Alchemy: Jurnal Penelitian Kimia最新文献

{"title":"Adsorpsi Anilin oleh Karbon Aktif Magnetik Cangkang Kelapa Sawit","authors":"Hani Alfiyani, Nurlina Nurlina, Nelly Wahyuni","doi":"10.20961/alchemy.18.2.53647.130-139","DOIUrl":"https://doi.org/10.20961/alchemy.18.2.53647.130-139","url":null,"abstract":"Karbon aktif merupakan salah satu adsorben yang dapat dikompositkan dengan besi oksida menjadi karbon aktif magnetik (KAM) sehingga mempermudah proses pemisahannya dari dalam larutan. Penelitian ini menjelaskan kinerja KAM dalam mengadsorpsi anilin dengan menentukan isoterm dan kinetika adsorpsinya serta efektifitas sifat magnet dalam pemisahan KAM. Karbon aktif magnetik dibuat dari cangkang kelapa sawit dikarbonisasi (300 ºC, 2 jam), diaktivasi fisika (600 ºC, 30 menit), dan dilanjutkan aktivasi kimia (ZnCl2 0,05 M). Karbon aktif magnetik dibuat dengan mencampurkan karbon aktif dan larutan Fe(III)/Fe(II) (rasio mol 2:1). Pengukuran daya serap adsorpsi menggunakan variasi konsentrasi anilin (25, 50, 75, 100, dan 125 ppm) dan waktu kontak (60, 120, 180, 240, dan 300 menit). Adsorben KAM dikarakterisasi menggunakan spektrofotometer infra merah (FTIR), difraktometer sinar-X (XRD), fluoresensi sinar-X (XRF), Surface Area Analysis (SAA) dan konsentrasi anilin diukur dengan spektrofotometer UV-Vis. Hasil analisis FTIR menunjukkan munculnya serapan Fe-O pada bilangan gelombang 580,32 cm-1 yang mengindikasikan adanya besi oksida pada KAM. Difraktogram XRD menunjukkan puncak pada 2θ 18,39º; 34,09º; 34,82º; 35,03º; dan 35,87º dari magnetit Fe3O4, puncak 2θ 32,83º; 35,77º; dan 38,18º dari hematit. Hasil SAA menunjukkan luas permukaan KAM 179,40 m2/g, diameter rata-rata pori 24,95 Å dan XRF menunjukkan adanya kandungan Fe2O3 pada KAMsebesar 76,316%. Kapasitas adsorpsi optimum diperoleh pada konsentrasi anilin 100 ppm dengan waktu kontak selama 240 menit sebesar 86,254 mg/g. Kinetika adsorpsi sesuai dengan model pseudo-orde dua (R2 sebesar 0,9934) dengan konstanta kinetika 0,0073 g/(mg.menit).Aniline Adsorption by Oil Palm Shell Magnetic Activated Carbon. Activated carbon is one of the adsorbents that can be composted with iron oxide into magnetic activated carbon (KAM), making it easier to separate from the waste solution. This research investigated the KAM's performance in absorbing aniline by determining its adsorption isotherms and kinetics as well as the effectiveness of magnetic properties in KAM separation. Magnetic activated carbon was produced by oil palm shells carbonization at (300 ºC, 2 hours), followed by physical activation (600 ºC, 30 minutes), and continued by chemical activation (ZnCl2 0.05 M). Magnetic activated carbon was made by mixing activated carbon and Fe(III)/Fe(II) solution (mole ratio 2:1). Adsorption measurements use variations in aniline concentrations (25, 50, 75, 100, and 125 ppm) and contact times (60, 120, 180, 240, and 300 minutes). KAM adsorbents were characterized using infrared spectrophotometers (FTIR), X-ray diffractometers (XRD), X-ray fluorescence (XRF), and surface area analysis (SAA). Meanwhile, the adsorbed aniline concentrations were measured by UV-Vis spectrophotometers. The results of the FTIR analysis showed the appearance of Fe–O absorption in wavenumbers 580.32 cm-1 indicating the presence of iron oxide in KAM","PeriodicalId":7926,"journal":{"name":"Alchemy: Jurnal Penelitian Kimia","volume":"13 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86780343","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sintesis dan Karakterisasi Membran Selulosa Asetat dengan Penambahan Antibiofouling Alami Ekstrak Bawang Putih","authors":"Dikianur Alvianto, Fara Aulia Agustin Nurhadi, Angky Wahyu Putranto, Bambang Dwi Argo, M. Hermanto, Yusuf Wibisono","doi":"10.20961/alchemy.18.2.57199.193-204","DOIUrl":"https://doi.org/10.20961/alchemy.18.2.57199.193-204","url":null,"abstract":"Teknologi membran merupakan teknologi yang dapat memisahkan dua fasa (permeat dan umpan). Kendala dalam teknologi membran yaitu bahan yang terkandung dalam umpan dan mengakibatkan terjadinya fouling (penutupan pori). Salah satu alternatif untuk mengurangi fouling yaitu menambahkan zat antibiofouling pada membran. Bahan yang dapat digunakan sebagai antibiofoulan alami adalah ekstrak bawang putih yang memiliki sifat antibakteri. Penelitian ini bertujuan untuk menganalisis pengaruh penambahan ekstrak bawang putih terhadap perbaikan karakteristik membran (ketebalan, kuat tarik, elastisitas), fluks air bersih, dan sifat antibiofouling pada bakteri Bacillus subtilis. Membran selulosa asetat dibuat dengan menggunakan metode inversi fasa dan pelarut dimetilformamida. Penambahan ekstrak bawang putih pada pembuatan membran selulosa asetat memiliki konsentrasi masing-masing sebesar 0,25% b/v (0,01 g), 0,5% b/v (0,02 g), 0,75% b/v (0,03 g), dan 0% b/v (kontrol) dengan ketebalan 0,3 mm. Hasil yang optimum diperoleh untuk membran dengan konsentrasi 0,5 % b/v yang menghasilkan pengujian kuat tarik sebesar 0,977 N/mm2 dan untuk membrane dengan konsentrasi 0,25% b/v yang memberikan elastistas pertambahan panjang sebesar 12,22%. Sifat antibakteri membran dengan penambahan ekstrak bawang putih ditunjukkan dengan berkurangnya penempelan bakteri Bacillus subtilis pada permukaan membran sebesar 41,5% – 87,7% area.Synthesis and Characterization of Cellulose Acetate Membrane with The Addition of Natural Antibiofouling Garlic Extract. Membrane technology is a technology that can separate two phases (permeate and feed). The main problem in membrane technology is the material contained in the feed, which causes fouling (pore closure). An alternative to reducing fouling is by adding anti-biofouling substances into the membrane. The material that can be used as a natural anti-biofoulant is garlic extract which has antibacterial properties. This study aimed to analyze the effect of adding garlic extract on the improvement of membrane characteristics (thickness, tensile strength, elasticity), clean water flux, and anti-biofouling properties of Bacillus subtilis bacteria. The cellulose acetate membrane was synthesized using dimethylformamide as solvent through the phase inversion method. The addition of garlic extract in the manufacture of cellulose acetate membranes had concentrations of 0.25% w/v (0.01 g), 0.5% w/v (0.02 g), 0.75% w/v (0.03 g), and 0% w/v (control) with a thickness of 0.3 mm. The optimum results were obtained for the membrane with a concentration of 0.5% w/v, which resulted in the tensile strength test of 0.977 N/mm2, and the membrane with a concentration of 0.25% w/v, which resulted in an elongation elasticity of 12.22%. The antibacterial properties of membranes with the addition of garlic extract were indicated by the adhesion reduction of Bacillus subtilis bacteria on the membrane surface by 41.5% – 87.7% area.","PeriodicalId":7926,"journal":{"name":"Alchemy: Jurnal Penelitian Kimia","volume":"33 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73110702","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Penambatan Molekul dan Simulasi Dinamika Molekular Kandungan Minyak Kayu Manis dan Minyak Serai Dapur Sebagai Antibakteri Methicillin Resistant Staphylococcus aureus","authors":"Caesart Leonardo Kaharudin, Afif Akmal Afkauni, Aditya Yuan Pramudyansyah, Niko Prasetyo","doi":"10.20961/alchemy.18.2.54997.140-147","DOIUrl":"https://doi.org/10.20961/alchemy.18.2.54997.140-147","url":null,"abstract":"Meluasnya penyebaran Methicillin Resistant Staphylococcus aureus (MRSA) yang kebal terhadap antibiotik β-laktam membuat penelitian untuk menemukan senyawa aktif yang memiliki potensi sebagai antibakteri MRSA menjadi penting. Salah satu penelitian yang dapat dilakukan adalah studi penambatan molekul. Studi penambatan molekul telah dilakukan menggunakan senyawa bahan alam dari minyak kayu manis dan minyak serai dapur dengan reseptor enzim Penicillin Binding Protein 2a (PBP2a). Studi ini memiliki tujuan untuk memprediksi kemampuan senyawa bahan alam dari kedua minyak atsiri tersebut sebagai antibakteri MRSA. Penambatan molekul dilakukan menggunakan perangkat lunak (software) AutoDock 4.2. Hasil penelitian menunjukkan bahwa senyawa dengan potensi sebagai antibakteri paling besar adalah trans-β-kariofilen dan geranil asetat dengan energi ikat sebesar -6,12 dan -5,11 kkal/mol dan konstanta inhibisi sebesar 32,69 dan 180,41 µM. Hasil penambatan molekul kemudian dilanjutkan dengan simulasi dinamika molekular. Hasil simulasi dinamika molekular menunjukkan bahwa kedua senyawa memiliki nilai Root Mean Square Deviation (RMSD) yang tinggi.Molecular Docking and Molecular Dynamics Simulation of Cinnamon Oil and Kitchen Lemongrass Oil as Antibacterial Agent Against Methicillin-Resistant Staphylococcus aureus. The spread of Methicillin-Resistant Staphylococcus aureus (MRSA) caused the research for its antibiotic to become more pressing than ever. One of the research that can be conducted is a molecular docking study. A molecular docking study of natural products from cinnamon and lemongrass oil with Penicillin Binding Protein 2a (PBP2a) enzyme was conducted. This study aims to predict the ability of each natural product to become an MRSA antibiotic. The molecular docking was conducted with AutoDock 4.2 software. The result shows that β-caryophyllene and geranyl acetate have the most potential to become MRSA antibiotics with binding energies of -6.12 kcal/mol and -5.11 kcal/mol and inhibition constants of 32.69 μM and 180.41 µM, respectively. The results of molecular docking were validated using molecular dynamic simulation. Molecular dynamic simulation shows that both complexes have a high root mean square deviation (RMSD) value.","PeriodicalId":7926,"journal":{"name":"Alchemy: Jurnal Penelitian Kimia","volume":"60 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80278964","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pemanfaatan Ekstrak Antosianin dari Limbah Kulit Bawang Merah (Allium cepa) sebagai Zat Pemeka (Sensitizer) pada Dye Sensitized Solar Cell (DSSC)","authors":"R. Adu, G. Gelyaman, Marlince Kabosu","doi":"10.20961/alchemy.18.1.56104.103-111","DOIUrl":"https://doi.org/10.20961/alchemy.18.1.56104.103-111","url":null,"abstract":"Fabrikasi DSSC dengan menggunakan sensitizer zat warna sintetik yang mahal dan susah diperoleh dapat diatasi dengan memanfaatkan zat warna alami dari limbah biomassa kulit bawang merah. Penelitian tentang ekstraksi antosianin dari limbah kulit bawang merah (Allium cepa) dan pemanfaatannya sebagai zat pemeka (sensitizer) pada Dye Sensitized Solar Cell (DSSC) telah dilakukan dengan tujuan untuk mengetahui karakteristik warna ekstrak antosianin dalam limbah kulit bawang merah dan potensinya sebagai zat pemeka dalam DSSC. Antosianin dalam limbah kulit bawang merah diekstraksi dengan menggunakan pelarut etanol 95% dengan penambahan asam (ET) dan etanol tanpa penambahan asam (ETT). Ekstrak kulit bawang merah dikarakterisasi serapan warna dan gugus fungsinya dengan Spektrofotometer UV-Vis pada panjang gelombang 200 nm – 800 nm dan Fourier Transform Infrared (FTIR) pada bilangan gelombang 4000 cm-1 – 500 cm-1. Selanjutnya DSSC difabrikasi dan efisiensi DSSC ditentukan melalui perhitungan tegangan dan kuat arus yang terukur oleh multimeter. Hasil karakterisasi warna menunjukkan bahwa ekstrak kulit bawang merah baik dengan pelarut etanol terasamkan dan tidak terasamkan memiliki serapan maksimum pada panjang gelombang UV dengan serapan utama pada panjang gelombang 221, 251, 291 dan 366 nm. Spektrum FTIR ekstrak kulit bawang menunjukkan serapan khas gugus fungsi pada molekul antosianin pada rentang bilangan gelombang 3418 cm-1– 3375 cm-1 untuk gugus –OH, 2842 cm-1 – 2959 cm-1 untuk C–H alifatik, 1635 cm-1 – 1668 dan 714 cm-1 masing-masing untuk C=C dan C–H aromatic, 1040 cm-1– 1091 cm-1 untuk C–O–C dan 1198 cm-1– 1122 cm-1 untuk C–O alkohol. Hasil pengujian efisiensi sel menunjukkan bahwa sel DSSC yang difabrikasi menggunakan ekstrak etanol TT memiliki nilai efisiensi yang lebih tinggi yaitu sebesar 0,0491%.The Application of Anthocyanins Extracts from Red Onion Peel  Waste (Allium cepa) as a Sensitizer in Dye-Sensitized Solar Cell (DSSC). DSSC fabrication using synthetic dye sensitizers which are expensive and difficult to obtain can be overcome by utilizing natural dyes from onion peel. Anthocyanin extraction from red onion peel (Allium cepa) and its use as a sensitizer in dye-sensitized solar cells (DSSC) has been investigated. The purpose of this study was to determine the color characteristics of anthocyanin extract in onion peel waste and its potential as a sensitizer. Anthocyanin in onion peel waste was extracted using 95% ethanol as a solvent with acid (ET) and ethanol without acid (ETT). The color absorption and functional groups of onion peel extract were characterized using UV-Vis spectrophotometer at 200 nm – 800 nm wavelength and Fourier Transform Infrared (FTIR) at wavenumber of 4000 cm-1 – 500 cm-1. Furthermore, DSSC was fabricated, and an efficiency value was achieved by calculating the voltage and current measured by the multimeter. Onion peel extract has maximum absorption in acidified and unacidified ethanol at UV wavelengths, with the mai","PeriodicalId":7926,"journal":{"name":"Alchemy: Jurnal Penelitian Kimia","volume":"136 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76388107","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modifikasi Sifat Elektronik Material Perovskit NaYTiO4 oleh Variasi Konsentrasi Dopan Lantanum dengan Metode Density Functional Theory","authors":"Wisanggeni Bayu Aji, H. Sutrisno","doi":"10.20961/alchemy.18.1.53333.80-94","DOIUrl":"https://doi.org/10.20961/alchemy.18.1.53333.80-94","url":null,"abstract":"<p>Energi celah pita dan <em>density of state</em> (DOS) dari NaY_(1-x)La_xTiO₄ (x = 0; 0,25; 0,50 dan 0,75) dapat diprediksi secara teoritis menggunakan pendekatan <em>density functional theory</em> (DFT). Perhitungan awal berdasarkan atas pendekatan <em>local density approximation</em> (LDA) dan <em>generalized gradient approximation</em> dari Perdew-Burke-Ernzerhof (GGA+PBE) sebagai fungsional tukar-korelasi. Perhitungan awal energi celah pita dan DOS dilakukan pada unit sel konvensional (1×1×1) untuk NaYTiO₄ dan supersel (2×2×1) untuk NaY_(1-x)La_xTiO₄ (x = 0,25; 0,50 dan 0,75) dengan program CASTEP Materials Studio. Hasil perhitungan menunjukkan energi celah pita (<em>E_g</em>) sebesar 3,447; 3,384; 3,356 dan 3,560 eV untuk x = 0; 0,25; 0,50 dan 0,75 dengan metode LDA. Di sisi lain, metode GGA+PBE menunjukkan <em>E_g </em>sebesar 3,039; 2,963 dan 2,930 eV untuk x = 0; 0,25; 0,50 dan 0,75. Hasil perhitungan karakter DOS menunjukkan bahwa seluruh material menunjukkan transisi <em>E_g </em>tersebut dikontribusi oleh transisi elektron antara pita valensi O 2<em>p</em> dan konduksi Ti 3<em>d</em><em>. </em>Susbtitusi atom La pada posisi atom Y tidak menghasilkan pita di tengah <em>E_g</em> (<em>intermediate band</em>) melainkan hanya memperlebar atau mempersempit celah pita pada NaY_(1-x)La_xTiO₄ akibat distorsi panjang ikatan Ti‒O. Penelitian ini menunjukkan peran signifikan dari La terhadap sifat elektronik material NaY_(1-x)La_xTiO₄ untuk aplikasi pada sel surya di masa depan. </p><p><strong>Modification of Electronic Properties of NaYTiO₄ Perovskite Material by Variation of Lanthanum Dopants Concentration using Density Functional Theory Method. </strong>Bandgap energy and density of state (DOS) of NaY_(1-x)La_xTiO₄ (x = 0; 0.25; 0.50 and 0.75) can be predicted theoretically using density functional theory (DFT) approach. The initial calculation is based on the local density approximation (LDA) and generalized gradient approximation of Perdew-Burke-Ernzerhof (GGA+PBE) as exchange-correlation functional. Initial calculations of bandgap energy and DOS were performed on conventional unit cells (1×1×1) for NaYTiO₄ and supercells (2×2×1) for NaY_(1-x)La_xTiO₄ (x = 0.25; 0.50 and 0.75) with the CASTEP Materials Studio program. The calculation results show the bandgap energy (<em>E_g</em>) of 3.447; 3.384; 3.356 and 3.560 eV for x = 0; 0.25; 0.50 and 0.75 with the LDA method. On the other hand, the GGA+PBE method shows an <em>E_g</em> of 3.039; 2.963 and 2.930 eV for x = 0; 0.25; 0.50 and 0.75. DOS character calculation results show that all materials exhibit the <em>E_g</em> transition, which is contributed by the electron transition between the O 2<em>p</em> valenc","PeriodicalId":7926,"journal":{"name":"Alchemy: Jurnal Penelitian Kimia","volume":"23 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84835983","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Kinetika Esterifikasi Asam Lemak Bebas dari Sludge Industri Crude Palm Oil (CPO) Menggunakan Katalis Komposit Montmorillonite/Karbon Tersulfonasi dari Tetes Tebu","authors":"Qodria Utami Putri, Diah Augustin, Hasanudin Hasanudin","doi":"10.20961/alchemy.18.1.50470.48-57","DOIUrl":"https://doi.org/10.20961/alchemy.18.1.50470.48-57","url":null,"abstract":"Kinetika esterifikasi asam lemak bebas dari sludge CPO telah dilakukan dengan pereaksi etanol dan menggunakan katalis komposit montmorillonite/karbon tersulfonasi dari tetes tebu. Esterifikasi dilakukan dengan memvariasikan temperatur (60, 70, dan 80 oC) dan rasio mol antara etanol dan asam lemak bebas (10, 13, 16, 19, dan 22). Hasil penelitian menunjukan bahwa semakin tinggi temperatur, akan meningkatkan laju reaksi esterifikasi, konstanta laju reaksi dan konstanta kesetimbangan reaksi esterifikasi asam lemak bebas. Hal ini menunjukan bahwa reaksi esterifikasi merupakan reaksi endoterm. Sementara itu, semakin besar rasio mol antara etanol dan asam lemak bebas, akan menurunkan laju reaksi. Konstanta Arrhenius dari reaksi esterifikasi tersebut adalah sebesar 2,7183 dan energi aktivasi sebesar 17,9366 kJ/mol. Hasil uji validasi persamaan model kinetika menggunakan nilai R2 dan slope dari grafik perbandingan antara nilai x hasil eksperimen dan x hitung model kinetika. Nilai R2 dan slope dari grafik mendekati angka 1 yang menunjukkan bahwa model persamaan yang digunakan dapat diterima dan layak untuk menghitung kinetika esterifikasi asam lemak bebas.Kinetics of Esterification of Free Fatty Acids from Crude Palm Oil (CPO) Industrial Sludge Using a Montmorillonite/Sulfonated Carbon Composite Catalyst from Molasses. Kinetics of esterification of free fatty acids from crude palm oil sludge esterification has been carried out with reagent ethanol and using the composite catalyst of montmorillonite/ sulfonated carbon from molasses. Esterification was done by varying the temperature (60, 70, and 80 °C) and the mole ratio between ethanol and free fatty acids (10, 13, 16, 19, and 22). The results showed that the higher temperature would increase the rate of esterification reaction, the reaction rate constants, and the equilibrium constants esterification of free fatty acids. These findings show that the esterification reaction is an endothermic reaction. Meanwhile, the larger mole ratio between ethanol and free fatty acids would decrease the reaction rate. Arrhenius’s constant value of the esterification reaction is 2.7183 and the activation energy is 17.9366 kJ/mol. The results of the validation test of the kinetic model equation using the value of R2 and the slope of the comparison graph between the x value of the experimental results and the calculated x of the kinetic model. The value of R2 and the slope of the graph is close to 1 which indicates that the equation model used is acceptable and feasible to calculate the kinetics of free fatty acid esterification. ","PeriodicalId":7926,"journal":{"name":"Alchemy: Jurnal Penelitian Kimia","volume":"98 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77492887","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sintesis Kitosan dari Kulit Udang sebagai Bahan Membran Elektrode Au/Kitosan/GTA/AChE untuk Deteksi Pestisida","authors":"Mashuni Mashuni, Halimahtussaddiyah Ritonga, M. Jahiding, Fitrianita Hamid","doi":"10.20961/alchemy.18.1.56551.112-121","DOIUrl":"https://doi.org/10.20961/alchemy.18.1.56551.112-121","url":null,"abstract":"Sintesis kitosan telah dikembangkan dengan metode pemanasan microwave (MW) menggunakan pelarut alkali untuk kebutuhan berbagai aplikasi yang salah satunya sebagai membran immobilisasi enzim. Penelitian membran kitosan dengan immobilisasi enzim asetilkolinesterase (AChE) sebagai elektrode biosensor terus berkembang untuk menghasilkan perangkat mutakhir yang dapat mendeteksi pestisida. Penelitian ini bertujuan untuk menghasilkan biosensor berbasis elektrode membran Au/Kitosan/GTA/AChE untuk deteksi pestisida karbaril yang memiliki batas deteksi yang rendah, sensitivitas yang tinggi, waktu respon cepat dan presisi yang baik. Kitosan dihasilkan dari isolasi kitin dari kulit udang menggunakan alat MW dan pelarut NaOH dengan daya 450 Watt selama 15 menit menghasilkan rendemen sebesar 31,50%. Karakterisasi FTIR kitosan diidentifikasi adanya gugus O–H, C–N, N–H amina, dan C=O dengan intensitas yang rendah serta derajat deasetilasi rata-rata 95,6 ± 0,1%. Komposisi elektrode membran Au/Kitosan/GTA/AChE menggunakan kitosan dengan variasi konsentrasi 2, 5, dan 8% (b/v) dan glutaraldehid (GTA) 25%, kawat Au dan diimobilisasikan enzim asetilkolinesterase (AChE). Elektrode membran Au/Kitosan 2%/GTA/AChE memiliki karakteristik yang baik dimana nilai sensitivitas sebesar 23,318 mV.dekade-1 pada rentang konsentrasi pestisida 10-7 – 10-1 µg mL-1 dengan batas deteksi (LoD) 1 × 10-7 µg mL-1. Waktu respon yang diperoleh yaitu pada rentang waktu 5– 7 menit dengan relative standard deviation (RSD) sebesar 0,588%. Biosensor yang dikembangkan menunjukkan sensitivitas, stabilitas dan reproduktifitas yang baik, sehingga elektrode membran Au/Kitosan/GTA/AChE menjanjikan untuk alat deteksi pestisida. Synthesis of Chitosan from Shrimp Shell as Electrode Membrane Material Au/Chitosan/GTA/AChE for Pesticide Detection. Chitosan synthesis has been developed using the heating by microwave (MW) method using alkaline solvents for various applications, one of which is an enzyme immobilization membrane. Chitosan membrane research with immobilization of the enzyme Acetylcholinesterase (AChE) as a biosensor electrode developed to produce advanced devices that can detect pesticides. This study aims to produce a biosensor based on Au/Chitosan/GTA/AChE membrane electrodes to detect carbaryl pesticides with a low detection limit, high sensitivity, fast response time, and good precision. Chitosan was produced from the isolation of chitin from shrimp shells using an MW device and NaOH solvent with a power of 450 Watts for 15 minutes to produce a yield of 31.50%. The FTIR characterization of chitosan identified the presence of O–H, C–H, C–N, N–H amine groups and C=O with low intensity and the average degree of deacetylation of 95.6 ± 0.1%. The composition of Au/Chitosan/GTA/AChE membrane electrodes used chitosan with various concentrations of 2, 5, and 8% (w/v) and glutaraldehyde (GTA) 25% on Au wire and immobilized with AChE enzyme. The Au/Chitosan 2%/GTA/AChE membrane electrode has good chara","PeriodicalId":7926,"journal":{"name":"Alchemy: Jurnal Penelitian Kimia","volume":"26 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89937247","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sintesis dan Karakterisasi Komposit Eugenol-Silika Gel dari Abu Tongkol Jagung serta Analisis Antibakteri dan Daya Serap terhadap Air","authors":"Muhammad Jundi Fathurrahman, Usep Suhendar, A. Iryani, Diana Widiastuti, Sherin Nurhafidza Ahmad, Esya Juniar","doi":"10.20961/alchemy.18.1.47161.10-18","DOIUrl":"https://doi.org/10.20961/alchemy.18.1.47161.10-18","url":null,"abstract":"Tongkol jagung mempunyai kandungan silika yang cukup tinggi, yaitu 67,41% dari total abunya yang memungkinkan untuk dimanfaatkan untuk pembuatan komposit eugenol-silika gel. Penelitian ini bertujuan mempelajari pembuatan komposit eugenol-silika gel dengan bahan dasar abu tongkol jagung menggunakan metode sol gel, diikuti dengan analisis daya serap air dan aktivitas antibakteri terhadap E. coli dan S. aureus. Komposit eugenol-silika gel ini dikarakterisasi menggunakan Fourier Transform Infrared (FTIR), X-ray Diffraction (XRD), Scanning Electron Microscope (SEM) dan Thermogravimetric Analysis (TGA). Hasil karakterisasi dengan FTIR menunjukkan bahwa sintesis komposit eugenol-silika gel berhasil dilakukan. Analisis menggunakan XRD menunjukkan bahwa komposit eugenol-silika gel memiliki bentuk amorf. Karakteristik mikrostruktur menggunakan SEM menunjukkan permukaan yang tidak merata dan terdapat gumpalan (cluster) yang menandakan adanya bentuk butiran-butiran yang beragam berbentuk bulat atau globular pada permukaan komposit eugenol-silika gel. Analisis termogravimetri yang dilakukan sampai suhu 600 °C menunjukkan total prosentase pengurangan massa komposit eugenol silika-gel sebesar 13,10%. Daya serap air komposit eugenol-silika gel memiliki nilai persentase yang lebih tinggi dibandingkan dengan silika gel food grade. Akan tetapi, komposit eugenol-silika gel tidak memiliki aktivitas antibakteri terhadap E. coli dan S. aureus.Synthesis and Characterization of Eugenol-Silica Gel Composite from Corn Cob Ash and Analysis of Antibacterial and Water Absorption. Corn cobs have high silica content, specifically 67.41% of the total ash, possibly used for eugenol-silica gel composite manufacture. This study aims to synthesize eugenol-silica gel composite with corn cob ash as the base material by sol gel method, followed by analyzing water absorption and antibacterial activity against E. coli and S. aureus. The method used is the sol-gel method. This eugenol-silica gel composite was characterized using Fourier Transform Infrared (FTIR), X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), and Thermogravimetric Analysis (TGA). The characterization results by FTIR showed that the synthesis of the eugenol-silica gel composite was successfully carried out. Analysis using XRD showed that the eugenol-silica gel composite had an amorphous form. Microstructural characteristics using SEM showed an uneven surface and clusters indicating the presence of various globular or spherical shapes on the surface of the eugenol-silica gel composite. Thermogravimetric analysis carried out until a temperature of 600 °C showed the total percentage reduction in mass of the eugenol silica-gel composite was 13.10%. The water absorption of eugenol-silica gel composite has a higher percentage value than food-grade silica gel. However, eugenol-silica gel composite has no antibacterial activity against E. coli and S. aureus. ","PeriodicalId":7926,"journal":{"name":"Alchemy: Jurnal Penelitian Kimia","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89156312","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pelapisan Komposit TiO2-SiO2 pada Kain Poliester dengan Metode Dip Coating pada Pembuatan Masker Hidrofobik Antivirus","authors":"Rifky Adhia Pratama, Yuni Nurhayati, Dea Fauziah Fitri, Ahlam Nauval Mahendra, Kiagus Ahmad Mirza Azuri, Diana Rakhmawaty Eddy","doi":"10.20961/alchemy.18.1.55003.95-102","DOIUrl":"https://doi.org/10.20961/alchemy.18.1.55003.95-102","url":null,"abstract":"<p><span><span lang=\"EN-US\">P</span><span>enelusuran potensi komposit TiO₂-SiO₂ (sumber silika dari abu sekam padi) sebagai material <em>coating</em> untuk pembuatan masker kain yang hidrofobik dan memiliki sifat antivirus merupakan tujuan utama dalam penelitian ini. Metode yang digunakan untuk sintesis komposit TiO₂-SiO₂ adalah metode sol-gel. Adapun proses <em>coating</em> dilakukan dengan metode <em>dip coating</em>. Hasil karakterisasi PSA menyatakan bahwa rata-rata ukuran partikel silika dari abu sekam padi yang terbentuk adalah 202,98 nm. Tipe kristal komposit TiO₂-SiO₂ yang terkonfirmasi XRD adalah campuran fase anatase dan <em>brookite</em>. Hasil SEM memperlihatkan bahwa komposit yang telah disintesis menempel kuat di serat-serat kain, yang mengindikasikan bahwa proses <em>coating</em><em> </em>berjalan sempurna. Hasil pengujian sudut kontak menunjukkan bahwa kain hasil <em>coating</em> bersifat hidrofobik karena memiliki nilai sudut 110,4°</span><span lang=\"EN-US\">. Suhu permukaan kain hasil <em>coating</em><em> </em>yang dikarakterisasi dengan <em>thermal camera</em> menunjukkan hasil yang baik karena hanya dalam kurun waktu 10 menit iradiasi sinar UV-C, suhu permukaannya sudah melebihi </span><span>40 °C. Oleh karena itu, kain hasil <em>coating</em> memiliki potensi besar untuk diaplikasikan menjadi masker antivirus karena <em>receptor binding</em> motif dari protein <em>spike</em> SARS-CoV-2 mulai mengalami penutupan konformasi pada suhu 40 °C. </span> </span></p><p><strong>TiO₂-SiO₂ Composite Coating on Polyester Fabrics using Dip Coating Method for Antivirus Hydrophobic Mask Fabrication. </strong>Exploring the potential of TiO₂-SiO₂ composite (a silica source obtained from rice husk ash) as a <em>coating</em> material for the manufacture of hydrophobic and antiviral fabric masks is the main goal of this study. The sol-gel method is used in the manufacture of TiO₂-SiO₂ composites. The coating process is carried out using a dip coating method. The results of PSA characterization show that the average silica particle size formed was 202.98 nm. The XRD confirmed that the TiO₂-SiO₂ composite crystal type is a mixture of anatase and brookite phases. The SEM shows that that the synthesized composite adheres strongly to the fabric fibers, indicating that the coating process runs perfectly because it is clearly seen. The results of the contact angle test show that the coated fabric is hydrophobic because it has an angle value of 110.4°. The surface temperature of the coated fabric characterized by a thermal camera shows good results because in just 10 minutes of UV-C irradiation, the surface temperature has exceeded 40 °C. Therefore, the coated fabric has a great potential to be applied as an antiviral mask because the receptor binding motif of the SARS-CoV-2 spike protein begins to underg","PeriodicalId":7926,"journal":{"name":"Alchemy: Jurnal Penelitian Kimia","volume":"20 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79963724","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Biosensor DNA Elektrokimia untuk Deteksi Makanan Mengandung Babi (Sus scrofa) Menggunakan Screen Printed Carbon Electrode Termodifikasi Emas","authors":"Shabarni Gaffar, Annisa Ilma Naviardianti, Santhy Wyantuti, Y. Hartati","doi":"10.20961/alchemy.18.1.50170.37-47","DOIUrl":"https://doi.org/10.20961/alchemy.18.1.50170.37-47","url":null,"abstract":"Metode deteksi berbasis deoxyribonucleic acid (DNA) merupakan metode yang paling akurat, spesifik, dan sensitif untuk mengidentifikasi adanya campuran komponen babi dalam produk pangan. Penelitian ini bertujuan untuk mengembangkan biosensor DNA secara elektrokimia menggunakan Screen Printed Carbon Elektrode termodifikasi emas (SPCE-Au) untuk mendeteksi DNA babi dalam makanan olahan. Permukaan SPCE dimodifikasi dengan emas menggunakan metode adsorbsi pasif, kemudian dikarakterisasi dengan Scanning Electron Microscopy (SEM) dan Differential Pulse Voltammetry (DPV). DNA probe yang spesifik terhadap DNA mitokondria babi diimobilisasi ke permukaan SPCE-Au melalui perantara gugus tiol. Proses hibridisasi DNA probe-DNA komplemen dikarakterisasi menggunakan DPV berdasarkan sinyal oksidasi guanin. Kondisi percobaan dioptimasi menggunakan desain eksperimen Box-Behnken, yaitu konsentrasi DNA probe (0,5; 1,0; 1,5 µg/mL), waktu imobilisasi DNA probe (10, 20, 30 menit), dan waktu hibridisasi DNA probe-DNA komplemen (5, 10, 15 menit). Kondisi optimum digunakan untuk menentukan respons arus oksidasi guanin menggunakan DPV terhadap variasi konsentrasi DNA komplemen. Selanjutnya, biosensor DNA diaplikasikan terhadap sampel bakso yang mengandung campuran daging babi, ayam, dan sapi. Hasil penelitian menunjukkan modifikasi SPCE dengan Au menghasilkan peningkatan arus yang diuji menggunakan sistem redoks K3[Fe(CN)6] secara DPV. Kondisi optimum percobaan adalah: konsentrasi DNA probe 1 µg/mL, waktu imobilisasi DNA probe 20 menit, dan waktu hibridisasi DNA probe-DNA komplemen 10 menit. Biosensor DNA ini memiliki batas deteksi 0,31 µg/mL, batas kuantifikasi 1,06 µg/mL dan recovery 99,2% untuk rentang konsentrasi 0,1 - 2 µg/mL. Deteksi sampel bakso menggunakan biosensor DNA menunjukkan peningkatan respons arus yang signifikan pada sampel yang mengandung 100% daging babi (3,417 µA) dan masih dapat mendeteksi adanya kandungan daging babi sampai 1%. Metoda biosensor DNA babi menggunakan SPCE-Au tanpa indikator dan biokonjugat yang dikembangkan lebih sederhana dan cepat dan mudah untuk diaplikasikan ke sampel nyata. Electrochemical DNA Biosensor for Detection of Pork (Sus scrofa) Using Gold Modified Screen Printed Carbon Electrode. The DNA-based detection method is the most accurate, specific, and sensitive method for identifying the presence of a mixture of pork components in food products. This study aims to develop an electrochemical DNA biosensor using a gold-modified Screen Printed Carbon Electrode (SPCE-Au) to detect pork DNA in processed food. The surface of the SPCE was modified with gold using a passive adsorption method, then characterized by scanning electron microscopy (SEM) and differential pulse voltammetry (DPV). The probe DNA specific to porcine mitochondrial DNA was immobilized to SPCE-Au surface via an intermediate thiol group. The hybridization of probe DNA-complement DNA was characterized using DPV based on the guanine oxidation signal. The experimental c","PeriodicalId":7926,"journal":{"name":"Alchemy: Jurnal Penelitian Kimia","volume":"26 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82871188","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}