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INDONESIA
PROSIDING SEMINAR KIMIA
Published by Universitas Mulawarman
ISSN : -     EISSN : -     DOI : -
Core Subject : Science,
Chemistry
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Articles 502 Documents
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APPLICATION OF KOKANG LEAVES (Lepisanthes amoena (Hassk) Leenh.) AS AN ANTIOXIDANT IN COOKING OIL Nurlaili, Nurlaili; Kamila, Adinda Putri; Valentina, Silva; Rahayu, Rosika; Pramalisa, Maria Cindy Amelia
PROSIDING SEMINAR KIMIA Vol 2 No 1 (2023): Prosiding SNK 2023
Publisher : Jurusan Kimia Fakultas Matematika dan Ilmu Pengetahuan Alam Universitas Mulawarman

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Abstract

Cooking oil is widely used by the public as a medium for frying food ingredients. Heating during frying causes a decrease in the quality of the oil due to an oxidation reaction. Oxidized fatty acids and the resulting peroxide compounds harm the health of the body. The rate of oil oxidation can be inhibited by adding antioxidants to the oil. The cock plant (L. amoena (Hassk) Leenh.) is a wild plant from West Kutai, East Kalimantan, which has a high antioxidant content. The use of kokang leaves as an antioxidant is expected to inhibit oxidation in cooking oil. This study aims to determine the antioxidant activity of kokang leaves in cooking oil when heated. Peroxide number is used as an indicator of the level of oxidation that occurs in the oil. Peroxide number was measured by iodometric titration using thiosulfate solution as titration. Peroxide number analysis was carried out on three samples, namely cooking oil before heating, cooking oil after heating, and cooking oil after heating which had been mixed with dry cockle leaves. Heating is done for 1 minute. The results showed that the peroxide value of cooking oil mixed with kokang leaves was lower than the peroxide value without being mixed with kokang leaves. This study indicates that kokang leaves can be used as an antioxidant to inhibit the oxidation process in cooking oil. Keywords: antioxidant, kokang leaf, Lepisanthes amoena (Hassk) Leenh.), iodometric titration
PYROLYSIS OF ULIN (Eusideroxylon zwageri) SAWDUST IN THE PRESENCE OF NI/SBA-15 USING A PYROLYSIS-GAS CHROMATOGRAPHY-MASS SPECTROSCOPY (PY-GC/MS) Marsella, Yuni; Subagyono, R. R Dirgarini J.N.; Gunawan, Rahmat
PROSIDING SEMINAR KIMIA Vol 2 No 1 (2023): Prosiding SNK 2023
Publisher : Jurusan Kimia Fakultas Matematika dan Ilmu Pengetahuan Alam Universitas Mulawarman

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Abstract

Pyrolysis study of Ulin (Eusideroxylon zwageri) sawdust in the presence of Ni/SBA-15 using a pyrolysis-gas chromatography-mass spectroscopy (Py-GC/MS) instrument has been carried out. This study aims to determine the chemical composition of pyrolysis products of Ulin sawdust after the addition of Ni/SBA-15 catalyst. Pyrolysis was carried out at 350, 450 and 550 ºC under helium (He) gas. Based on the percent area of the pyrolysis product identified on the pyrogram, the product of lignin derivatives before the addition of the Ni/SBA-15 catalyst was 58.53-68.14% and after the addition of the Ni/SBA-15 catalyst decreased to 51.08-58.33%. While the cellulose/hemicellulose derivative products before the addition of the Ni/SBA-15 catalyst were 15.62-17.78% and after the addition of the Ni/SBA-15 catalyst increased to 18.91-25.79%. Ulin sawdust catalyzed pyrolysis produced compounds with the highest area percent, namely catechol, isoelemicin, 2-Methoxy-4-vinylphenol, 1,6-anhydro-beta-D-Glucopyranose, and hydroxy-acetaldehyde. Keywords: pyrolysis, Eusideroxylon zwageri, Py-GC/MS, Ni/SBA-15 catalyst
KAJIAN STATUS MUTU AIR SUNGAI MAHAKAM SEGMEN KABUPATEN MAHAKAM ULU BERDASARKAN METODE STORET Solman, Solman; Bonifasius, Bonifasius; Kartika, Rudi; Gelung, Antonius; Ricard, Romoldus Jonius; Ilang, Yerwanto
PROSIDING SEMINAR KIMIA Vol 2 No 2 (2024): Prosiding SNKT III 2023
Publisher : Jurusan Kimia Fakultas Matematika dan Ilmu Pengetahuan Alam Universitas Mulawarman

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Abstract

Mahakam Ulu District is geographically located in the western part of East Kalimantan Province, where the Mahakam River flows. This upstream segment of the Mahakam River is the main river that functions as a transportation route, as raw water processed by Municipal Waterworks, used as a place for bathing, washing as well as serving as a lavatory by the community and a source of water for local community agriculture. Surface water sampling points consist of 14 stations, including ST I: Mahakam River (Long Pahangai Village), ST II: Melaseh River (Long Pahangai Village), ST III: Pahangai River (Long Pahangai Village), ST IV: Mahakam River (Tiong Ohang Village), ST V: Sebunut River (Long Bagun Village), ST VI: Alan River (Long Bagun Village), ST VII: Mahakam River (Ujoh Bilang Village), ST VIII: Melahan River (Long Melahan Village), ST IX: Mahakam River (Laham Village), ST X: Sungai Ratih (Damum Paroy village), ST XI: Mahakam River (Datah Bilang village), ST XII: Pari River (Datah Bilang village), ST XIII: Pataq River (Long Bagun sub-district) and ST XIV: Medang River (Long Bagun sub-district). Determination of water quality status using the STORET Method or Pollution Index Method. The STORET method is one of the commonly used methods for determining water quality status. With this STORET method can be known parameters that have met or exceeded water quality standards. From the results of the study, the water quality parameters that partially did not meet the class I quality standards were 6 parameters, among others: TSS, BOD, COD, DO and Faecal coliform and Total coliform, while for classes II, III and IV all parameters meet the quality standards according to regulations. Keywords: Activities around the river, river quality status, STORET Method
A KINETIC STUDY OF PYROLYSIS OF BAGASSE USING THERMOGRAVIMETRIC ANALYSIS Rachmawanti, Octaviana; Subagyono, R.R. Dirgarini; Allo, Veliyana Londong
PROSIDING SEMINAR KIMIA Vol 2 No 1 (2023): Prosiding SNK 2023
Publisher : Jurusan Kimia Fakultas Matematika dan Ilmu Pengetahuan Alam Universitas Mulawarman

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Abstract

A kinetic study of pyrolysis of bagasse using thermogravimetric analysis using the model-free methods, including the Kissinger-Akahira-Sunose (KAS) method and the Friedman method, has been carried out. The purpose of this study was to determine the pyrolysis decomposition process of bagasse and to determine the activation energy value of pyrolysis of bagasse. In this study, pyrolysis was carried out at various heating rates of 10, 15, 20, and 25 °C/minute using a Thermogravimetric Analyzer (TGA). The active pyrolysis temperature range of bagasse was + 104-431°C with a mass reduction of 56-64% where the decomposition process of cellulose, hemicellulose, and lignin in the biomass sample occurred. The activation energy obtained based on the KAS was 136.39 + 23.19 kJ/mol, wheres the activation energy obtained based on the Friedman method was 156.19 + 35.28 kJ/mol. Keywords: Bagasse, Pyrolysis, Thermogravimetry, Model-free, Activation Energy
AKTIVITAS DAN STABILITAS FISIK LOSION TABIR SURYA DARI EKSTRAK DAUN RAMBAI (Sonneratia caseolaris (L.)engl.) Warnida, Husnul; Ardita, Ardita; Nurhasnawati, Henny; Sukawaty, Yullia
PROSIDING SEMINAR KIMIA Vol 2 No 2 (2024): Prosiding SNKT III 2023
Publisher : Jurusan Kimia Fakultas Matematika dan Ilmu Pengetahuan Alam Universitas Mulawarman

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Abstract

Long-term, intense sun exposure can cause erythema and sunburn, as well as premature aging and skin cancer. For generations, the people of the Banjar tribe of Borneo have applied a wet paste of Sonneratia caseolaris leaves mixture on the skin when undertaking tasks in the hot sun. The Sonneratia caseolaris tree is a mangrove plant that grows on river banks throughout the Borneo Island. The study aims to formulate Sonneratia caseolaris leaves ethanol extract into a stable lotion and test its efficacy as a sunscreen. Sonneratia caseolaris leaves were macerate with 70% ethanol, and the sunscreen activity of the extract was examined in vitro with a UV-visible spectrophotometer, and then formulated into a lotion dosage form. Organoleptic and homogeneity observations, pH measurements, viscosity measurements, and spreadability measurements were all performed on the lotion. Following that, the lotion sunscreen activity of was tested in vitro. The Sonneratia caseolaris extract sunscreen lotion has met the requirements of organoleptic, homogeneity, pH, viscosity, and spreadability tests. Sunscreen lotion with 2.5% Sonnerata caseolaris extract classified as standard suntan. Sonneratia caseolaris extract of Borneo has the potential to develop as a raw material for herbal cosmetics. Keywords : Sonneratia caseolaris, mangrove, lotion, sunscreen, suntan
SYNTHESIS OF SILVER NANOPARTICLES USING BIOREDUCTORS: MINI REVIEW Indriani, Isah Waliah; Hindryawati, Noor; Hiyahara, Irfan Ashari
PROSIDING SEMINAR KIMIA Vol 2 No 1 (2023): Prosiding SNK 2023
Publisher : Jurusan Kimia Fakultas Matematika dan Ilmu Pengetahuan Alam Universitas Mulawarman

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Abstract

Synthesis of silver nanoparticles can be carried out using bioreductors which are natural reducing agents from natural materials containing antioxidant compounds or polyols which can reduce silver due to the nucleophilic nature of phenolic compounds in plant secondary metabolites. The use of bioreductors in the manufacture of nanoparticles can reduce the adverse effects and hazardous waste generated due to reduced adsorption of the toxic properties of the solvent used. The content of organic compounds in bioreductors can be utilized, for example secondary metabolites such as terpenoids, flavonoids and tannins which act as antioxidants and capping agents, where Ag+ ions in AgNO3 can be reduced into silver nanoparticles, so bioreductors can replace the role of synthetic reducing agents. Based on the literature used, several plants whose extracts can be used as bioreductors, namely gambier, gotu kola leaves, water hyacinth leaves, bilimbi leaves, cempedak bark and bay leaves using variations in the concentration and composition of the AgNO3 solution. The results of silver nanoparticles were synthesized using bioreductors, namely various nano-sized particles and based on UV-Vis spectrophotometry data, silver nanoparticles appeared at wavelengths between 410 - 450 nm. Keywords: Secondary metabolites, Bioreductors, Silver Nanoparticles
THE EFFECTIVENESS OF THE USE OF CHEMCOLLECTIVE VIRTUAL LABORATORY MEDIA WITH GUIDED INQUIRY LEARNING MODELS ON STUDENT LEARNING OUTCOMES ON ACID-BASE TITRATION MATERIAL Theresia, Clara; Hartati, Yuli; Lestari, Sri
PROSIDING SEMINAR KIMIA Vol 2 No 1 (2023): Prosiding SNK 2023
Publisher : Jurusan Kimia Fakultas Matematika dan Ilmu Pengetahuan Alam Universitas Mulawarman

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Abstract

This study aims to determine the effectiveness of using ChemCollective virtual laboratory media with guided inquiry learning models on student learning outcomes on acid-base titration material. The subjects of this study were XI MIA 1 and XI MIA 2 classes totaling 59 students. The research subjects were selected using saturated sampling technique. This research method is pre-experiment with one group pretest-posttest design. Data collection used tests in the form of pre-test and post-test and student response questionnaires which were then analyzed using the N-Gain test and effect size test. The results showed that the use of virtual laboratory media was effective for improving student learning outcomes with an N-Gain value of 0.5022 which was classified as moderate and the level of effectiveness was classified as very strong with an effect size value of 1.5716. Keywords: Effectiveness, Virtual Laboratory, Learning Outcomes, Acid-Base Titration
THE EFFECTIVENESS OF STEM AND RHIZOME EXTRACT OF KECOMBRANG (Etlingera elatior) AS A NATURAL PRESERVATIVE FOR TILAPIA (Oreochromis niloticus) MEAT Hernanda, Tasya; Nurlaili, Nurlaili; Noviyanti, Putri; Syafira, Irmaina; Aprilia, Lisa; Rofiah, Is Nur Dwi; Darmayanti, Citra
PROSIDING SEMINAR KIMIA Vol 2 No 1 (2023): Prosiding SNK 2023
Publisher : Jurusan Kimia Fakultas Matematika dan Ilmu Pengetahuan Alam Universitas Mulawarman

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Abstract

Tilapia contains protein and has a high nutritional content, including minerals, vitamins and unsaturated fats. However, this fish is easily damaged and rotten. This is caused by the activity of enzymes, microorganisms, or oxygen oxidation. Therefore, it is necessary to use preservatives so that the fish does not spoil or rot quickly. One of the potential natural preservatives is the kecombrang plant, especially the stems and rhizomes which contain bioactive substances. This plant has antibacterial properties that can help slow down the decline in fish quality. This study aims to determine the effectiveness of kecombrang stem and rhizome extract as a natural preservative in tilapia meat. The effectiveness of kecombrang stem and rhizome extracts was determined by soaking tilapia meat in kecombrang stem and rhizome extracts at various times of 0, 3, and 6 hours. The protein content of tilapia meat was measured by the biuret test. The results of this study indicated that the percentage of protein degradation inhibitors in kecombrang stem extract was 30.1% for 3 hours and 17.8% for 6 hours while in kecombrang rhizome extract was 34.2% for 3 hours and 22.6% for 6 hours. This shows that kecombrang rhizome extract is more effective as a natural preservative for tilapia meat compared to kecombrang stem extract. Keywords: Tilapia, kecombrang stem, kecombrang rhizome, natural preservative, biuret
MINI REVIEW: SINTESIS DAN KARAKTERISASI NANOPARTIKEL CaO DARI CANGKANG TELUR MENGGUNAKAN METODE KALSINASI Zahra, Marinda Afifatu; Hiyahara, Irfan Ashari; Syaima, Husna
PROSIDING SEMINAR KIMIA Vol 2 No 2 (2024): Prosiding SNKT III 2023
Publisher : Jurusan Kimia Fakultas Matematika dan Ilmu Pengetahuan Alam Universitas Mulawarman

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Abstract

This review article aims to collect, compare and analyze the latest research on the synthesis and characterization of CaO nanoparticles from eggshells. CaO is a material in the form of white crystalline solids made from thermal decomposition of limestone or shells, which contains CaCO3 which has the potential to become CaO nanoparticles to be applied in various fields. Currently, various methods have been carried out to synthesize these materials, such as precipitation methods, hydrothermal methods, sol-gel methods, and so on. One of them is the calcination method. The calcination method itself is a commonly used thermal processing method involving heating at high temperatures. The advantages of the calcination method are that it is efficient, has a high level of purity, is economical and relatively simple and others. However, the calcination method itself has disadvantages, namely the process time is quite long, must be careful and can have a negative impact on the environment. In this review, we will discuss the synthesis of CaO nanoparticles characterized using X-Ray Diffraction (XRD), Fourier Transform InfraRed (FTIR), Scanning Electron Microscope (SEM), Transmission Electron Microscope (TEM). The literature results show that in XRD the main peak 2θ positions are 111 and 200 and the crystal size is 10-55 nm, in FTIR the functional groups that appear are the Ca-O stretch group and C-O stretch vibrations, in SEM and TEM the shape of the crystal. Keywords: Synthesis, CaO nanoparticles, Calcination
PROBLEM BASED LEARNING (PBL) TOWARDS STUDENTS' CRITICAL THINKING ABILITY: LITERATURE REVIEW Nasriati, Nasriati; Winarni, Sri; Hanum, Latifah
PROSIDING SEMINAR KIMIA Vol 2 No 1 (2023): Prosiding SNK 2023
Publisher : Jurusan Kimia Fakultas Matematika dan Ilmu Pengetahuan Alam Universitas Mulawarman

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Abstract

Following the learning objectives of the 21st century, the learning process emphasizes mastery of teaching materials and requires direct students to solve problems. Critical thinking skills are needed for students to be able to solve problems. Problem-based learning is learning that emphasizes presenting authentic problems based on phenomena in everyday life. This literature review aims to discover the importance of applying the PBL learning model to improve students' critical thinking skills in chemistry learning. The method used in this study is a literature review beginning with finding topics to make it easier to collect data. Data were obtained by searching journals through Google Scholar and Science Direct, published for the last ten years (2012-2022) using the keywords PBL, critical thinking skills, and chemistry. Based on the literature search, 15 relevant articles have been found for further analysis. The literature review results show that applying PBL learning has strong potential to improve students' critical thinking skills in various fields of study, especially chemistry. Keywords: Chemistry, Critical Thinking, PBL

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