KOVALEN: Jurnal Riset Kimia https://bestjournal.untad.ac.id/index.php/kovalen <p><strong>KOVALEN: Jurnal Riset Kimia</strong> is a peer-reviewed journal of chemistry that published by the Chemistry Department, 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. KOVALEN has been established since 2015 with volume 1 no 1 (December 2015) and has been <strong>accredited by DIKTI in the SINTA 4 category (No. 164/ E/ KPT/2021)</strong>.</p> <p><strong>ISSN:&nbsp;<strong><strong>2477-5398 (electronic)</strong></strong></strong></p> <p>The Scope of this journal including:<br>1. Theoretical and environmental chemistry study<br>2. Material and biomaterial synthesis, including their application&nbsp;<br>3. Isolation, purification, and modification of the natural product<br>4. Development and validation of analytical methods<br>5. Isolation and application of enzyme</p> en-US jr.hardi0803@gmail.com (Jaya Hardi) pasjan82@gmail.com (Pasjan Satrimafitrah) Thu, 31 Aug 2023 03:33:58 +0000 OJS http://blogs.law.harvard.edu/tech/rss 60 Laju Korosi Logam Baja Karbon Rendah di Larutan Garam pada Berbagai Konsentrasi Inhibitor Korosi dari Ekstrak Daun Pepaya https://bestjournal.untad.ac.id/index.php/kovalen/article/view/16344 <p>Papaya leaf extract could be used as an organic corrosion inhibitor. Corrosion inhibitors were used as a method to reduce corrosion rate. The most corrosive environment was the marine environment. The purpose of this study was to determine the best concentration of papaya (<em>Carica papaya</em>) leaf extract inhibitor which could reduce the corrosion rate of low carbon steel in a 3.56% NaCl solution environment. The maceration process was carried out for 24 hours with 70% ethanol solvent with a solute:solvent ratio of 1:8 (w/v) at room temperature. Inhibitor extracts were analyzed qualitatively with the phytochemical method. The addition of FeCl<sub>3</sub> was carried out on the inhibitor extract from papaya leaves. The color change occurred from blackish brown to greenish black which indicated the presence of tannin compounds in the papaya leaf extract. Corrosion testing was carried out with hot stream temperature setting at 45⁰C to 55⁰C and concentrations of inhibitor extracts at 300, 600, and 900 ppm. The test was conducted for 36 hours with a span of metal mass every 6 hours. Corrosion rate calculation is done by weight loss method. The results showed that papaya leaf extract inhibitors positive contained corrosion inhibitor and could reduce the corrosion rate in 3.56% NaCl solution. The corrosion rate without inhibitor is 1.023 mmpy. Corrosion rates with inhibitor concentrations of 300, 600, and 900 ppm were 0.755, 0.585, and 0.438 mmpy, respectively.</p> Ninik Lintang Edi Wahyuni, Rony Pasonang Sihombing, Nurcahyo, Agustinus Ngatin, Yunus Tonapa Sarungu, Alfiana Adhitasari, Bambang Soeswanto, Emma Hermawati Muhari, retno indarti Copyright (c) 2023 KOVALEN: Jurnal Riset Kimia https://bestjournal.untad.ac.id/index.php/kovalen/article/view/16344 Thu, 31 Aug 2023 02:29:38 +0000 Pengujian Antimikroba, Kelembaban, Tingkat Iritasi, dan Tinggi Busa pada Hand Soap Berbasis Minyak Jelantah dan Zaitun https://bestjournal.untad.ac.id/index.php/kovalen/article/view/16449 <p>Used cooking oil can disturb health if used continues, and the waste can damage of environment if discarded, therefore prevention is needed through processing (recycling) of used cooking oil to economic products, for example, hand soap. This research was the manufacture of hand soap using the waste of cooking oil, olive oil, and KOH as raw materials. The aim is to determine formulations of raw materials on good hand soap on organoleptic tests, pH, microbial inhibitory zones, humidity and irritation levels, and foam height. The formulations between used cooking oil and olive oil are F1 (125 g and 125 g), F2 (150 g and 100 g), F3 (175 g and 75 g), and F4 (200 g and 50 g). This study begins with the manufacture of hand soap using the experimental method, continued by testing the inhibiting zone of growth of <em>Propionibacterium acne</em> bacteria, moisture content, irritation level, foam height through descriptive tests with analytical observational, organoleptic, and pH. Results are all formulas of hand soap have strong effectiveness in inhibiting microbe growth, distinctive organoleptic, moisturizing, and anti-irritation. The foam height has met with SNI 06-4085-1996, however, the pH value has larger than the pH of SNI 06-4085-1966. The best hand soap preparation is Formula 1 (F1) because it has a pH value that is close to the pH value of SNI.</p> Syamsul Bakhri Mapparessa, Zakir Sabara, Andi Suryanto, Lisa, Tri Isra Wahyu Lestari Copyright (c) 2023 KOVALEN: Jurnal Riset Kimia https://bestjournal.untad.ac.id/index.php/kovalen/article/view/16449 Thu, 31 Aug 2023 02:39:04 +0000 Pengaruh Temperatur Kalsinasi Terhadap Kapasitas Ion Katalis Asam Heterogen Berbasis Silika dan Aplikasinya pada Sintesis Metil Oleat https://bestjournal.untad.ac.id/index.php/kovalen/article/view/16457 <p>Sulfated silica catalyst is a solid acid catalyst which in its application is used to accelerate esterification reactions. The purpose of this study was to determine the effect of calcination temperature and increasing the amount of catalyst on the effectiveness of silica as a catalyst in the formation of methyl oleate through esterification reactions. The synthesis of sulfuric acid catalyst from rice husk ash went through several stages, including preparation of raw material for rice husk ash, production of silica using the sol-gel method, manufacture of silica-based acid catalysts and characterization of the sulfated silica catalyst. The acid catalyst was prepared using impregnation method with sulfuric acid and calcined at various temperatures of 500, 600, 700 and 800<sup>o</sup>C. The characterization of the acid catalyst formed includes ionic capacity, catalyst performance in the esterification reaction, and the determination of the bond characteristic functional groups using FTIR. The results of ion capacity analysis showed that the highest acidity value was found in the sulfated silica catalyst calcined at 600<sup>o</sup>C of 0.372 mmol/gram. Testing the performance of the catalyst in the esterification reaction with a ratio of 4:1 (methanol:oleic acid) obtained an ester conversion of 38.89% using a catalyst of 30% of the amount of oleic acid. Identification results using FTIR show that sulfate ions have chemically interacted with silica at around 1103.28 cm<sup>-1</sup></p> Joko Suryadi, Nanda Nabila, Syafa Neiska Bayhaqi, Eko Andrijanto Copyright (c) 2023 KOVALEN: Jurnal Riset Kimia https://bestjournal.untad.ac.id/index.php/kovalen/article/view/16457 Thu, 31 Aug 2023 02:44:33 +0000 Penentuan Suhu Optimum Pirolisis Serbuk Gergaji Batang Kelapa https://bestjournal.untad.ac.id/index.php/kovalen/article/view/16482 <p>Research has been carried out on the utilization of biomass waste of coconut trunk sawdust using the pyrolysis method to produce two products simultaneously, namely charcoal and liquid smoke. In order to obtain charcoal products with optimum calorific value, it is necessary to understand the optimum pyrolysis conditions. One of the optimum conditions, namely pyrolysis temperature, was studied in this research. Pyrolysis was carried out in a simultaneous pyrolysis reactor at a flow rate of argon inert gas into the reactor of 2 liters/minute and a pyrolysis time of 2.5 hours with pyrolysis temperature variations of 350, 400, 450, and 500°C, respectively. The study showed that the optimum temperature of 400<sup>o</sup>C was obtained which gave a yield of 34% charcoal with a calorific value of 7229 kcal/kg. Compared to the calorific value of the raw material for coconut sawdust which is 4400 kcal/kg, there was an increase in the calorific value of the pyrolysis product by 64%. Based on the optimum temperature condition, liquid smoke as a by-product was also obtained with a yield of 45%. Charcoal can be used as a solid fuel or as a bioadsorbent in the treatment of liquid waste or clarification of liquid food products such as virgin coconut oil (VCO). Grade 3 liquid smoke can be used as a biopesticide, while grade 1 liquid smoke can be used as a food preservative. Given the benefits of the two pyrolysis products, both of the products from the current research have a promising&nbsp;market&nbsp;value.</p> Andi Aladin, Takdir Syarif, Andi Suryanto, Andi Magefira, Ardan Copyright (c) 2023 KOVALEN: Jurnal Riset Kimia https://bestjournal.untad.ac.id/index.php/kovalen/article/view/16482 Thu, 31 Aug 2023 02:50:54 +0000 Pengolahan Air Limbah Tahu Menggunakan Metode Elektrokoagulasi dan Adsorpsi Secara Kontinyu https://bestjournal.untad.ac.id/index.php/kovalen/article/view/16446 <p>Tofu wastewater contains a lot of protein therefore it is easily degraded to produce foul odors and harmful gases due to microbes. Protein levels can be reduced through the electrocoagulation method which is equipped with adsorption. The purpose of this study is to reduce the value of turbidity, TSS, and COD in tofu wastewater due to the influence of voltage in the electrocoagulation process which is equipped with an adsorption process. This research was conducted with an electrocoagulation process at a rate of 250L/min with voltage variations of 15, 20, and 24Volt in a 10L tank containing 3 pairs of aluminum (Al) electrodes connected with direct current. The output water from the electrocoagulation process flows into the settling basin and flows into the adsorption tank containing activated carbon adsorbent. Both of these continuous processes were the innovation of this research. Sampling was conducted every 10 minutes for analysis of turbidity, TSS, COD, and pH. The results of the output water analysis from the electrocoagulation process after passing through the precipitation and adsorption processes show that increasing the voltage results in the decrease of turbidity, TSS, and COD values, however, increased efficiency and pH. Thus, a voltage of 24V with a flow rate of 250mL/min resulted in the highest efficiency of the voltage variations (15, 20, and 24V) with a process time of 90 minutes with a turbidity impurity reduction efficiency value of 45.42% with a value of 41.36 NTU from 75.22NTU, TSS 91.42% with a decrease to 1827mg/L from 21288mg/L, and COD 55.56% with a COD value of 9600mg/L from 21600mg/L, and a process output water pH of 4.91, as well as a reduction in aluminum electrode weight of 1.024grams.</p> Ninik Lintang Edi Wahyuni, Nurcahyo, Unung Leoanggraini, Robby Sudarman, Bambang Soeswanto, Emma Hermawati Muhari, Agustinus Ngatin, Rony Pasonang Sihombing Copyright (c) 2023 KOVALEN: Jurnal Riset Kimia https://bestjournal.untad.ac.id/index.php/kovalen/article/view/16446 Thu, 31 Aug 2023 02:57:18 +0000 Penentuan Kadar Albumin Ikan Gabus (Channa striata) dengan Metode Biuret setelah Dikukus dan Dipepes https://bestjournal.untad.ac.id/index.php/kovalen/article/view/16391 <p>Snakehead fish (<em>Channa striata</em>) is a type of freshwater fish that contains high levels of protein albumin. The research was conducted to determine the albumin content in snakehead fish after the cooking process, both steamed and wrapped. The research was conducted using a completely randomized design with a factorial pattern, the first factor was the cooking method (steamed and wrapped) and the second was cooking time (10, 15, 20, and 20 minutes). Determination of protein albumin levels in snakehead fish after processing using the Biuret method. The steaming process for 15 minutes resulted in protein content in the snakehead fish of 0.76%, while the protein albumin that was lost was 19.28%. The wrapped method for 20 minutes has a remaining protein content of 0.59%, while the missing protein is 38.78%. The method of processing snakehead fish by steaming is better than the wrapping process.</p> Inda Hastuti N Naser, Syaiful Bahri, Pasjan Satrimafitrah, Abd. Rahman Razak, Ruslan, Ahmad Ridhay, Dwi Juli Puspitasari, Khairuddin Copyright (c) 2023 KOVALEN: Jurnal Riset Kimia https://bestjournal.untad.ac.id/index.php/kovalen/article/view/16391 Thu, 31 Aug 2023 02:59:45 +0000 Pemanfaatan Karbon Aktif Kulit Kacang Tanah untuk Menurunkan Kadar Ion logam Ca2+ dan Mg2+ dalam Air https://bestjournal.untad.ac.id/index.php/kovalen/article/view/16397 <p>Peanut shell has a high cellulose content as a carbon source which can be used as a basic ingredient for making activated charcoal. Research on peanut shells used as activated charcoal aims to determine the effect of contact time and pH on reducing levels of metal ions Ca<sup>2+</sup> and Mg<sup>2+</sup> in water. The research was conducted using contact time variables (30, 60, 90, 120, and 150 minutes) and pH (4, 5, 6, 7, and 8). Measurement of adsorbed metal levels was determined by using an Atomic Absorption Spectrophotometer (AAS). The research results obtained showed that variations in contact time could reduce Ca<sup>2+ </sup>levels by 77.46% -84.89% and Mg<sup>2+</sup> by 86.88%-88.91%. Adsorbents with variations in pH can reduce Ca<sup>2+ </sup>levels by 63.48%-88.74% and Mg<sup>2+</sup> by 90.35%-94.49%. The best conditions for the absorption of Ca<sup>2+</sup> and Mg<sup>2+</sup> ions were a contact time of 60 minutes and pH 4. The adsorbent was applied to reduce Ca<sup>2+</sup> and Mg<sup>2+</sup> levels in water with different hardness levels. The results of the analysis of water samples from two different locations had Ca<sup>2+</sup> levels of 94.180 mg/L and 210.20 mg/L, while Mg<sup>2+</sup> levels were 13.536 mg/L and 17.420 mg/L. The percentages of Ca<sup>2+</sup> adsorption for the two samples were 96.19% and 77.08%, and the percentages of Mg<sup>2+</sup> adsorption for the two samples were 21.16% and 10.63%. Carbon from peanut shells activated with sodium acetate has the potential to be used to reduce hardness in water.</p> Wilda Yanti, Husain Sosidi, Indriani, Prismawiryanti, Dwi Juli Puspitasari, Moh. Mirzan, Erwin Abdul Rahim, Nov Irmawati Inda Copyright (c) 2023 KOVALEN: Jurnal Riset Kimia https://bestjournal.untad.ac.id/index.php/kovalen/article/view/16397 Thu, 31 Aug 2023 03:02:18 +0000 Analisis Nutrisi Sereal dari Ampas Kelapa dan Ampas Susu Kedelai https://bestjournal.untad.ac.id/index.php/kovalen/article/view/16437 <p>Coconut pulp and soy milk pulp flour can be combined to reduce the use of wheat flour in the manufacture of cereals. The high fiber and protein content of coconut and soy milk pulp will improve the quality of cereals. The aim of this study was to obtain the mass ratio of coconut and soy milk pulp flour which produces cereals with high nutritional value. The ratio of coconut and soy milk pulp flour used was 0:100; 25:75; 50:50; 75:25; and 100:0 (w/w). Cereal quality was determined based on the value of carbohydrate, protein, fat, fiber, water, and ash content. The results showed that the protein, fat, water, and ash content met the SNI standard, while the fiber content was still higher than the maximum SNI limit. Statistically, the treatment of the ratio of coconut and soy milk pulp flour had a significant effect on all cereal quality parameters (sig. 0.00 &lt; α (0.05)). The high cereal protein content was found in all levels, namely in the range of 14.29-21.14%, while the fat content was in the range of 17.8-34.41%. The use of a 0:100 ratio produces carbohydrate content that meets SNI, which is more than 60%. The use of a combination of coconut pulp and soy milk pulp for the manufacture of cereals that needs to be developed is 25:75 (w/w), however still needs further modifications to reduce fiber content and increase the carbohydrate content.</p> Nurfita Sari, Ni Ketut Sumarni, Syaiful Bahri, Nurhaeni, Aini Auliana Amar, Syamsuddin, Jusman Copyright (c) 2023 KOVALEN: Jurnal Riset Kimia https://bestjournal.untad.ac.id/index.php/kovalen/article/view/16437 Thu, 31 Aug 2023 03:04:43 +0000 Pengaruh Ekstrak Biji Ketapang (Terminalia catappa L.) Terhadap Daya Hambat Pertumbuhan Bakteri Eschericia coli https://bestjournal.untad.ac.id/index.php/kovalen/article/view/16355 <p>Diarrheal is a disease that is widely endemic in tropical countries, especially in Indonesia. The bacterium that causes the appearance of diarrheal diseases is <em>Eschericia coli</em>. Plants that have the potential to be a cure for diarrhea are ketapang (<em>Terminalia catappa </em>L.). <em>Ketapang</em> seeds contain tannins, flavonoids, alkaloids, and saponins that can be used as antibacterial. This study aims to identify the effect of ketapang seed extract on the activity of <em>E. coli</em> bacteria. Extraction of ketapang seeds is carried out by the soxhlet extraction method with a solvent mixture of water and ethanol 96%. This research is a laboratory experiment. Bacterial growth inhibition test is carried out by the phytochemical test of ketapang seed extract with the addition of FeCl<sub>3</sub> solution showed positive results containing tannin compound indicated by the formation of a blackish-green colored solution. Positive control was carried out with amoxicillin and negative control with 70% ethanol solution. The results of the ANOVA test analysis obtained a significance value of 0.963, interpreted that there was a difference in inhibition power in variations in the concentration of <em>ketapang </em>seed extract with the most effective extract concentration being 0.8%. The higher the concentration of ketapang seed extract, the greater the inhibition against the growth of E. coli bacteria, therefore it can be used as a basic ingredient for anti-diarrhea drugs.</p> Zelen Surya Minata Minata, Annida Elfiana Citra Ardianty, Sumari, Yudhi Utomo Copyright (c) 2023 KOVALEN: Jurnal Riset Kimia https://bestjournal.untad.ac.id/index.php/kovalen/article/view/16355 Thu, 31 Aug 2023 03:11:12 +0000 Sintesis dan Uji Kinerja Membran Selulosa Termodifikasi Polistirena dari Ampas Tebu dengan Aditif Monosodium Glutamate untuk Menurunkan Nilai BOD dan COD Limbah Cair Tahu https://bestjournal.untad.ac.id/index.php/kovalen/article/view/16443 <p>Tofu liquid waste, which has high BOD and COD values, can contaminate waters if it is directly disposed of without prior treatment. Therefore, waste treatment is necessary before being released into water. One method for treating this waste is by using a cellulose acetate membrane. In this research, a cellulose acetate membrane was synthesized from sugarcane bagasse fibers using the phase inversion method. The membrane was added 6% MSG as an additive to improve its performance. The membrane was applied to treat tofu waste with BOD and COD parameters. The membrane’s flux values obtained in this study were 33.56 L/(m².hour) for water and 26.85 L/(m².hour) for tofu liquid waste. SEM test result showed that the membrane with a 6% MSG additive had more pores and a denser surface compared to the membrane without the additive. The membrane was capable of decreasing BOD and COD values by 62.5% and 75.3% respectively in liquid tofu waste.</p> Alvino Jefferson Sianipar, Suyata Copyright (c) 2023 KOVALEN: Jurnal Riset Kimia https://bestjournal.untad.ac.id/index.php/kovalen/article/view/16443 Thu, 31 Aug 2023 03:16:20 +0000 Formulasi Losion Ekstrak Kopi Robusta (Coffea canephora) sebagai Penangkal Radikal Bebas https://bestjournal.untad.ac.id/index.php/kovalen/article/view/16333 <p>Hand body lotion is a cosmetic used to moisturize skin in order to reduce dehydration. The coffee extract contains bioactive compounds that can provide high antioxidant activation. The purpose of this research is to study the effect of concentration on coffee extract and the addition of olive oil on organoleptic, hedonic, pH, and dispersive properties and to determine the value of the Sun Protection Factor (SPF) in the lotion. The research method involved extracting coffee grounds, heating the oil and water phases to 65°C, and mixing the two phases till it becomes an emulsion. Then add the oil and water to the mixture. The lotion that’s already in the container is ready for testing. This research used 8 formulas with coffee extract concentrations of 2% and 4%, and variations of olive oil from 0, 1, 2, and 3%. Organoleptic and hedonic tests were tried out on 25 respondents for 2 weeks. The pH test was carried out using a universal indicator. The spreadability test was carried out using a petri dish and the SPF test using a UV-visible spectrophotometer. The results showed that 25 respondents preferred formula 4 over the rest, which was white in color, thick in texture, soft scent and the aftertaste was moisturizing. All formulas have good spreading ability and all in the pH range of 5 – 8. The SPF test results were obtained for each formulation in the range of 6.78 – 12.95 and the highest SPF value was owned by F8 of 12.95.</p> Farid Mulana, Syaubari, Syarifah Nur Afifah, Indah Tri Lestari Copyright (c) 2023 KOVALEN: Jurnal Riset Kimia https://bestjournal.untad.ac.id/index.php/kovalen/article/view/16333 Thu, 31 Aug 2023 03:31:12 +0000