAS). The study found that the growth of A. filiculoides plants was unaffected by the concentration of either nickel or mercury. The amount of nickel absorbed by the plants was 0 µg/g plant dry weight, while for mercury, it was 1654.82 µg/g. Based on the results, A. filiculoides plant is more promising for use as a phytoremediation agent for water bodies contaminated with mercury heavy metals rather than nickel heavy metals.
Induksi Aquilaria malaccensis Menggunakan Kombinasi Fusarium oxysporum dan Asam Salisilat: Aquilaria malaccensis Induction Using a Combination of Fusarium oxysporum and Salicylic Acid Rani, Diah Puspa; Jayuska, Afghani; Khotimah, Siti; Ardiningsih, Puji; Agus Wibowo, Muhammad
KOVALEN: Jurnal Riset Kimia Vol. 10 No. 3 (2024): December 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.2024.v10.i3.17041

Abstract

Agarwood is a resin from agarwood-producing plants that are given certain stimulants, thus stimulating the tree's defense system. The defense system produced is in the form of a sweet-smelling phytoalexin compound, better known as agarwood. Stimulants that can stimulate the formation of Gaharu are biological inoculants and chemical inducers. In this research, the biological inoculant used the Fusarium oxysporum fungus, and the chemical inducer used salicylic acid. This research aims to determine the effectiveness of using a combination of Fusarium oxysporum and salicylic acid in producing agarwood resin. The combination treatment of Fusarium oxysporum and salicylic acid was carried out using the injection method on Aquilaria malaccensis tree branches, and induction was carried out for 3 months. This research shows that the TLC test results in all treatments contain aloes, which is proven by the discovery of phenolic and terpenoid compounds. The combination treatment produces a color change intensity that is not darker and has a broader color change zone compared to the single treatment. Therefore, it can be concluded that the combination of Fusarium oxysporum and salicylic acid is less effective in producing Gaharu than the single treatment.
Pemanfaatan Limbah Tandan Kosong Kelapa Sawit dan Kulit Jagung Manis menjadi Kertas Karton menggunakan Metode Organosolv: Utilization of Empty Fruit Bunch and Sweet Corn Husk Waste into Paperboard using the Organosolv Method Ramayanti, Cindi; Sari, Winda Febrina; Mustain; Oktaviani, Erika Dwi; Mujiyanti, Apri
KOVALEN: Jurnal Riset Kimia Vol. 10 No. 3 (2024): December 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.2024.v10.i3.17358

Abstract

Paper is generally made using cellulose, which comes from wood, as raw material. However, if wood is used without stopping, it will cause global temperatures to rise and depletion of wood resources. One alternative to replacing wood in paper production is to use empty fruit bunch (EFB) waste and sweet corn husks. This research aims to obtain optimum conditions from variations in the ratio of raw materials and cooking process solutions and to obtain cardboard paper quality under SNI 0123:2008. The method used in this research is raw material preparation, and the pulp-making process uses the organosolv method. From the results of this research, the characteristics of pulp and paperboard obtained under optimum conditions at a raw material ratio of 30:70% w/w with a cooking solution ratio of 30:50:20% v/v have a cellulose content of 60% w/w, a tensile index of 5 .83 kN/m, absorption capacity 2.35 gr/m2, and grammage 428.67 gr/m2. From these data, it can be concluded that cardboard paper is produced from EFB raw materials and sweet corn husks with a raw material ratio of 30:70 %w/w and a cooking solution ratio of 30:50:20 %w/w using the process organosolv has met SNI 0123:2008 standards on tensile index, absorption capacity and grammage regarding the quality requirements for paperboard.
Pemanfaatan Limbah Puntung Rokok sebagai Inhibitor Korosi pada Baja St40 Menggunakan Metode Microwave Assisted Extraction (MAE) di Lingkungan NaCl 3,56%: Utilization of Cigarette Butts Waste as Corrosion Inhibitor on St40 Steel Using Microwave Assisted Extraction (MAE) Method in 3.56% NaCl Environment Alatif, Ikhsan Akmal; Permatasari, Rahma Puspa; Nurulgina, Rahma; Adzkia, Zahrotul Filza; Andayani, Puri; Putri, Sabrina Aisyah; Adinda; Trirahayu, Dhyna Analyes; Hadiningrum, Kunlestiowati
KOVALEN: Jurnal Riset Kimia Vol. 10 No. 3 (2024): December 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.2024.v10.i3.17394

Abstract

Corrosion is a problem that occurs in many industries and causes large losses. The use of corrosion inhibitors is one way to reduce or inhibit corrosion. Cigarette butt waste extract can be utilized as an organic corrosion inhibitor. This study aims to determine the yield of cigarette butt waste extract, the content of cigarette butt waste extract produced using the MAE method qualitatively, determine the optimum conditions for the extraction process with the MAE method based on variations in microwave power of 150 and 300 watts and calculate the efficiency of corrosion inhibitors and the effect of compounds contained in cigarette butt waste extract in 3.56% NaCl environment. The optimum MAE condition was 150 watts and 15 minutes, with an extract yield of 54.38%. Based on the GC-MS test, it is known that cigarette butts waste extract contains alkaloid, terpenoid, and phenol compounds as corrosion inhibitor compounds. Based on corrosion inhibitor testing, the addition of cigarette butt waste extract corrosion inhibitors can suppress or reduce the corrosion rate that occurs on metals with an inhibitor efficiency of 79.19% in non-aerated conditions and 71.53% in aeration with an inhibitor concentration of 1000 ppm in a 3.56% NaCl environment.
Aplikasi Edible Coating Albedo Semangka dengan Penambahan Ekstrak Etanol Daun Bandotan pada Tomat Napu: Application of Edible Coating of Watermelon Albedo with the Addition of Ethanol Extract of Bandotan Leaves on Napu Tomato Lutfi, Mohammad; Wulandari, Asri; Fito; Rahmadina, Hizra Nur; Chaedar, Nur; Nurhaeni; Amar, Aini Auliana
KOVALEN: Jurnal Riset Kimia Vol. 10 No. 3 (2024): December 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.2024.v10.i3.17408

Abstract

One of the causes of food waste is due to the lack of post-harvest handling of fruits or vegetables, therefore, an innovation is needed to overcome this problem, one of which is with edible coating. This study aimed to determine the characteristics of edible coatings from watermelon albedo pectin with the addition of Bandotan leaf extract as an antibacterial against Napu tomatoes. This study used a completely randomized design (CRD) consisting of 4 treatments, namely tomatoes (edible coating), tomatoes (edible coating + 12.5% bandotan leaf ethanol extract), tomatoes (edible coating + 25% bandotan leaf ethanol extract), and tomatoes (edible coating + 50% bandotan leaf ethanol extract). The watermelon albedo pectin characterization test results were the equivalent weight of 558.3 mg, methoxyl content of 6.1%, galacturonic acid content of 32.1%, moisture content of 11.469%, and ash content of 9.378%. From the results of tomato characterization tests for weight loss, moisture content, and microbial tests, the best treatment was produced by tomatoes (edible coating + 50% antibacterial), with consecutive results of 7.90%, 53.18%, 16.6 colonies (10-4 dilution), and 5.6 colonies (10-5 dilution).

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