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Penggunaan Electrode Grafit Pensil Secara Voltammetri Differential Pulse Untuk Analisis Kadmium Dalam Sampel Ikan Cakalang (Katsuwonus Pelamis) Fufu Marlina Karundeng; Vlagia Paat; Stefan Rumengan
Jurnal Kimia Fullerene Vol 7 No 1 (2022): Fullerene Journal of Chemistry
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.37033/fjc.v7i1.510

Ikan kayu atau skipjack tuna (Katsuwonus pelamis), adalah salah satu komoditas perikanan Indonesia yang lebih dikenal dengan sebutan lokal Cakalang fufu, yang memiliki nilai ekonomis tinggi dan mampu menembus pasar internasional. Di Sulawesi Utara khusunya sumber daya ikan jenis ini mencapai 459.800 ton/tahun. Berdasarkan laporanFDA (Food and Drug Administration) dari tahun 2001-2005 terdapat 350 penolakan pada produk tuna Indonesia, alasannya karena kandungan logam beratnya, diantaranya kadmium yang melebihi ambang batas. Tujuan dari penelitian ini adalah untuk pengembangan metodde voltammetry dalam menentukan kandungan cadmium dalam sampel ikan cakalang fufu dengan menggunakan grafit pensil sebagai electrode kerja dan menentukan batas deteksi metode ini dalam mendeteksi cadmium. Sampel daging ikan cakalang yang akan diperiksa diambil dari Pasar Tradisional Amurang Kabupaten Minahasa Selatan , provinsi Sulawesi Utara. Sampel dipreparasi setelah itu didestruksi menggunakan asam nitrat, asam perklorat, dan hydrogen peroksida. Sampel hasil destruksi kemudian dianalisis dengan metode voltammetry pulsa diferensia lmenggunakan grafit pensil sebagai electrode kerja dengan penambahan standar dimana kondisi kerja diatur untuk pembacaan dari potensial -1,0 V sampai 1,2 V. Dari penelitian ini diperoleh hasil bahwa metode voltammetri menggunakan elektrode grafit pensil dapat mendeteksi kadmium (II), rata-rata perolehan kembali 50%. Konsentrasi kadmium dalam sampel ikan cakalang fufu yang diperoleh dengan metode voltammetri menggunakan elektrode grafit pensil adalah 2,2 ppm.

Synthesis of Iodo Quinolinone Stefan Marco Rumengan; Khoirotul Ummah
Jurnal Kimia Fullerene Vol 8 No 1 (2023): Fullerene Journal of Chemistry
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.37033/fjc.v8i1.500

Quinolones are important heterocyclic compounds in medicine and materials for DSSC or OLED. This study aims to make a quinolinone framework that has several functional groups. These functional groups can be coupled with various other heterocyclic compounds. The synthesis of the target compound consists of forming a quinolinone framework using phenyldiamine and ethyl aceto acetate via the Penchmann reaction then iodination using ICl. The Penchmann reaction succeeded in forming a quinolinone framework as indicated by shown a proton signal at 11.22 ppm. The iodination reaction was successfully carried out by adding iodo to the benzene ring and the appearance peak of (M+H) m/z was 300.9839 on mass spectroscopy. The compound 7-amino-8-iodo-4-methyl-2-quinolinone (compound 2) has been successfully synthesized. Compound 2 has 3 functional groups (amine, iodo and alkene) that can be used for coupling with the other heterocycles.

EFFECT OF POTASSIUM HYDROXIDE CONCENTRATION AS A CATALYST ON THE YIELD OF COCONUT OIL (Cocos nucifera) TRANSESTERIFICATION Chaleb Paul Maanari; Sanusi Gugule; Feti Fatimah; Aisyiah Restutiningsih Putri Utami; Mustapa Mustapa; Stefan Marco Rumengan; Miftahul Jannah; Jakub Saddam Akbar; Djois Sugiaty Rintjap
Indonesian Journal of Pure and Applied Chemistry Vol 6, No 3 (2023)
Publisher : Tanjungpura University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26418/indonesian.v6i3.65513

Research has been carried out on the effect of potassium hydroxide catalyst concentration on the yield of coconut oil (Cocos nucifera) transesterification and continued to characterize the reaction results. The concentration of potassium hydroxide used was 1, 2, and 3% by weight of coconut oil with ethanol as the reactant. The data processing used was the one-way analysis of variation and its characterization from a physicochemical perspective, followed by the analysis of gas chromatography-mass spectroscopy (GCSM) and infrared spectrophotometry. Based on the data processing results, potassium hydroxide concentrations of 1, 2, and 3% did not affect the yield of the transesterification reaction of coconut oil, and the results were 74.5264%, 71.9330%, and 69.0420%. The characterization results show that the physicochemical properties of the reaction products, such as acid number, density, and viscosity, comply with the Indonesian National Standard (SNI) for biodiesel. The results of the GCMS analysis showed that nine peaks were dominated by ethyl laurate.

Synthesis of Diazo Quinolinone Stefan Marco Rumengan; Khoirotul Ummah; Robby Gus Mahardika; Ana Mardliyah; Mariam Ulfah; Ajeng Triane Syawila
Jurnal Kimia Fullerene Vol 8 No 2 (2023): Fullerene Journal of Chemistry
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.37033/fjc.v8i2.600

Quinolones are important heterocyclic compounds in medicine and materials for DSSC or OLED. This study aims to make a quinolinone framework that has several functional groups. These functional groups can be coupled with various other heterocyclic compounds. The synthesis of the target compound consists of forming a quinolinone framework using phenyldiamine and ethyl aceto acetate via the Penchmann reaction then iodination using ICl. The Penchmann reaction succeeded in forming a quinolinone framework as indicated by shown a proton signal at 11.22 ppm. The iodination reaction was successfully carried out by adding iodo to the benzene ring and the appearance peak of (M+H) m/z was 300.9839 on mass spectroscopy. The compound 7-amino-8-iodo-4-methyl-2-quinolinone (compound 2) has been successfully synthesized. Compound 2 has 3 functional groups (amine, iodo and alkene) that can be used for coupling with the other heterocycles.

Penerapan Flipped Classroom dalam Peningkatan Hasil Belajar Ikatan Kimia pada Kuliah Kimia Dasar Stefan Marco Rumengan; Jakub Saddam Akbar; Yana Sambeka; Vlagia Paat
Oxygenius: Journal Of Chemistry Education Vol 5 No 2 (2023): Oxygenius : Journal Of Chemistry Education
Publisher : Chemistry Department, Universitas Negeri Manado

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.37033/ojce.v5i2.621

Flipped classroom is a learning approach where subject matter and skills that are usually taught during class hours are delivered outside the classroom. This research aims to determine differences in student learning outcomes through the application of the flipped classroom learning model on basic chemistry material in mathematics education at Universitas Negeri Manado (Unima). This research is quantitative research using experimental methods with a one-group pretest-posttest design. The sample used in this research was class A mathematics education students with a low or no level of understanding of chemistry. The data collection technique uses a learning outcomes test where a pretest is given before the lecture process is carried out and a posttest after the lecture process is carried out. The research results showed that the average student learning outcomes in the pre-test were 37.71 and the average student learning outcomes in the post-test were 87.88. The N-Gain score test results show a score of 81% which is included in the effective and high category. Based on these results, it can be concluded that the application of the flipped classroom model improves student learning outcomes in chemical bond material in the general chemistry class at Unima’s mathematics education effectively and significantly.

THE INFLUENCE OF HEAVY METALS ON THE ABSORPTION OF CATIONIC DYES Mustapa Mustapa; Aisyiah Restutiningsih Putri Utami; Chaleb Paul Maanari; Miftahul Jannah; Stefan Marco Rumengan
JURNAL PENA SAINS Vol 11, No 1 (2024): Jurnal Pena Sains
Publisher : Program Studi Pendidikan IPA, Fakultas Ilmu Pendidikan, Universitas Trunojoyo Madura

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.21107/jps.v11i1.24999

Cationic dyes are dyes containing amine derivatives that can be used on cellulose, protein, nylon, acrylic and synthetic fibers but these dyes are less fast in coloring. This study investigates the impact of Pb2+ heavy metal ions on cationic dye absorption utilizing molecularly imprinted polymers as adsorbents. Concentrations of Pb2+ ranging from 0 to 50 mg/L were examined. In a one-hour interaction, 50 mg of adsorbent was introduced into a solution containing 100 ppm methylene blue dye and Pb2+ with varying concentrations. Following centrifugation, the filtrate was collected, and dye concentration was measured using a visible light spectrophotometer. The sorption capacity of the dye with Pb2+ reached 41.22 mg/g at the highest concentration and 35.83 mg/g at the lowest. Notably, an inverse relationship was observed between Pb2+ concentration and absorption capacity, indicating a decrease as metal ion concentration increased, though stability was maintained. These findings contribute valuable insights into the nuanced dynamics of heavy metal ions and cationic dye absorption, shedding light on potential applications of molecularly imprinted polymers as effective adsorbents.

Isolation and Identificationof Octadecane-3-on Compound From Ethyl Acetate Fraction of Momordica balsamina L. Leaves Emma Julien Pongoh*; Rymond Jusuf Rumampuk; Vlagia Indira Paat; Stefan Marco Rumengan; Julieta Soputan
JIPI (Jurnal IPA dan Pembelajaran IPA) Vol 8, No 1 (2024): March 2024
Publisher : Universitas Syiah Kuala

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24815/jipi.v8i1.37717

Momordica balsamina L. is a wild plant that generally grows in moist soil and gets a lot of sunlight. The leaves and fruit are reported to have various medicinal and nutritional properties. This study aimed to isolate and identify the compounds contained in the ethyl acetate fraction in Momordica balsamina L The isolation stage was carried out by the maceration method and the separation and purification of the compounds using gravity column chromatography methods to obtain isolate fraction F1.6.2 with a sample weight of 2.4 mg. Identification of compounds using proton nuclear magnetic resonance (1H-NMR) and carbon nuclear magnetic resonance (13C-NMR) spectroscopy techniques. The proposed identified compound is octadecan-3-one or 3-octadecanone with the molecular formula C18H36O

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