KOVALEN: Jurnal Riset Kimia
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Validasi Metode Analisis Iodin Secara Spektrofotometri UV-Vis pada Dua Variasi Pelarut: Validation of The Method of Iodin Analysis by Uv-Vis Spectrofotometry with Two Variations of Solution
Full text linkIn this study, the method of analysis of iodine by UV-Vis spectrophotometry was validated. Two other solvents, ethanol, and cyclohexane were used to validate this approach. The UV-Vis Spectrophotometer method's linearity, detection, and quantization limitations, precision, and accuracy were investigated as variables. The results of the linearity tests indicated that the method was proportionally verified because the r values for the two iodine solutions in ethanol and cyclohexane varied between 0.990 and 0.999, respectively. This suggests that the values were higher than 0.99. The LOD values for the ethanol solvent were 4.441 mg/kg and the LOQ was 14.802 mg/kg, whereas the cyclohexane solvent had an LOD value of 2.660 mg/kg and the LOQ was 8.866 mg/kg. According to the required precision acceptance, the %RSD value of 2%, precision values for both standard iodine solutions with two modifications of solvents demonstrated good results. Recovery percentages of ethanol solvents are 96% and cyclohexane solvents are 86%, respectively, according to accuracy measurements. The combined uncertainty value for this test is 0.109 for the ethanol solvent and 0.019 for the cyclohexane solvent, respectively. This research provides a comprehensive understanding of the validity of the iodine analysis method, establishing a robust foundation for the sustainability and reliability of using UV-Vis spectrophotometer in the analysi
Determination of Boron Concentration at Sausage Samples with Distillation of Ester Borane Method using Fluorescence Spectrophotometry
Full text linkThe study of borax contamination in food samples was successfully analyzed. This study used sausage samples using the Fluorescence Spectrophotometry method. Sausage samples were from Daerah Istimewa Yogyakarta (DIY). This study used 4 sausage samples. The samples were given labels A, B, C, and D. The steps of the research were optimation of distillation time, optimation of catalyst, optimation of solvent, and then followed by analyzing the borax concentration on sausage samples. Based on this study, the optimum distillation time was 24 hours. On the other hand, the best catalysts and solvents were sulphuric acid and ethanol. The A and B samples contained borax contamination and the concentration was under 5 ppm. The C and D samples contained borax contamination and the concentration was above 5 ppm. The conclusions were that A and B samples were not given borax addition and C and D samples were given borax addition
Laju Korosi Logam Baja Karbon Rendah di Larutan Garam pada Berbagai Konsentrasi Inhibitor Korosi dari Ekstrak Daun Pepaya: Low Carbon Steel Metal Corrosion Rate in Salt Solution at Various Concentrations of Corrosion Inhibitor from Papaya Leaf Extract
Full text linkPapaya 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 (Carica papaya) 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 FeCl3 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 45â°C to 55â°C 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
Pemanfaatan Karbon Aktif Kulit Kacang Tanah untuk Menurunkan Kadar Ion logam Ca2+ dan Mg2+ dalam Air: Utilization Peanut Shell Activated Carbon to Reduce Levels of Ca2+ and Mg2+ in Water
Full text linkPeanut 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 Ca2+ and Mg2+ 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 Ca2+ levels by 77.46% -84.89% and Mg2+ by 86.88%-88.91%. Adsorbents with variations in pH can reduce Ca2+ levels by 63.48%-88.74% and Mg2+ by 90.35%-94.49%. The best conditions for the absorption of Ca2+ and Mg2+ ions were a contact time of 60 minutes and pH 4. The adsorbent was applied to reduce Ca2+ and Mg2+ levels in water with different hardness levels. The results of the analysis of water samples from two different locations had Ca2+ levels of 94.180 mg/L and 210.20 mg/L, while Mg2+ levels were 13.536 mg/L and 17.420 mg/L. The percentages of Ca2+ adsorption for the two samples were 96.19% and 77.08%, and the percentages of Mg2+ 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
Pengolahan Air Limbah Tahu Menggunakan Metode Elektrokoagulasi dan Adsorpsi Secara Kontinyu: Tofu Wastewater Treatment Using Continuous Electrocoagulation and Adsorption Method
Full text linkTofu 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
Ekstraksi Gelatin dari Tulang Ikan Tongkol (Euthynnus affinis) dengan Menggunakan Asam Belimbing Wuluh (Averrhoa bilimbi L): Gelatin Extraction from Tongkol Fish Bone (Euthynnus affinis) using Acid from Starfruit (Averrhoa bilimbi L)
Full text linkGelatin is a type of protein resulting from the partial hydrolysis of collagen found in animals' skin, bones, and connective tissue. Gelatin is widely used in the food and pharmaceutical industries. Using Tongkol fish bones as a source of gelatin is a safe alternative for the human body and halal for consumption. Characteristics of gelatin from the bone waste of Tongkol fish extracted with starfruit acid are important to know, therefore it can be used as a substitute for cow and pork skin. The purpose of this study was to determine the characteristics of Tongkol fish bone gelatin extracted with tamarind starfruit. The extraction method was used in this research using 5 levels of starfruit acid concentration (10%, 20%, 30%, 40%, 50%) with the ratio of solvent and fish bones 1: 4 (w/v). The use of starfruit acid with a concentration of 40% produced the highest yield with the characteristics of the resulting gelatin having a brownish yellow color, yield of 1.43%, water content of 17%, ash content of 15%, degree of acidity (pH) of 6.5 and protein content of 47.98%. 
Penggunaan Arang Aktif Ampas Kopi untuk Menurunkan Bilangan Peroksida dan Asam Lemak Bebas (ALB) pada Minyak Goreng Bekas : Utilization of Activated Charcoal from Coffee Grounds to Reduce Peroxide Number and Free Fatty Acid (FFA) in Used Cooking Oil
Full text linkThe peroxide value and free fatty acid content influence the quality of cooking oil. Activated charcoal from coffee grounds has been used in processing used cooking oil. This research aimed to determine the ratio of coffee grounds activated charcoal adsorbent-to-used cooking oil (w/v) and the optimum contact time to reduce used cooking oil's peroxide and free fatty acid levels. The ratio of adsorbent and used cooking oil was 1:20, 1:10, and 1:5 (w/v) with contact times of 60, 90, and 120 minutes. Coffee grounds charcoal was activated by ZnCl2. A ratio of adsorbent and cooking oil 1:5 (10 g activated carbon and 50 ml cooking oil) reduced the peroxide number from 12 mek/O2 kg to 9.8 mek/O2 kg and free fatty acids from 0.972% to 0.383%. A contact time of 120 minutes could optimally reduce the peroxide number and free fatty acids from 12 mek O2/kg to 9.3 mek O2/kg and 0.972% to 0.332%, respectively. Coffee grounds have the potential to be processed into activated charcoal for refining used cooking oil
Pembuatan Konsentrat Protein Ampas Tahu Menggunakan Garam Ammonium Sulfat: Manufacturing of Tofu Pulp Protein Concentrate Using Ammonium Sulphate
Full text linkTofu 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
Full text linkThis 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
Penurunan Kadar Chemical Oxygen Demand (COD) pada Limbah Cair Industri Tahu Menggunakan Arang Aktif dari Pelepah Kelapa Sawit (Elaeis guenensis Jacq.) : Reducing Chemical Oxygen Demand (COD) Levels in Tofu Industrial Liquid Waste Using Activated Charcoal from Palm Oil (Elaeis guenensis Jacq.) Mid-ribs
Full text linkOil palm midribs (Elaeis guenensis Jacq.) are one of the wastes from oil palm plantations. The high carbon element composition in the palm midribs has the potential to be used as charcoal or activated carbon. Activated carbon can reduce COD levels in tofu industrial wastewater. This study aims to determine the effect of activated carbon mass and contact time on decreasing COD levels in tofu industrial wastewater. Palm midrib charcoal was activated using HCl 1N with the independent variable of activated charcoal mass (1, 3, 5, 7, and 9 grams) and contact times (30, 60, 90, 120, and 150 minutes), while the dependent variable was the percentage decrease COD levels. Activated charcoal from the palm midribs was in accordance with SNI 06-3730-1995 concerning the Quality Standard of Activated Charcoal. The effect of the adsorbent mass showed that the mass increase in activated charcoal was directly proportional to the percentage decrease in COD levels in the tofu industrial wastewater, while the optimum contact time of activated charcoal was obtained at 60 minutes with a decrease in COD levels of 82.13%