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ALCHEMY Jurnal Penelitian Kimia
Published by Universitas Sebelas Maret
ISSN : 14124092     EISSN : 24434183     DOI : -
Core Subject : Science, Social, Engineering,
Chemical Engineering, Chemistry & Bioengineering Chemistry Energy Environmental Science Materials Science & Nanotechnology
ALCHEMY Jurnal Penelitian Kimia is a chemistry journal published by Sebelas Maret University, Surakarta. ALCHEMY Jurnal Penelitian Kimia publishes original research articles or review articles in organic chemistry, inorganic chemistry, analytical chemistry, physical chemistry, biochemistry, and environmental chemistry.
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Articles 11 Documents
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Search results for , issue "Vol 20, No 2 (2024): September" : 11 Documents clear
Enhancement of Liberica Coffee Quality by Wet Fermentation using Bacillus subtilis Indra Lasmana Tarigan; Ericha Aulia; Heriyanti Heriyanti; Madyawati Latief; Sutrisno Sutrisno
ALCHEMY Jurnal Penelitian Kimia Vol 20, No 2 (2024): September
Publisher : UNIVERSITAS SEBELAS MARET (UNS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/alchemy.20.2.74248.162-177

Abstract

Coffee is a tree species in the Rubiaceae family and Coffea genus. One way to enhance the value of coffee commodities is by using fermentation technology. Fermentation can use probiotic bacteria found in mongoose digestive tracts, creating coffee with a unique taste and aroma. Bacillus subtilis is one of these bacteria, offering an alternative to those from mongoose. This study aimed to analyze the effects of fermentation using B. subtilis bacteria on the physicochemical and sensory properties of Liberica coffee. The study method included bacteria preparation, coffee fermentation, and testing. The samples' total phenolics, flavonoids, caffeine, and chlorogenic acid contents were estimated. The analysis was performed using UV-Vis and GC-MS spectrophotometers. The results revealed that the fermentation process using B. subtilis improved the sensory and physical qualities of the fermented Liberica coffee. The total values of phenolic and flavonoid contents and antioxidants of the fermented Liberica coffee were higher than that of the original coffee. GC-MS analysis exhibited compounds in the fermented coffee in which the highest was N-Dodecyl-N-(trifluoroacetyl)dodecanamide (C26H48F3NO2), with a retention time of 23.73 minutes and an area percentage of 18.96%. Moreover, the caffeine and chlorogenic acid of the fermented Liberica coffee was lower than that of the original coffee.
Microwave-Assisted Synthesis of Corn Husk-Based Hydrogels Grafted with Acrylamide Ginanjar Penata Aji; Mahira Noor Syevarani Arifandi; Sperisa Distantina; Mujtahid Kaavessina
ALCHEMY Jurnal Penelitian Kimia Vol 20, No 2 (2024): September
Publisher : UNIVERSITAS SEBELAS MARET (UNS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/alchemy.20.2.79274.198-205

Abstract

Corn husk waste contains cellulose, which has the potential as a raw material for hydrogel preparation. Hydrogels can be applied as water purification, diapers, and superabsorbents. This study aimed to synthesize hydrogel from corn husk cellulose grafted with acrylamide monomer using a microwave-assisted grafting method. Potassium peroxodisulfate (PPD) was used as an initiator, and the effects of acrylamide and PPD on hydrogel swelling capacity were investigated. The process involved drying and crushing corn husks into powder, then mixing the powder with acrylamide and PPD for microwave grafting to form a polymer, which was then ground into powder. The grafted polymer was combined with carrageenan to create bead gels soaked in distilled water and urea to measure swelling capacity. Results showed that swelling capacity increased with more acrylamide and decreased with more PPD. The highest swelling capacity reached 1016.16% in water and 961.6% in urea. FTIR analysis confirmed the successful grafting of acrylamide onto corn husk cellulose by detecting changes in the infrared spectrum. Based on FTIR and swelling capacity data, it was concluded that the grafting process was completed using the microwave method with PPD as the initiator.
Performance Improvement Polyvinylidene Fluoride (PVDF) Mordenite Membranes for Oil-in-Water Emulsion Separation Brigitta Elga Kusuma Dewi; Pranoto Pranoto; Ozi Adi Saputra; Edi Pramono
ALCHEMY Jurnal Penelitian Kimia Vol 20, No 2 (2024): September
Publisher : UNIVERSITAS SEBELAS MARET (UNS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/alchemy.20.2.82146.226-237

Abstract

Improving the performance of membranes appropriate for oil-in-water separation is a global challenge. In this study, we prepared a PVDF/Mordenite (PZM) membrane and determined its properties to separate oil-in-water emulsions to address this challenge. The PVDF and PZM membranes were fabricated using the phase inversion technique and applied to separate two types of oil-in-water emulsions 1:99 (wt%), including vegetable oil and used cooking oil emulsion. PVDF polymer with DMAc solvent was added to mordenite with a concentration variation of mordenite. The addition of mordenite did not affect the increase of the β fraction on the hybrid membrane surface but could improve the membrane hydrophilicity. The addition of mordenite in the PVDF membrane has improved the characteristics of the membrane, including water flux, rejection membrane >90%, and FRR up to two times greater than a pristine PVDF membrane. Morphological analysis of the membrane confirmed an asymmetric membrane composed of finger-like and sponge-like. Combining mordenite and PVDF membrane to separate oil-in-water emulsions provides a new approach to oil wastewater treatment.
Screen-printed Carbon Electrode from Coconut Shell Activated Carbon Modified with Ferrocene for Cobalt Detection Muhammad Farhan; Eddy Heraldy; Abu Masykur; Muhammad A. Munir; Fitria Rahmawati
ALCHEMY Jurnal Penelitian Kimia Vol 20, No 2 (2024): September
Publisher : UNIVERSITAS SEBELAS MARET (UNS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/alchemy.20.2.81386.247-256

Abstract

This research aims to fabricate a screen-printed carbon electrode (SPCE) from coconut shell charcoal. The charcoal was activated with NaOH to produce activated carbon (Ac). It was mixed with acetylene black (AB) and poly (vinylidene) Fluoride (PVDF) at the mass ratio of 7:2:1 for the Ac, AB, and PVDF, respectively, followed by a dispersing with N-Methyl-2-Pyrrolidinone (NMP) producing carbon slurry that was painted on a SPCE template. To increase electrochemical sensitivity, ferrocene, Fc was dropped onto the working electrode part at 10%, 20%, and 30% of the total SPCE mass. The results show that Ac is amorphous with a porous chip-like morphology containing 61.7% carbon. Ac shows vibrations of O–H, C=O, C=C, C–O, and Si–O with surface area and average pore size of 154.612 m2 g-1 and 1.42 nm, respectively. The cyclic voltammetry analysis found that 10% Fc on SPCE provides the highest current density compared to 20% and 30%. Meanwhile, the 2 mV s-1 scanning rate reveals a more defined anodic and cathodic peak than 3 mV s-1 and 5 mV s‑1. Furthermore, the SPCE with 10% Fc shows a good sensitivity to Co (II) ions, proven by a low detection limit (LoD) of 0.224 mmol L-1
Sintesis Hidroksiapatit secara Elektrolisis sebagai Bahan Baku Pembuatan Scaffold Tissue HA/PVA-AgCl untuk Aplikasi Penyembuhan Luka Supriyono Supriyono; Bambang Poerwadi; Denny Widhiyanuriyawan; Nasirotul Wildah; Mahfita Ardyarum; Nabila Widadudari; Ilhan Junio Trizardi; Ulya Ahda Yustisia
ALCHEMY Jurnal Penelitian Kimia Vol 20, No 2 (2024): September
Publisher : UNIVERSITAS SEBELAS MARET (UNS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/alchemy.20.2.80273.206-217

Abstract

Hidroksiapatit (HA) sebagai bahan dasar dalam scaffold tissue memiliki kemampuan untuk berikatan langsung dengan jaringan tubuh secara in vivo. Scaffold tissue pada penelitian ini dalam bentuk membran komposit terdiri dari nHA/PVA-AgCl. AgCl berfungsi sebagai agen antibakteri, sedangkan PVA berfungsi sebagai polimer perekat. Ukuran nanometer untuk HA diperoleh melalui proses elektrolisis yang mengatur voltase untuk mengendalikan ukuran partikel. Variasi potensial listrik elektrolisis 4, 5, dan 6 V digunakan dalam proses selama enam jam. Sebagai pembanding, HA komersil juga digunakan dalam penelitian ini dan hasilnya menunjukkan bahwa voltase 5 V menghasilkan HA yang murni tanpa adanya brushite. Dalam hal diameter partikel, HA yang disintesis dengan potensial listrik 4, 5, dan 6 V, serta HA komersil masing-masing memiliki diameter 232 nm, 276 nm, 355 nm, dan 5421 nm. Metode BET untuk pengujian luas permukaan menghasilkan nilai berturut-turut untuk variabel potensial listrik elektrolisis HA 4, 5, dan 6 V, serta HA komersil masing-masing adalah 317,22; 344,247; 323,419; dan 205,779 m2/g. Hasil uji pre-klinis selama tujuh hari menunjukkan bahwa scaffold tissue yang menggunakan HA sintesis dengan voltase 5 V menghasilkan pertumbuhan fibroblas yang paling baik, dengan nilai rata-rata sekitar 47,3±4,53 fibroblas/nm2.Synthesis of Hydroxyapatite by Electrolysis as Raw Material for Making HA/PVA-AgCl Tissue Scaffold for Wound Healing Application. . Hydroxyapatite (HA), the primary material in scaffold tissue, can directly interact with the body's tissues in vivo. In this research, the scaffold tissue forms a composite membrane consisting of nHA/PVA-AgCl, with AgCl as an antibacterial agent and PVA as a binding polymer.Nanometer-sized HA particles are obtained through electro-synthesis, controlling voltage to regulate particle size. Three voltage variations, 4, 5, and 6 Vare used in the process for 6 hours. Commercial HA is also used for comparison, and the results indicate that 5 V voltage produces pure HA without brushite contamination. In terms of particle diameter, HA synthesized at 4, 5, 6 V, and commercial HA each have diameters of 232, 276, 355, and 5421 nm, respectively. The BET method is employed to test surface area, yielding consecutive values for the electro-synthesized HA voltage variations, with 4, 5, 6 V, and commercial HA having surface areas of 317.22; 344.247; 323.419; and 205.779 m2/g, respectively. The pre-clinical test in 7-days period findings reveal that scaffold tissue using HA synthesized at 5V voltage produces the best fibroblast growth, with an average value of approximately 47.3±4.53 fibroblasts/nm2.
Trace Detection of Pb(II) using Square Wave Anodic Stripping Voltammetry with Stainless Steel Electrodes Sendika Harrista; Muhammad Zamhari; Adinda Fara Aulia; Safina Nur Faizah; Tawatchai Kangkamano
ALCHEMY Jurnal Penelitian Kimia Vol 20, No 2 (2024): September
Publisher : UNIVERSITAS SEBELAS MARET (UNS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/alchemy.20.2.84859.238-246

Abstract

Lead (Pb(II)) is well known as a dangerous environmental contaminant that harms public health worldwide. Early Pb(II) detection before release into the water system is important. This work describes an inexpensive Pb(II) determination using 5 mm diameter stainless steel rod type 304 as a working electrode. Using a batch system, the research employed 10 mL of 0.1 M acetate buffer at pH 4.5. The best operation was at a deposition potential of -1.2V for 300 s. It provides a linear range in the concentration range of 0.075 – 1 µg/mL Pb(II) (r = 0.994). The limit of detection (LOD) and limit of quantification (LOQ) of Pb(II) were at 0.057 µg/mL and 0.189 µg/mL, respectively. Repeatability and reproducibility were expressed in the relative standard deviation range of 1.26-3.71% in the testing a Pb(II) concentration range of 0.2-1.0 µg/mL and 5.32% in testing a Pb(II) concentration of 0.4 µg/mL. A very low-cost stainless-steel electrode proposed a high operational stability up to 10 measurements with RSD of 4.39%.
Optimasi Sifat Mekanik Komposit Bioplastik dari Selulosa Ampas Sagu dan Kitosan Cangkang Kepiting Halimahtussaddiyah Ritonga; Mashuni Mashuni; Wa Hardima
ALCHEMY Jurnal Penelitian Kimia Vol 20, No 2 (2024): September
Publisher : UNIVERSITAS SEBELAS MARET (UNS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/alchemy.20.2.85193.190-197

Abstract

Studi awal perlu dilakukan dalam mempelajari sifat mekanik komposit suatu bioplastik. Hal ini dilakukan agar diperoleh bioplastik yang dapat disesuaikan dengan pemanfaatanya secara tepat. Kemampuan terdegradasinya juga perlu dipelajari agar pemanfaatannya tidak merusak lingkungan. Penelitian untuk mengetahui pengaruh komposisi selulosa-kitosan terhadap sifat mekanik bioplastik, morfologi dan sifat biodegradabilitas. Pada penelitian ini bioplastik berbahan dasar limbah ampas sagu. Kitosan diperoleh dari isolasi limbah cangkang kepiting menggunakan metode microwave. Pembuatan bioplastik menggunakan metode blending dengan variasi perbandingan selulosa-kitosan 3:1, 4:1, dan 5:1 (b/b). Analisis Fourier Transform Infrared (FTIR) menunjukkan adanya gugus OH, CH, dan NH pada film. Hasil Scanning Electron Microscope (SEM) menunjukkan permukaan yang tidak rata dan adanya aglomerasi.  Uji ketahanan air yang diperoleh berturut turut 131; 110,5; dan 92,68%. Bioplastik dengan daya serap air paling rendah terdapat pada variasi 5:1 yaitu sebesar 92,68%. Uji sifat mekanik menunjukkan penambahan berat selulosa dapat meningkatkan nilai kuat tarik dan modulus young, tetapi menurunkan nilai elongasi. Nilai kuat tarik terbaik terdapat pada perbandingan selulosa-kitosan 5:1 sebesar 1,48 MPa. Nilai elongasi terbaik terdapat pada komposisi 4:1 sebesar 13,36% dan nilai modulus young terbaik terdapat pada komposisi 5:1 sebesar 12,62 MPa.  Uji biodegradabilitas menunjukkan persentase pengurangan bioplastik terbesar setelah 28 hari penguburan yaitu 85% (3:1). Optimization of Mechanical Properties of Bioplastic Composite from Sago Pulp Cellulose and Crab Shell Chitosan. Preliminary studies are necessary to study the mechanical properties of bioplastic to obtain bioplastics that can be adjusted to their proper use. The degradable ability also needs to be examined so that its utilization does not damage the environment. This study investigated how cellulose and chitosan composition affects these bioplastics' mechanical, morphological, and biodegradable properties. Cellulose-based bioplastics were isolated from sago pulp waste, while chitosan was extracted from crab shell waste using the microwave method. The bioplastics were produced through a blending process with different cellulose-chitosan ratios of 3:1, 4:1, and 5:1 (w/w). FTIR analysis revealed the presence of OH, CH, and NH groups in the bioplastic film. SEM results showed an uneven surface and agglomeration in the bioplastic. Water resistance tests yielded 131, 110.5, and 92.68% absorption capacities for the respective ratios, with the lowest absorption seen in the 5:1 variation. Mechanical tests demonstrated that increasing cellulose content improved tensile strength and Young's modulus but reduced elongation. The highest tensile strength (1.48 MPa) was achieved with a 5:1 cellulose-chitosan ratio. The best elongation (13.36%) was observed in the 4:1 composition, and the highest Young's modulus (12.62 MPa) was found in the 5:1 composition. The biodegradability test showed the most significant percentage of bioplastic reduction after 28 days of burial, which was 85% (3:1).
Studi Bioakumulasi Ion Logam Pb(II) oleh Tumbuhan Mangrove (Sonneratia alba) di Perairan Desa Passo Kota Ambon Abraham Mariwy; Sunarti Sunarti; Cynthia T Tewernussa
ALCHEMY Jurnal Penelitian Kimia Vol 20, No 2 (2024): September
Publisher : UNIVERSITAS SEBELAS MARET (UNS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/alchemy.20.2.74274.267-277

Abstract

ABSTRAK. Jenis partikel dan kandungan Pb pada sedimen, akar dan daun, adalah variabel penting untuk mempelajari akumulasi ion logam Pb(II) oleh tumbuhan mangrove pada perairan Desa Passo Kota Ambon. Jenis partikel sedimen dianalisis menggunakan sieve shaker. Kandungan logam timbal (Pb) pada sedimen, akar dan daun mangrove diukur menggunakan spektrofotometer serapan atom. Kemampuan akumulasi dan translokasi timbal (Pb) pada tumbuhan mangrove (Sonneratia alba) diketahui dari nilai BCF (bioconcentration factor) dan TF (translocation factor). Hasil penelitian menunjukkan bahwa jenis partikel pada stasiun I untuk graval 33,55%, pasir 63,38%, dan lumpur 0,98%, pada stasiun II graval 28,41%, pasir 70,06%, dan lumpur 3,01%, dan stasiun III untuk graval 49,69%, pasir 51,24%, dan lumpur 2,83%. Kandungan logam  timbal (Pb) pada sedimen, akar dan daun di stasiun I secara berturut-turut adalah 41,53; 7,04; dan 2,52 mg/kg; pada stasiun II secara berturut-turut sebesar 44,34; 1,12; dan 3,12 mg/kg; sedangkan pada stasiun III sebesar 43,19; 15,37; dan 20,31 mg/kg. Nilai BCF yang diperoleh pada stasiun I, II, dan III secara berturut-turut yakni 0,22; 0,09; 0,82. Nilai TF pada stasiun I, II, dan III berturut-turut adalah 0,35, 2,78, 1,32. ABSTRACT. (Pb(II) Metal Ions Bioaccumulation Study by Mangrove Plants (Sonneratia alba) in Passo Village Waters Ambon City). Particle types and Pb content in sediments, roots, and leaves are important variables in studying the accumulation of Pb metal by mangrove plants in Passo Village Ambon City waters. Sediment particles were analyzed using a sieve shaker. The content of lead metal (Pb) in sediments, roots, and leaves of mangroves was measured using an atomic absorption spectrophotometer. The ability of lead (Pb) accumulation and translocation in mangrove (Sonneratia alba) plants is known from the BCF (bioconcentration factor)  and TF (translocation factor) values. The results showed that the particle available at station I for gravel 33.55%, sand 63.38%, and mud 0.98%, at station II for gravel 28.41%, sand 70.06%, and mud 3.01 %, and at station III for gravel 49.69%, sand 51.24%, and mud 2.83%. Metal lead (Pb) content in sediments, roots, and leaves in station I were 41.53, 7.04, 2.52 mg /kg, in station II were 44.34, 1.12, 3.12 mg/kg, while in station III were 43.19, 15.37, 20.31 mg/kg, respectively. The BCF values obtained at stations I, II, and III were 0.22, 0.09, and 0.82, respectively. The TF values at stations I, II, and III were 0.35, 2.78, and 1.32, respectively.
Nessler Method Verification for Determining Ammonia in Shrimp Pond Wastewater and Its Application in the Ammonia Adsorption Test with Lampung Natural Zeolite Ni Luh Gede Ratna Juliasih; Lia Madyo Ratri; Andi Setiawan; Mita Rilyanti; Rinawati Rinawati; Agung Abadi Kiswandono; Fitri Kurniawati
ALCHEMY Jurnal Penelitian Kimia Vol 20, No 2 (2024): September
Publisher : UNIVERSITAS SEBELAS MARET (UNS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/alchemy.20.2.72456.257-266

Abstract

Ammonia levels exceeding 0.50 mg/L can threaten organisms in aquatic environments. The Nessler method is one of the ammonia analysis methods based on the reaction between ammonia in a basic solution and Nessler reagent (K2HgI4), forming a colloidal dispersion with a brownish-yellow colour. The colour intensity is determined by spectrophotometry. This research aims to verify the Nessler method for determining ammonia levels in shrimp pond wastewater. The research results indicate that the Nessler method shows good linearity in the range of ammonia concentrations from 1 to 5 mg/L, with a correlation coefficient (R2) value of 0.9962. The precision value was determined from repeatability, expressed as %RSD (Relative Standard Deviation), i.e., 1.92%, and it meets acceptance criteria, which should be less than 0.5 of the Horwitz RSD. The accuracy obtained from the standard addition method provides a percentage recovery value of 99.25%, meeting the AOAC acceptance criteria. The detection limit and quantification limit of the technique are 0.3883 mg/L and 1.2943 mg/L, respectively. The verified method is then applied to analyze shrimp pond wastewater samples from Sriminosari Village, East Lampung, resulting in an ammonia concentration of 1.52 mg/L. The ammonia levels were then reduced by adsorption with natural zeolite Lampung, decreasing ammonia levels by 20.30%. Meanwhile, adsorption with an activated zeolite reduced the ammonia levels by 45.30%.
Preparation and Characterization of Carbon/Si Nanocomposites Synthesized by Chemical Vapor Deposition (CVD) Using SiC and SiO2 Retno Duwi Hardini; Teguh Endah Saraswati; Sentot Budi Rahardjo; Alaa Keshtta
ALCHEMY Jurnal Penelitian Kimia Vol 20, No 2 (2024): September
Publisher : UNIVERSITAS SEBELAS MARET (UNS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/alchemy.20.2.80438.218-225

Abstract

Carbon-based nanocomposite materials have attracted the attention of researchers in the last decade due to their unique properties applicable in wide applications. This study aims to synthesize and study the characteristics of the carbon-based nanocomposite material produced using the chemical vapor deposition (CVD) method with SiC and SiO2. The CVD process was carried out at 900 ℃ in a vacuum with flowing argon, hydrogen, and acetylene gases. The CVD process produced nanocomposites with more sp3 hybridized carbon atoms, as indicated by the D peak in the Raman spectra. The diffraction pattern analyses show that the resulting carbon powder nanocomposite growth with SiC powder (CSiC) reveals a carbon diffraction peak C(002) and has an elongated form confirmed by an electron microscope. In comparison, the resulting carbon powder nanocomposite growth with SiO2 powder (CSiO2) has a spherical form and presents a carbon diffraction peak C(002). CSiC nanocomposites showed both symmetric and asymmetric C‒H stretching. In FTIR data, CSiO2 nanocomposites show more intense O‒H group peaks but lower-intensity C‒H group vibrations.

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