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The Effect of Solvent-to-Coffee Ratio on Caffeine Content in Ethyl Acetate Extracts of Arabica Gayo Coffee Beans Soeswanto, Bambang; Sihombing, Rony Pasonang; Suryadi, Joko; Hariyadi, Tri; Paramitha, Tifa; Yusuf, Yusmardhany; -, Alfiana Adhitasari
KOVALEN: Jurnal Riset Kimia Vol. 9 No. 3 (2023): December Edition
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2023.v9.i3.16573

Abstract

This paper studies the optimal ratio that gives the highest caffeine amount and improves the efficiency and quality of extraction from Arabica Gayo coffee beans. No previous studies have explored the best ratio of Gayo Arabica coffee beans to ethyl acetate solvent for extracting caffeine. The paper explains the method used, which has four main steps: preparing materials, extracting and measuring caffeine, and analyzing the results. The paper presents the experimental findings and discusses how different ratios affect caffeine content in Arabica Gayo coffee beans. It uses statistics to show significant differences between the ratios and compares them using Tukey tests. The paper concludes that the best solvent-to-coffee ratio for maximizing caffeine in ethyl acetate extracts is 1:5, resulting in a concentration of 1411.1 ppm. This ratio gives the best balance between caffeine yield and solvent usage.
The Effect of Variations in Sulfuric Acid - Oxalic Acid Electrolyte Concentration and Additional Aeration on 1100 Series Aluminum Anodization Results Leoanggraini, Unung; Irianto, Indra; Aji, Restu; Paramitha, Tifa; Sihombing, Rony
Journal of Green Science and Technology Vol 8 No 2 (2024): Journal of Green Science and Technology Vol.8 No.2 September 2024
Publisher : Faculty of Engineering, Universitas Swadaya Gunung Jati

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33603/jgst.v8i2.9425

Abstract

Aluminum is one of the materials used in making various types of goods because it has good properties such as being light, ductile and has good corrosion resistance. One of the disadvantages of aluminum is its low level of hardness. This can be overcome by treating aluminum, one of which is the anodization process. In this research, variations in the type of electrolyte used were sulfuric acid-oxalic acid, the electrolyte concentration was 16% with an interval of 0.5, the temperature used was room temperature with a current density of 3/dm2 and a coating time of 30 minutes. The aim of this research is to determine the acid concentration and the effect of the aeration system on mechanical properties. From the data obtained, it was found that the difference in weight of the best metal with the addition of aeration at a concentration of 13.5+2.5 was 0.0411 gr. This shows that as the concentration of oxalic acid increases it can accelerate the process of aluminum oxide formation, then for electrolyte concentrations of 16+0, 15.5+0.5, 15+1, 14.5+1.5 and 14+2 the difference in mass weight metals increased respectively by 0.0337 gr, 0.0335 gr, 0.0366 gr, 0.0390 and 0.0411 gr. In the anodization process without   additional aeration, the best metal weight difference is found at an electrolyte concentration of 13.5+2.5 of 0.0401 gr. This shows that increasing the concentration of oxalic acid can accelerate the process of aluminum oxide formation. Then at electrolyte concentrations of 16+0, 15.5+0.5, 15+1, 14.5+1.5 and 14+2 the difference in metal mass weight gradually increases by 0.0182 gr, 0.0293 gr, 0.0318 gr, 0.0322 and 0.0362 gr. Keywords: Aluminum, Anodization, Oxide Coating, Electrolyte Solution, Sulfuric Acid, Oxalic acid
Utilization of Coconut Shell and Coffee Grounds as Briquettes Using the Carbonization Method Adhitasari, Alfiana; Manfaati, Rintis; Paramitha, Tifa; Zahwa, Keisya Adellia; Setiawan, Kiranna Shalmadevy; Yusuf, Yusmardhany
Eksergi Vol 22 No 3 (2025)
Publisher : Prodi Teknik Kimia UPN "Veteran" Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31315/eksergi.v22i3.15128

Abstract

Biomass-based briquettes offer a renewable energy alternative that can help reduce CO₂ emissions. Coconut shells and coffee grounds are promising waste materials due to their high calorific value. This study aimed to optimize the composition and carbonization time in producing briquettes from these two materials. The briquettes were prepared following SNI 01-6235-2000 and export briquette standards. The process included drying, carbonization at 300 °C for 60, 90, 120, 150, and 180 minutes, sieving, mixing, molding, and drying. Coconut shells and coffee grounds were mixed at weight ratios of 9:1, 8:2, 7:3, 6:4, and 5:5 with a total of 46.5 grams and 8.5 grams of adhesive. Briquette quality was evaluated based on moisture content, ash content, volatile matter, density, calorific value, and fixed carbon. The 9:1 composition yielded the highest calorific value of 6,472 cal/g, while a carbonization time of 90 minutes produced the best calorific value of 6,504 cal/g. The results show that a high proportion of coconut shells with limited coffee grounds and optimal carbonization time can produce briquettes with high energy potential, suitable for use as an alternative fuel.
Utilization of Natural Zeolite Impregnated with Fe for Decolorization of Methylene Blue Paramitha, Tifa; Aulia, Bunga; Azzahra, Tarisha Aulia; Taufiqurohim, Teguh; Adhitasari, Alfiana
Indonesian Journal of Chemical Research Vol 13 No 3 (2026): Edition for January 2026
Publisher : Jurusan Kimia, Fakultas Sains dan Teknologi, Universitas Pattimura

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30598/ijcr.2026.13-tif

Abstract

Wastewater containing methylene blue, discharged into rivers, significantly impacts water quality due to its resistance to natural degradation. This study investigated the treatment of methylene blue using the photo-Fenton method, employing UV light to generate hydroxyl radicals (•OH) through the reaction of hydrogen peroxide (H₂O₂) and Fe catalyst. Natural zeolite was used as a support material, activated with NaOH solution, and impregnated with FeSO₄·7H₂O. Semi-quantitative EDS analysis indicated an iron content of 6.2 wt%. The XRD result shows that the crystalline iron phase was hematite. The photo-Fenton experiments were performed at a catalyst dosage of 0.1 g/L to degrade methylene blue with an initial concentration of 20 mg/L by varying pH levels (3, 5, 7) and H₂O₂ concentrations (15, 30, 45 mM). The optimal conditions were found to be a combination of 45 mM H₂O₂ concentration, pH 3, and under 365 nm UV lamp irradiation, achieving a maximum decolorization efficiency of 99.77% at 120 minutes. H₂O₂ concentration did not significantly affect final decolorization percentage, indicating that excess H₂O₂ does not enhance degradation beyond a certain threshold. The lowest final methylene blue concentration achieved was 0.05 mg/L, and the final chemical oxygen demand (COD) was reduced to 243.6 mg/L.
Sintesis dan Karakterisasi Semikonduktor TiO2 Doping Magnesium dengan Metode Hidrotermal: Synthesis and Characterization of Magnesium Doped TiO2 Semiconductor by Hydrothermal Method Paramitha, Tika; Utami, Khoirunnisa; Anggraini, Yuki Martha; Paramitha, Tifa
KOVALEN: Jurnal Riset Kimia Vol. 9 No. 1 (2023): April Edition
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2023.v9.i1.16275

Abstract

Semiconductors are materials that range between insulators and conductors in terms of conductivity value. Titanium Dioxide (TiO2) is a semiconductor that is widely applied to various things. TiO2 has the benefits, such as being environmentally stable and inexpensive. TiO2 is photoactive in the range of ultraviolet radiation due to the band gap value of 3.2 eV. However, ultraviolet is only produced from 5% of sunlight. The research aimed to narrow the band gap energy so as to maximize light absorption. This is done by modification with the addition of Mg elements to TiO2 materials at different mass variations of Mg (1%, 1.5%, 2%) to the mass of TiO2 which is often referred to as doping. TiO2 was doped by Mg using a hydrothermal method for 24 hours with a temperature of 180áµ’C, followed by 2 hours of calcination at 400áµ’C. Then, TiO2 and Mg-doped TiO2 particles were characterized by SEM-EDX, FTIR, and UV-Vis. Based on the results of TiO2 and Mg-doped TiO2 particle characterization using SEM, both particles are spherical in shape. The success of Mg doping was identified from the data of EDX characterization, which revealed that the mass % of the Mg component increased with the greater Mg doping concentration on TiO2 particles. There was no structural change following Mg doping on TiO2 particles, as evidenced by the same peak based on the results of FTIR characterization of TiO2 and Mg-doped TiO2 particles. Moreover, a 2% Mg mass doping on pure TiO2 resulted in a decrease in band gap energy to 3.16 eV, in which the pure TiO2 was 3.39 eV. The mass doping of Mg on TiO2 required further optimization to obtain the maximum band gap energy reduction for photocatalytic applications.
Anodizing Characteristics of AA1100 in 20% Sulfuric–Phosphoric Acid Electrolytes under Aerated and Non-Aerated Conditions at Various Times Tri Hariyadi; Tita Rosita; Aniqa Arjumand Bano Harvani; Silvia Fatimatur Rahmawati; Tifa Paramitha; Adhitasari, Alfiana; Sihombing, Rony
Journal of Green Science and Technology Vol 10 No 1 (2026): Journal of Green Science and Technology Vol. 10 No.1 March 2026
Publisher : Faculty of Engineering, Universitas Swadaya Gunung Jati

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33603/jgst.v10i1.11796

Abstract

Aluminum alloy AA1100 exhibits good corrosion resistance but suffers from low surface hardness and wear resistance, which can be improved through anodizing. However, limited studies have examined the combined influence of sulfuric–phosphoric acid electrolyte composition and aeration. This study investigates the effect of sulfuric–phosphoric acid electrolyte composition and aeration on oxide layer mass, thickness, and hardness during anodizing. Anodization was conducted using a total electrolyte concentration of 20% with varying sulfuric acid (15–20%) and phosphoric acid (5–0%) ratios at a current density of 3 A/dm², operating times of 15 and 30 minutes, and room temperature under aerated and non-aerated conditions. The results show that aeration significantly increased oxide layer formation, yielding an average oxide mass of 0.0173 g compared to 0.0106 g in non-aerated systems. The maximum oxide mass (0.0375 g) was obtained at 20% sulfuric acid with aeration for 30 minutes. The highest oxide layer thickness of 47.94 µm was achieved using a 19% sulfuric acid–1% phosphoric acid electrolyte under aerated conditions at 30 minutes. Meanwhile, the maximum surface hardness of 352.60 HVN was obtained at 15% sulfuric acid–5% phosphoric acid with aeration for 15 minutes. These findings demonstrate that electrolyte composition and aeration play a critical role in optimizing anodic oxide growth and mechanical properties of AA1100.
Co-Authors -, Alfiana Adhitasari Agustin, Delliana Aji, Restu Alatif, Ikhsan Akmal Alfiana Adhitasari Amelia Nur Aliah Andrijanto, Eko Anggraini, Yuki Martha Aniqa Arjumand Bano Harvani Arijan Vevayose Tarigan Aulia, Bunga Azzahra, Rafila Chika Azzahra, Tarisha Aulia Bambang Soeswanto binti Jamaluddin, Jamarosliza Dwi Irmawati, Dwi Elizabeth, Lidya Endang Kusumawati Endang Kusumawati Gamaliel Tanaka Hariyadi, Tri Herawati Budiastuti Heru Hermawan Hidayatulloh, Irwan Irianto, Indra Jayanti, Retno Dwi Kharisma, Luthfiana Kurnia, Dianty Rosirda Dewi Lestari Herlianti Putri Luviana, Angely Malik, Dava Maulana Manfaati, Rintis Muhammad Misbahussalam Muhari, Emma Hermawati Mukhtar Ghozali Ngatin, Agustinus Nidaulhusna, Anisa Nirmala Utami Nurbaits, Alisya Nurhasanah, Santy Nurul Annisa Nurulgina, Rahma Permatasari, Rahma Puspa Putri, Angelina Rachmawati, Anissa Nurul Rahma Ardelia Raissa Rahmawati, Sri Puji Ramadhan, Muhammad Zikri Ramadhani, Laily lsna Retno Indarti Reynaldi, Randi Rivaldo Rofie Fauzi Budiman Rizky Setianto Robby Sudarman Rusdianasari Rusdianasari Sabinna Azahra Sulaeman Salsabila, Iva Najwa Salsabila, Salwa Ainaya Salsabila, Shafira Salsabilla, Iva Najwa Sari, Radianti Novita Setiawan, Kiranna Shalmadevy Setyaningrum, Sinta Shafira Yulianthina Sihombing, Rony Sihombing, Rony Pasonang Silvia Fatimatur Rahmawati Suryadi, Joko Teguh Aditya Nugraha Teguh Taufiqurohim Tika Paramitha Tika Paramitha Tita Rosita Tri Hariyadi Tri Reksa Saputra Trirahayu, Dhyna Analyes Unung Leoanggraini Utami, Khoirunnisa Wardana Putra, Adzikri Yusuf, Yusmardhany Zahwa, Keisya Adellia