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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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Karakterisasi Nanokomposit Poly(Lactic Acid)-Spent Bleaching Earth Regenerasi Termodifikasi: Characterization of Nanocomposite of Poly(Lactic Acid)-Modified Regenerated Spent Bleaching Earth Tika Paramitha; Johnner P. Sitompul
KOVALEN: Jurnal Riset Kimia Vol. 6 No. 2 (2020): Edisi Agustus
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2020.v6.i2.15207

Abstract

Development of renewable resource-based polymers attracts attention to solve environmental problems due to the build up of polymer (plastic). Poly(lactic acid) (PLA) is one of the most widely used polymers which have good biodegradability and processability. The addition of fillers to the PLA matrix aims to improve the characteristics of the PLA, such as mechanical properties of nanocomposites of PLA. Thus, PLA can be use as substitution of fossil fuel-based polymer. Spent Bleaching Earth (SBE) can be used as a filler after regeneration process. SBE was extracted and oxidized to take its oil content. Then, SBE was modified with urea solution to increase the interlayer distance. In this study, structure of nanocomposites was characterized using X-Ray Diffraction and mechanical properties of nanocomposites were characterized using Universal Testing Machines. X-Ray Diffraction characterization results show that PLA-SBE nanocomposite and PLA-modified regenerated SBE nanocomposites do not form new peaks, so SBE and modified regenerated SBE is intercalated and partially exfoliated in the PLA matrix. The degree of intercalation/exfoliation is indicated by the results of characterization of mechanical properties. The mechanical properties of PLA-SBE nanocomposite are lower than neat PLA, whereas the mechanical properties of PLA-modified regenerated SBE nanocomposites are higher than neat PLA. The best mechanical properties of nanocomposites were obtained for PLA-5% modified regenerated SBE, with elongation and tensile strength, 3.26%, and 42.22 MPa, respectively. Keywords: nanocomposites, poly(lactic acid), regeneration, spent bleaching earth
Uji Potensi Metabolit Sekunder Ekstrak Kulit Buah Petai (Parkia speciosa Hassk) terhadap Kadar Kreatinin dan Ureum Tikus Secara Spektrofotometri UV-Vis: Potential Test of Secondary Metabolites Extract of Petai Fruit Peel (Parkia speciosa Hassk) on Creatinine and Ureum Levels of Rats by UV-Vis Spectrophotometry Joni Tandi; Heru Khairul Muttaqin; Kiki Rizki Handayani; Sri Mulyani; Recky Patala
KOVALEN: Jurnal Riset Kimia Vol. 6 No. 2 (2020): Edisi Agustus
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2020.v6.i2.15225

Abstract

This study aims to determine the effectiveness of bitter beans peels (Parkia speciosa Hassk) extract on creatinine and urea levels, and the effective dose of the exctract on creatinine and urea levels. This research was a laboratory experiment using 25 rats which were divided into five treatment groups, each group consisting of 5 rats. Group 1 (normal control), group 2 (negative control) were given suspension of Na-CMC, groups 3, 4, and 5 respectively given petai rind ethanolic extract doses of 300, 400 and 500 mg/kg. The results showed that petai fruit (Parkia speciosa hassk) peels extract had an effect on creatinine and urea levels of diabetes hypercholesterolemia male rats by an effective dose of 300 mg/kg which has an effect on creatinine levels by an average of 0.38 mg/dL and ureum levels by an average of 12.9 mg/dL. Keywords: petai fruit peels extract, secondary metabolite, creatinine, ureum, Streptozotocin
Kinerja Elektroda Platina Terlapis Enzim Butirilkholinesterase-Selulosa Asetat-Glutaraldehida untuk Deteksi Diazinon: Performance of Platina Electrode Coated by Butyrylcholinesterase-Cellulose Acetate-Glutaraldehyde for Diazinon Detection Thamrin Azis; Nurhaeni; Caterina Bijang; A. Nurwahida
KOVALEN: Jurnal Riset Kimia Vol. 6 No. 2 (2020): Edisi Agustus
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2020.v6.i2.15237

Abstract

Diazinon (o, o-diethyl-o [2-isopropyl-6-methyl pyrimidynyl] phosphorotioate) is one of the organophosphate group pesticides widely used to protect cabbage plants (Brassica olarecea). Pesticide residues left in plants can bind to the cholinesterase enzyme and cause system disruption nerve. Analysis of diazinon residues in cabbage plants needs to be done to determine the level of toxicity caused. The electrochemical biosensor method as an electrochemical sensor uses a working electrode of platinum wire coated with the enzyme butybholchesteresterase (BChE) and cellulose acetate (SA) membrane and glutaraldehyde (GA) can be used for the analysis of pesticide residues. The test results of the SA electrode composition of the 10% GA 20% membrane obtained Nernst factor prices 28.1 µV / decade with a measurement range of 10-9 - 10-6 M, detection limit value of 1.29 x 10-7 M response time of 30 - 300 seconds. Keywords: biosensor, butylochholesterase, membrane, electrochemistry
Pengaruh Variasi Konsentrasi NaOH Terhadap Nilai Derajat Deasetilasi Kitosan dari Limbah Cangkang Kerang Hijau (Perna viridis L): The Effect of NaOH Concentration on The Value of The Deacetylation Degree of Chitosan from Green Mussels Shell Waste (Perna viridis L) Winda Trisna Wulandari; Nurzaman; Anindita Tri Kusuma Pratita; Keni Idacahyati
KOVALEN: Jurnal Riset Kimia Vol. 6 No. 3 (2020): Edisi Desember
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2020.v6.i3.15277

Abstract

Chitin which is the result of processing from green conch shell waste can be transformed into chitosan through a deacetylation process using variations in the concentration of NaOH. This study aims to determine the optimum conditions of variations in base concentration to the value of the degree of deacetylation of chitosan. The types of bases used are NaOH with the concentration variations of 50%, 55%, and 60%. Chitosan obtained was calculated the yield and characterized using FTIR. The results showed the optimum condition of the value of chitosan deacetylation degree was achieved by using 60% NaOH which produced the highest deacetylation degree value of 76.5%. Keywords: Green mussels shell, chitin, chitosan, deacetylation
Pengaruh Konsentrasi Surfaktan Non-Ionik Terhadap Viskositas Perekat Polivinil Asetat Berbasis Air: Effect of Non-Ionic Surfactant on Water-Based Adhesive Viscosity Rony Pasonang Sihombing; Robby Sudarman; Agustinus Ngatin
KOVALEN: Jurnal Riset Kimia Vol. 6 No. 3 (2020): Edisi Desember
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2020.v6.i3.15278

Abstract

Substrate combining could be done by using adhesive. In Indonesia, especially industrial field, solvent base adhesives were still being developed. This kind of adhesive was not environmental friendly and not safe handling. Therefore, Polyvinyl Acetate (PVAc) water-based adhesive was prepared as an outcome of this research as one of solution to overcome the problem above. Effect of surfactant concentration on the viscosity was aimed at this research. Semi continuous polymerization with stirring motor rates on 50 – 500 rpm was used (optional). Pressure of 1 atm, 750C temperature, 5 – 6 hours reaction time for each was used as polymerization operation in this research. Vinyl Acetate Monomer (VAM), partial hydrolysis Polyvinyl Alcohol (PVOH), water, Ammonium Persulfate (APS) were prepared as raw material. NP-10 and NP-06 were non-ionic surfactants which each concentration was varied in this research. Water-based adhesive with NP-06 concentration variation resulting in viscosity from 98 m.Pa for 0.17 %wt concentration to 213 m.Pa for 0.68 %wt concentration. While NP-10 concentration variation resulting viscosity from 143 m.Pa for 0.17 %wt to 321 m.Pa for 0.68 %wt concentration. Therefore, adhesive with NP-10 surfactant concentration variable has a higher viscosity rate than NP-06 ones. Keywords: Water-based adhesive, non-ionic surfactant, adhesive viscosity
Analisis Kadar Vitamin C Bawang Putih dan Hitam dengan Metode Spektrofotometri UV-Vis: Analysis of Vitamin C Levels of Garlic and Black Garlic by UV-Vis Spectrophotometric Method Magfira Jurwita; M. Nasir; Abdul Gani Haji
KOVALEN: Jurnal Riset Kimia Vol. 6 No. 3 (2020): Edisi Desember
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2020.v6.i3.15289

Abstract

An analysis of vitamin C levels of garlic and black garlic was done by UV-Vis spectrophotometric method. Garlic and black garlic contain a variety of nutrients and vitamins. Single and plural garlic is widely used as a medicine, besides garlic is currently also popular with garlic which is processed at temperatures between 60-80̊C with an environmental humidity of around 70-90% for 10-40 days. One of the vitamins contained in garlic includes vitamin C which acts as an antioxidant and is effective in dealing with free radicals. Vitamin C analysis was performed by the spectrophotometric method on the maximum wavelength is 250 nm with an absorbance value of 3.994. Results of analysis of vitamin C levels single garlic by 0.28% content of plural garlic by 0.27%. Vitamin C levels of single black garlic 0.29% (10 days), 0.31% (20 days), and 0.32% (30 days), plural black garlic Vitamin C levels 0.28% (10 days), 0.29% (20 days) and 0.31% (30 days).Based on ANOVA test results obtained there are differences in levels of vitamin C in single black garlic over several variations of time (days)and there are differences in levels of vitamin C in plural black garlic over several variations of time (days) because of Fcount ≥ Ftable.The coefficient of variation (KV) value is needed to test the level of accuracy of the analysis results. KV value in single garlic is 0.68% and plural garlic is 1.24%. KV value of single black garlic 0.3% (10 days), 0.25% (20 days), and 0.7% (30 days), KV of black garlic 0.55% (10 days), 0.61% (20 days), and 0.43% (30 days). Keywords: Single garlic, garlic plural, black garlic, fermentation, vitamin C levels
Konversi Karat Besi Menjadi Besi (III) Sulfat dan Pemanfaatannya Sebagai Adsorpsi Pewarna Tekstil: Iron Rust to Iron (III) Sulphate Conversion and the Utilization as Textile Dye Adsoption Ngatin Agustinus; Fatimah; Widya Fitria Nur Fauziah; Rony Pasonang Sihombing
KOVALEN: Jurnal Riset Kimia Vol. 6 No. 3 (2020): Edisi Desember
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2020.v6.i3.15308

Abstract

Iron rust was an iron oxide compound that was less attractive, dirty, brown in color, and could pollute the environment, causing water to turn brown. To minimize iron contamination, conversion was carried out into iron (III) sulfate which was useful as an adsorbent for textile dyes. The purpose of this study was to determine the effect of sulfuric acid concentration and volume of H2O2 10% used to convert iron rust into optimal iron (III) sulfate compounds. The method used was a laboratory experiment on a batch scale and the hydrate content in iron (III) sulfate was carried out by the gravimetric method and its ability as an adsorbent was carried out based on the adsorption of dyes using the spectrophotometric method. The results showed that a reactor filled with 3 grams of iron rust powder and 100 mL of sulfuric acid was stirred at 425 rpm at 80 0C for 30 minutes, added 15 ml 10% H2O2 followed by stirring and heating until the solution was saturated, cooled to form crystals. The crystalline yield in these conditions was the increase in sulfuric acid concentration which resulted in low process efficiency, namely 30.34% at 50% sulfuric acid concentration and 15 mL 10% H2O2. The addition of 10% H2O2 solution to 50 mL of 20% sulfuric acid solution and 3.0 grams of a carat as much as 5 mL-10 mL 10% H2O2 produced iron (III) sulfate with 26.53% process efficiency. Iron (III) sulfate is a white, light gray crystal with the chemical formula Fe2 (SO4)3.5 H2O which was a rhombic shaped crystal. and able to absorb the dye which showed that 1.0 g of iron (III) sulfate was able to absorb the highest amount of red dye in a volume of 100 mL of textile dye solution. Keywords: Iron rust, synthesis, iron (III), sulfuric acid, textile dyes
Identifikasi dan Purifikasi Vitelogenin Arwana Asia: Banjar, Pinoh (Scleropages macrocephalus), Papua (Scleropages jardinii) dan Super Red (Scleropages legendrei): Identification and Purification of Asian Arowana Vitellogenin: Banjar, Pinoh (Scleropages macrocephalus), Papua (Scleropages jardinii) and Super Red (Scleropages legendrei) Ahmad Musa; Remi Dugue; Rina Hirnawati; Bastiar Nur; Rendy Ginanjar; Sawung Cindelaras; Slamet Sugito
KOVALEN: Jurnal Riset Kimia Vol. 7 No. 1 (2021): Edisi April
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2021.v7.i1.15314

Abstract

Arowana fish (Scleropages sp.) are monomorphic species, those animals that physically could not be distinguished between male and female. The research was aimed to identify and purify Vitellogenin of four variants of Asian Arowana: Banjar, Papua, Pinoh, and Super red. 12 fishes, 3 from each variant were given estradiol stimulation through toad for vitellogenin production purpose. The SDS-PAGE results expressed that there were two types of Asian Arowana vitellogenin characters, single Vtg for Arowana Banjar, Pinoh (Scleropages macrocephalus) and Super Red (Scleropages legendrei) with a molecular weight of 180 kDa and double Vtg in Papuan Arowana (Scleropages jardinii) with molecular weight 180 and 110 kDa. Pure vitellogenin has been collected from 3 varieties, Banjar, Papua, and Super red with a concentration range between 0.1 - 0.67 mg / mL. The actual concentration is believed to be greater than the measured concentration.
Karakterisasi Simplisia dan Uji Aktivitas Antioksidan Ekstrak dan Fraksi Daun Pidada Merah (Sonneratia caseolaris L): Characterization and Evaluation of Antioxidant Activity of Red Pidada Leaves (Sonneratia caseolaris L) Eka Siswanto Syamsul; Supomo; Siti Jubaidah
KOVALEN: Jurnal Riset Kimia Vol. 6 No. 3 (2020): Edisi Desember
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2020.v6.i3.15319

Abstract

Research on red Pidada leaves (Sonneratia caseolaris L.) which is a mangrove plant with antioxidant potential has been carried out. This study aims to determine the simplicia characterization and activity of red Pidada leaf extracts and fractions as antioxidants. The results of the simplicia characterization were: water-soluble extract content of 11%, ethanol-soluble extract content of 16%, water content of 9%, ash content of 8.17%, and acid insoluble ash content of 0.48%. The antioxidant activity test was carried out using the DPPH (1,1-diphenyl-2-picrylhydrazyl) method. The antioxidant activity was determined by the IC50 (Inhibition Concentration) value. The results showed that the ethanol extract had an IC50 value of 24.22 ppm (very strong), n-hexane fraction 88.18 ppm (strong), ethyl acetate fraction 15.39 ppm (very strong), and ethanol fraction 38.41 ppm (very strong) Keywords: Sonneratia caseolaris L., antioxidants, DPPH, IC50
Uji Potensi Nefropati Diabetes Daun Sirih Merah (Piper croatum Ruiz & Pav) pada Tikus Putih Jantan (Rattus norvegicus): Potential Test of Diabetes Nefropative of Red Betel Leaf (Piper croatum Ruiz & Pav) on Male White Rats (Rattus norvegicus) Joni Tandi; Rizaldy Lalu; Magfirah; Yunlis Silintowe Kenta; Ronaldy Nobertson
KOVALEN: Jurnal Riset Kimia Vol. 6 No. 3 (2020): Edisi Desember
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2020.v6.i3.15323

Abstract

This study aims to determine the type of secondary metabolite compounds in red betel leaf ethanol extract, the potential of red betel leaf ethanol extract on blood glucose, creatinine, and urea levels of male white rats induced by streptozotocin. This study used 30 white male rats which were divided into 6 groups: normal control, negative control, positive control, the dose of 150, 250, and 350 mg/kg BW. The showed that results ethanol extract of red betel leaves contained alkaloids, flavonoids, phenols, saponins, and tannins. Ethanol extract of red betel leaf at a dose of 150 mg /kg BW is an effective dose in reducing levels glucose blood with an average value of decreased blood glucose levels of 238.25 mg/dL, and has an effect on creatinine and ureum, with an average dose of 350 mg/kg BW with a mean creatinine level of 0.64 mg/dL and mean ureum of 39.68 mg/dL. Keywords: Creatinine, ureum, red betel leaf, streptozotocin

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