KOVALEN: Jurnal Riset Kimia

Sintesis dan Karakterisasi Fe₂TiO₅ dari Besi Oksida dan Titanium Dioksida dengan Metode Planetary Ball-Mill

Thu, 29 Dec 2022 13:05:18 +0000

The method of solid hydrogen storage through integration in metal hydride compounds is a new, promising method. This research has succeeded in synthesizing and characterizing the metal hydride alloy Fe-Ti system through a planetary ball-mill process. Based on the XRF analysis, it was found that the composition of Fe oxide content reached 56.22% while Ti oxide reached 43.78%. The FTIR study showed absorption at wavenumbers of 900 cm^-1 and 500 cm^-1. Both are typical absorptions for Ti-O and Fe-O groups, suggesting that the synthesized sample was successful. It can be seen from the XRD data that some of the diffractogram peaks of the resulting Fe-Ti compound match the peaks of the Fe₂TiO₅ and TiO₂ compounds obtained from the Powder Diffraction File (PDF) database number 00-003-0374. After the refinement was performed, information was obtained that the synthesis of Fe-Ti alloy material using the planetary ball mill technique produced Fe₂TiO₅.

Aktivitas Afrodisiak Ekstrak Etanol Daun Tumbuhan Bungkus (Smilax rotundifolia L.) terhadap Fertilitas Tikus Putih Jantan (Rattus norvegicus)

Ayu Wulandari, Recky Patala, Kiki Rizki Handayani, Monica Sandra Makatang — Thu, 29 Dec 2022 13:06:21 +0000

Aphrodisiac is a substance that can increase stamina, libido (sexual desire), and male fertility. This study aims to determine the secondary metabolites contained in the leaves of the Bungkus plant (Smilax rotundifolia L.), to determine the aphrodisiac activity of the leaf extract of the Bungkus plant on the fertility parameters of male white rats (Rattus norvegicus). This study used an experimental method with a modified post-test randomized controlled group design using 15 male white rats and 30 female white rats which were divided into 3 treatment groups, namely pairing each male rat with 2 female white rats (1 : 2). Each group consisted of 5 male rats and 10 female rats, namely the normal control group (NaCMC 0.5%), the positive control group (X-Gra 51.37 mg/kgBW), the control group the leaf extract test sample of the Bungkus plant (S. rotundifolia L.) with a dose of 200 mg/kgBW. The research data were analyzed using the SPSS 25 statistical test. The results of this study indicate that the leaf extract of the Bungkus plant contains secondary metabolites flavonoids, saponins, alkaloids and tannins. The administration of Bungkus leaf extract at a dose of 200 mg/kgBW showed a difference in the percentage value of the pregnancy index and a significant effect on the fertility index value.

Pengaruh dari Konsentrasi Elektrolit Tembaga Asetat-Asam Asetat dan Temperatur terhadap Efisiensi Arus pada Elektrodeposisi Baja Karbon Rendah dengan Tembaga

Widya Yeni Rawati, Warsono, Sri Widarti — Thu, 29 Dec 2022 13:07:18 +0000

One example of an electrolysis practicum module at the Chemistry Laboratory is the plating of copper on low-carbon steel metal with cyanide as the electrolyte. This cyanide electrolyte is commonly known as Zonax Copper. Due to the dangerous cyanide content, a replacement electrolyte that is safe, cheap, and easy to obtain for student practicum scales is sought. The purpose of this study was to determine the optimum temperature and composition of copper acetate-acetic acid as indicated by the largest current efficiency value. The composition of Cu-Acetate/Acetic Acid varied 0.2/0.4; 0.4/0.6; 0.6/1.2; 0.8/1.6, and 1/2 gram/250 mL. The coating process was carried out at temperatures of 30, 40, 45, 50, and 60^oC with an electrodeposition time of 10 minutes. The results show that the highest current efficiency was found in the composition (CH₃COO)₂Cu/CH₃COOH 1gram/ 2 ml, temperature 45℃ by 93%. The effect of temperature on current efficiency is in the form of a second-order polynomial with a correlation of research results >90%. The average maximum temperature is 42.68^oC and the largest current efficiency is 96% at a concentration of (CH₃COO)₂Cu/CH₃COOH 0.6 gr/1.2 ml. The current efficiency is directly proportional to the logarithmic concentration at temperatures of 30, 40, 45, and 50^oC.

Penambatan Molekuler Penghambatan Aktivitas Enzim α-Amilase dan α-Glukosidase oleh Senyawa Aktif Daun Kirinyuh (Chromolaena odorata L.)

Thu, 29 Dec 2022 13:12:45 +0000

An in silico study was conducted to inhibit the active compound in Kirinyuh leaves (Chromolaena odorata L.) against α-amylase and α-glucosidase enzymes using a molecular docking approach. The docking was carried out on 19 active compounds that had been identified in Kirinyuh leaves and were optimized using the PM3 method. The best results in inhibit on of the α-amylase enzyme were shown by compounds from the flavanone group, namely genkwanin and sakuranetin with binding affinities of -8.3 kcal/mol and -8.1 kcal/mol, respectively, while the best results in inhibiting on of the α-glucosidase enzyme were shown by two compounds from the hydroxybenzoic acid group, namely p-coumaric acid and p-hydroxybenzoic acid with bond affinities of -5.7 kcal.mol and -5.5 kcal.mol, respectively. The interaction between α-amylase with genkwanin and sakuranetin produces one conventional hydrogen bond GLU 233 and GLN 63 respectively. The interaction between α-glucosidase with p-coumaric acid and p-hydroxybenzoic acid produces three conventional hydrogen bonds, HIS 112; GLN 182; ASP 352 and GU 277; GLN 279; ASP 352.

Studi Pemanfaatan Limbah Cair Ikan dan Udang sebagai Substrat dalam Produksi Listrik pada Sistem Microbial Fuel Cell (MFC)

Alfiah Alif, Muhamad Jalil Baari, Amalyah Febryanti — Thu, 29 Dec 2022 13:13:45 +0000

Microbial fuel cell (MFC) is a technology that utilizes bacteria in organic medium that can convert chemical energy into electrical energy. This technology can be used to treat fishery waste and shrimp waste which is rich in organic matter. This study aimed to measure the performance of the MFC system on fishery wastewater and shrimp wastewater as a means of producing bio-electricity while reducing the waste load. This study used different types of electrodes, including zinc, aluminum, copper, and carbon graphite. This technology used 0.2 M KMNO4 electrolyte solution. The research method includes three stages; production of fishery wastewater and shrimp wastewater, assembly of a dual chamber MFC bioreactor, and measurement of waste electrical energy produced. The value of electricity production with the highest average in fishery wastewater was obtained by adding electrolyte solution to the Zn/Cu electrode during 117 hours of observation were 6.86 mA with a potential difference of 1.469 V meanwhile in shrimp wastewater was obtained by adding electrolyte solution to the Al/Cu electrode were 4.38 mA with a potential difference of 1.335 V.This study can be concluded that higher electricity production is obtained from the utilization of fish wastewater using Zn/Cu electrode.

Ekstraksi Teh Hijau dan Aplikasinya sebagai Pengendali Korosi Pada Pompa di Lingkungan Garam NaCl 3,56%

Retno Indarti — Thu, 29 Dec 2022 13:14:54 +0000

Green tea leaves contain antioxidant compounds that can be used as organic inhibitors in a corrosion process. Tea leaves were extracted by maceration method using 70% ethanol solution with a solid:solvent ratio of 1:8 (w/v) for 1 x 24 hours in an atmospheric room. The extract was then concentrated with a rotary evaporator and separated with solvent under vacuum conditions at 852 mbar, temperature of 70^oC and rotation of 80 rpm. The results of the qualitative test of extra tea leaves using 10% NaOH and 1% FeCl₃ changed the color to brownish orange and blue-black. This indicates the content of flavonoids and tannins. Green tea leaf extract is also applied to control the corrosion rate of brass metal. Variations in the concentration of tea leaves were 200, 400, 600 ppm in 3.56% NaCl solution. The pump circulation is carried out for 40 hours, the weight loss method is carried out every 8 hours. The average corrosion rate without inhibitor is 3.95 mmpy, the corrosion rate with 200 ppm inhibitor is 1.24 mmpy, the corrosion rate with 400 ppm inhibitor is 0.46 mmpy, the corrosion rate with 600 ppm inhibitor is 0.23 mmpy. A significant decrease in the corrosion rate occurred at a concentration of 600 ppm with an efficiency of 92.32%.

Efektivitas Fotodegradasi Lignin dari Limbah Ampas Sagu (Metroxylon sagu Rottb.) Menggunakan Katalis TiO₂

Thu, 29 Dec 2022 13:15:57 +0000

Lignin degradation from sago (Metroxylon sagu Rottb.) waste has been carried out using a TiO₂ catalyst. This research aims to determine the effectiveness of lignin degradation from sago waste using a TiO₂ catalyst. Lignin from sago pulp was isolated using 10% NaOH and characterized using Fourier Transform Infra Red (FTIR) spectroscopy. The results of the characterization using FTIR show that the absorption at wave number 2937.59 cm^-1 is the -C-H stretching vibration of the alkane functional groups, the absorption at wave number 2360.87 cm^-1 is the vibration of the C≡C triple bond, the wave numbers 1795.73 cm^-1 and 1637.56 cm^-1 are associated with the stretching of the carbonyl group. The absorption at wave number 1427.32 cm^-1 is a C-H vibration connected to an unsaturated bond in an aromatic ring. Absorptions at wave number 1105.21 cm^-1, 1128.36 cm^-1, 1153.43 cm^-1 were the stretching vibration of -C-H on the guaiasil ring, and the absorption at wave number 1022.27 cm^-1 was the stretching vibration of C-O-C ether. From this spectrum, it can be seen that lignin is not completely pure because it is probably still mixed with cellulose. The results of the effectiveness test of lignin degradation using a TiO₂ catalyst with the help of UV light were able to degrade the lignin isolated by 31.43%, for 3 hours at a lignin concentration of 40 ppm.

Adsorpsi Ion Pb(II) Menggunakan Silika Berbasis Pasir Alam Takari-NTT

Johnson N. Naat — Thu, 29 Dec 2022 13:16:58 +0000

This article reported the adsorption of Pb(II) ions using silica extracted from the natural sand of Takari, Timor island, Nusa Tenggara Timur province. The silica was extracted using hydrothermal and coprecipitation methods. The extracted silica was then used for Pb(II) adsorption under several optimization conditions: pH, contact time, concentration, kinetic model, and adsorption isotherm. The determination of Pb(II) concentration used dithizone reagent, forming complexes, and then measured using Uv-Vis. The pH, contact time, and optimum concentration results were 7, 60 minutes, and 80 mg/L, respectively, with an adsorption capacity (qe) of 0.679 mg/g, 0.745 mg/g, and 18.096 mg/g. The kinetic model followed a pseudo-order-2 with R² = 0.93, and the adsorption isotherm of Pb(II) metal ions followed the Temkin isotherm model. The results showed that the silica extracted from the natural sand of Takari of Timor island-Nusa Tenggara Timur could adsorb Pb(II) metal ions

Arang Aktif Ampas Tebu Termodifikasi Kitosan sebagai Adsorben Tetrasiklin: Pemanfaatan Metode Kolom

Thu, 29 Dec 2022 13:17:51 +0000

Currently, antibiotics are considered environmental pollutants because of their undesirable effects on human health and the environment, including the waste of antibiotics tetracycline hydrochloride. While on the other hand, bagasse is an agricultural waste that has no economic value. This study aims to study the characteristics of activated charcoal from bagasse and the use of bagasse as chitosan-modified activated charcoal using the column method to determine the variation of adsorbent height, flow rate, and acidity of the solution in the ability of the bagasse adsorbent to adsorb tetracycline hydrochloride. Bagasse goes through a carbonation process using a furnace at a temperature of 350°C until charcoal is formed. The next process is activation using 2 M phosphoric acids and compared based on SNI 06-3730-1995 regarding technically activated charcoal. Determination of functional groups using Fourier Transform Infra-Red, adsorbent morphology using Scanning Electron Microscope, and crystallinity using X-Ray Diffraction. The concentration of tetracycline hydrochloride before and after adsorption was measured using an Ultra Violet-Visible spectrophotometer. The best absorption results in the adsorption process were found at the adsorbent height of 14 cm (99%), the flow rate of 0.5mL/minute (92%), and pH 4 (93%).

Pengaruh Konsentrasi Ekstrak Daun Eboni dan Daun Sirsak Terhadap Retensi Bahan Pengawet pada Kayu Durian (Durio zibethinus)

Asniati, Muthmainnah — Thu, 29 Dec 2022 13:18:39 +0000

Durian wood is one type of wood that has a low level of durability, therefore it is necessary to make efforts to increase the durability of wood. These efforts can be done by preserving the durian wood by using natural preservatives, namely ebony leaves extract and soursop leaves. Ebony and soursop leaves extracts were used as natural preservatives with different concentrations using the cold soak method on durian wood. The research conducted aims to determine the effect of extract concentration on the retention of preservatives. Ebony leaves and soursop leaves were extracted by maceration method in 96% ethanol solvent for 24 hours. The durian wood sample was preserved using the cold soaking method for 1 hour using ebony leaves extract and soursop leaves extract at concentrations of 1%, 2%, and 3%. The results showed that the highest retention of preservatives from ebony leaves extract and soursop leaves extract was the use of 3% concentrations of 0.661 kg/m³ and 0.676 kg/m³, respectively. The results of the analysis of variance showed that the extract concentration had a significant effect on the retention value. The concentration of preservatives from ebony leaves extract and soursop leaves is directly proportional to the retention value of preservatives. Preservative retention of soursop leaves extract is better than ebony leaves extract.

Evaluasi Kadar Senyawa Fenolat, Flavonoid Total, serta Aktivitas Antioksidan Secara in vitro dalam Ekstrak Metanol Bawang Dayak (Eleutherine palmifolia (L.) Merr

Farida Laila, Ika Resmeliana, Wina Yulianti, Atep Dian Supardan — Thu, 29 Dec 2022 13:19:30 +0000

Dayak onion bulbs are a plant originating from Kalimantan which has been used for generations to treat various diseases. This plant is quite easy to grow and develop in many places in Indonesia. The aims of the present study were to evaluate the antioxidant potential of the methanol extract of Dayak onion bulbs based on the total of the phenolic and flavonoids contents and also the antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging ability, ferric reducing power and total antioxidant capacity. The results showed the total phenolic and flavonoid methanol extract of Dayak onion bulbs were 14.49 ± 1.42 mg GAE/g dry weight and 5.41 ± 1.01 mg QE/g dry weight, respectively. Antioxidant activity as measured by the DPPH, total antioxidant capacity, and ferric reduction assay with IC₅₀ values of 16.95 ± 1.58 μg/mL, 24.22 ± 2.51 µg/mL, and 85.40 ± 16.88 µg/mL, respectively. These results suggest that the methanol extract of Dayak onion bulbs has potential bioactive compounds with good antioxidant activity and can be developed as an effective and safe source of natural compounds for functional food or herbal medicine.

Analisis Kadar Merkuri (Hg) pada Rambut Pekerja Tambang di Pertambangan Emas Tanpa Ijin (PETI) Kabupaten Parigi Moutong dalam Hubungannya dengan Frekuensi Konsumsi Ikan

Musafira, Ernawaty Rasul — Thu, 29 Dec 2022 13:20:17 +0000

Illegal gold mining is a mining activity using traditional methods. Mining activities in the traditional way process mining products using the amalgamation process. In the amalgamation process, gold is bound by adding mercury and the waste from the amalgamation process which may still contain mercury is discharged into the environment. It can have an impact on the accumulation of mercury in humans, especially the miners either directly or through the food chain. This study aims to determine the amount of mercury concentration that has accumulated in miners' hair in relation to the frequency of fish consumption. The sampling method is done by random sampling method in five sub-districts in Parigi Moutong Regency. Fish consumption frequency data was taken by filling out questionnaires by respondents (miners). Analysis of mercury content in hair samples was carried out using the Mercury Analyzer NIC MA-3000. The results showed that the concentration of mercury in miners in all sub-districts exceeded the quality standard set by USEPA, which was above 1 mg/Kg. The highest mercury content was found in the miner's hair in Moutong District which was 3.48 mg/kg, while the lowest mercury content was found in the miner’s hair in Kasimbar District which was 1.06 mg/kg. Based on these results, the gold miners in the five sub-districts have been contaminated with mercury. A correlation value above 0.5 indicates a correlation between fish consumption and mercury concentrations in hair, thereby it can be said that the source of mercury exposure to miners can also come from the fish they consume.

Potensi Cangkang Telur Ayam dan Cangkang Telur Bebek sebagai Bioadsorben Logam Pb dari Limbah Cair Industri Farmasi

Lisna Dewi, Ginayanti Hadiesobroto, Hesty Nuur Hanifah — Thu, 29 Dec 2022 13:21:02 +0000

The pharmaceutical industry liquid waste is one of the wastes that have the potential to produce waste containing heavy metals. One of the highest metal contaminants originating from the pharmaceutical industry is lead (Pb). Pb metal can cause health problems and pollute the environment. One way to treat Pb waste is by the adsorption process using bioadsorbent. The eggshell waste can be used as an adsorbent to absorb heavy metals. The eggshell contains calcium carbonate, therefore it can be used as an adsorbent. This study aims to determine the optimum pH, optimum mixing time, and optimum mass of chicken eggshell powder and duck eggshell powder, and to determine the comparison of the effectiveness of adsorption between chicken eggshell powder and duck eggshell powder as bioadsorbent of heavy metal Pb in pharmaceutical industry wastewater by using Atomic Absorption Spectrophotometer (AAS) at a wavelength of 283.3 nm. The results showed that the eggshell samples had the optimum pH at pH 4, the optimum mixing time was 45 minutes, and the optimum mass was 125 mg, with the effectiveness of Pb adsorption of 92.75%. While the duck eggshell samples obtained the optimum pH at pH 2, the optimum mixing time was 30 minutes, and the optimum mass was 125 mg, with the effectiveness of Pb adsorption of 93.66%. Chicken and duck eggshells have the potential to be used as an alternative bioadsorbent in wastewater treatment.

Validasi Metode Penetapan Kadar Logam Kadmium (Cd) dalam Sampel Tanah Menggunakan Spektrofotometer Serapan Atom (SSA)-Nyala

Tita Rosita, Dewi Arfina Prasetyo Ningrum, Yuli Yanti, Zaekhan — Thu, 29 Dec 2022 13:22:07 +0000

Soil has an important role in life on earth because it supports plant life by providing nutrients and water as well as supporting roots. One of the chemical elements that cause pollution is cadmium. The standard method for analyzing the content of cadmium metal in the soil is using a Flame Atomic Absorption Spectrophotometer (AAS) referring to SNI 8910:2021. This method changes the weight content from one gram to five grams of sample to obtain cadmium metal levels that can be detected by the instrument. Therefore, this method needs to be validated before being used for routine analysis in the laboratory. The validation parameters are linearity, precision, accuracy, method detection limit, and robustness. The Validation results were obtained for the linearity parameter correlation coefficient value of r = 0.999, %RSD repeatability precision parameter of 1.51%, and the intermediate precision was obtained by %RSD analyst 1 : 1.51% and analyst 2 : 0.82%, accuracy parameter obtained the %recovery results were (88.73-97.01)%, the LDM parameter was obtained at 2.03 mg/kg, the robustness parameter was obtained by F-count of 1.25 and F-table of 3.40 which shows the average assay of metals Cd weighing 1, 3, 5, and 8 grams that were not significantly different. Overall, the results of the validation show that the method of assaying cadmium metal using Flame-AAS complies with the acceptance requirements, therefore it can be used for routine analysis in the laboratory.