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All Journal The Journal of Pure and Applied Chemistry Research Jurnal Kimia Mulawarman Jurnal Wiyata : Penelitian Sains dan Kesehatan JURNAL ATOMIK Journal Syifa Sciences and Clinical Research (JSSCR) Indonesian Journal of Pharmaceutical Education
Riska Yudhistia Asworo
Poltekkes Kemenkes Malang
Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Chemistry Energy Environmental Science Health Professions Materials Science & Nanotechnology Medicine & Pharmacology Public Health Social Sciences Other

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Fabrication of Oxide Ceramic MgFe2O4 Using Iron Oxide Isolated from Lapindo Mud as a Raw Material Riska Yudhistia Asworo; Rachmat Triandi Tjahjanto; Akhmad Sabarudin
The Journal of Pure and Applied Chemistry Research Vol 2, No 3 (2013)
Publisher : Chemistry Department, The University of Brawijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (310.977 KB) | DOI: 10.21776/ub.jpacr.2013.002.03.156

Abstract

The quite high content (28.8%) of iron oxide (Fe2O3) in Lapindo Sidoarjo`s mud promotes as a potential raw material for fabrication of oxide ceramics. The preeminence magnetic properties of iron oxide materials have led to be widely used for preparation of noteworthy products i.e semiconductor ceramics. However, the high band gap of iron oxide results in high resistivity, limiting its application as semiconductor ceramics. The addition of other oxides to iron oxide is able to reduce the energy gap of resulted oxide ceramics. Accordingly, in this study, MgO is added to Fe2O3 isolated from Lapindo mud for preparation of the oxide ceramic MgFe2O4. The products are characterized, which include crystal structure, crystal size and resistivity. It was found that the addition of MgO decreased the volume fraction of spinel structure formation, the average of crystal size, and the resistance value. The ratio MgO/Fe2O3 of 3:7 and a sintering temperature of 1300oC show the optimum composition for fabrication of MgFe2O4 with the volume fraction of 0.72 and the crystal size of 49.06 nm as characterized by XRD.
Komparasi Daya Adsorpsi Silika Dari Abu Sekam Padi dan Ampas Tebu Terhadap Adsorpsi Pb2+ Hanandayu Widwiastuti; Riska Yudhistia Asworo
Journal Syifa Sciences and Clinical Research Vol 4, No 2 (2022): Volume 4 Edisi 2 2022
Publisher : State University of Gorontalo

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.37311/jsscr.v4i2.14910

Abstract

Heavy metals are the main pollutants which numbers are increasing . PB is a heavy metal that has high toxicity when it enters the human body. This is indicated by the LD value of 50 Pb which is 500 mg / kg body weight. Based on Government Regulation No. 82 of 2001, the maximum permissible concentration of Pb2 + in waters is 0.03 mg / L. Therefore, the presence of Pb2 + in the waters needs to be controlled so that pollution in the waters can be reduced. The purpose of this study was to determine the silica adsorption capacity of rice husks and sugarcane bagasse against Pb2 + adsorption. In this study the characterization of each adsorbent was carried out to determine the active functional groups in the bonds that occur. The maximum adsorption capacity of Pb (II) in Si-husk is 126 mg / g at 0.6 g of mass of the adsorbent while the maximum adsorption capacity of Pb (II) in Si-sugarcane is 109.69 mg / g at 0.8 g of adsorbent.
Identifikasi Kandungan Kimia Kulit Sirsak (Annona Muricata) Riska Yudhistia Asworo; Elok Widayanti; Abdullah Arief Agatha
JURNAL KIMIA MULAWARMAN Vol 19 No 2 (2022)
Publisher : Jurusan Kimia Fakultas Matematika dan Ilmu Pengetahuan Alam Universitas Mulawarman

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30872/jkm.v19i2.1140

Abstract

Pemanfaatan ekstrak bahan alam dalam biosintesis nanopartikel berkaitan dengan kandungan senyawa metabolit sekunder yang memiliki aktifitas antioksidan. Salah satu tanaman yang mengandung banyak antioksidan adalah sirsak (Annona muricata Linn). Sirsak merupakan tumbuhan yang memiliki banyak manfaat baik dari batang, kulit batang, daun maupun buahnya. Banyak penelitian telah melakukan pemanfaatan dari bagian-bagian dari tumbuhan sirsak. Tetapi belum banyak yang melakukan penelitian pada kulit buah sirsak. Seperti halnya buah manggis baik buah dan kulitnya ternyata memiliki kandungan antioksidan yang cukup tinggi. Antioksidan berasal dari senyawa metabolit sekunder yang ada di tanaman. Keberadaan metabolit sekunder ini dapat diambil dengan cara ekstraksi menggunakan pelarut yang sesuai dengan kepolaran senyawa yang akan diekstrak. Pada penelitian ini digunakan pelarut etanol dan campuran etanol:aquadest . Hasil yang didapatkan rata-rata rendemen menggunakan pelarut etanol:aquadest lebih tinggi (11,64%) dibandingkan menggunakan etanol saja (9,64%). Ekstrak yang didapatkan kemudian dilakukan uji fitokimia secara kualitatif dan didapatkan hasil adanya triterpenoid, saponin, polifenol dan tanin pada ekstrak yang didapat.
Pengaruh Ukuran Simplisia Dan Lama Kontak Pada Ekstraksi Senyawa Aktif Simplisia Kayu Jawa (Lannea Coromandelica) Menggunakan Metode Maserasi Hanandayu Widwiastuti; Riska Yudhistia Asworo; Yustina Suhandini Tjahjaningsih; Niken Cahyaning Wulandari; Abriyanti Dewi
JURNAL KIMIA MULAWARMAN Vol 19 No 2 (2022)
Publisher : Jurusan Kimia Fakultas Matematika dan Ilmu Pengetahuan Alam Universitas Mulawarman

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30872/jkm.v19i2.1141

Abstract

Kayu Jawa atau Kayu Jaranan merupakan tanaman yang banyak tumbuh di Pulau Jawa dan umumnya digunakan sebagai pagar pembatas. Namun, di beberapa daerah di Indonesia, tanaman ini seringkali digunakan untuk pengobatan tradisional. Beberapa metabolit sekunder yang diketahui terkandung dalam Kayu Jawa adalah steroid, terpenoid, alkaloid, saponin, tanin, dan flavonoid. Bioaktivitas ekstrak senyawa – senyawa ini dipengaruhi oleh jumlah gugus aktif yang ada pada senyawa tersebut, salah satunya adalah gugus hidroksil. Salah satu senyawa aktif yang memiliki banyak gugus – OH adalah tanin. Gugus ortohidroksil tanin dapat membentuk kelat dengan ion logam. Fungsi tanin sangat dipengaruhi oleh konsentrasinya, apakah berfungsi sebagai agen pengompleks atau agen pengendap. Oleh karena itu, ekstraksi tanin perlu dilakukan secara optimum untuk memperoleh tanin dalam jumlah maksimal. Tujuan penelitian ini adalah untuk mengetahui pengaruh ukuran simplisia waktu kontak terhadap jumlah rendemen yang diperoleh dari ekstraksi Kayu Jawa dengan metode maserasi. Hasil penelitian menunjukkan bahwa jumlah rendemen terbesar dihasilkan pada maserasi dengan ukuran simplisia > 200 mesh dan lama kontak 50 jam, yaitu 23,79% dan 23,01%. Berdasarkan hasil tersebut dapat disimpulkan bahwa ukuran simplisia dan waktu kontak berpengaruh terhadap jumlah rendemen hasil maserasi simplisia Kayu Jawa.
Pengaruh Ukuran Serbuk Simplisia dan Waktu Maserasi terhadap Aktivitas Antioksidan Ekstrak Kulit Sirsak Riska Yudhistia Asworo; Hanandayu Widwiastuti
Indonesian Journal of Pharmaceutical Education Vol 3, No 2 (2023): Mei-Agustus 2023
Publisher : Jurusan Farmasi Universitas Negeri Gorontalo

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.37311/ijpe.v3i2.19906

Abstract

Secondary metabolites are one of the active substances in natural materials that are known to contain high antioxidants and are very beneficial for health. In addition to mangosteen, there are also natural ingredients that actually have high antioxidant content, but many people do not know about it, one of which is soursop fruit. In addition to the fruit, the skin of soursop fruit may contain antioxidants that are quite high. The purpose of this study was to determine the effect of different maceration times and powder sizes on the antioxidant activity of secondary metabolite compounds produced from ethanol-aquades extract of soursop fruit peel (Annona muricata L.). This study was conducted quantitatively with a descriptive research design where researchers conducted laboratory research conducted in triplo. This research used particle size variation of 50 mesh, 100 mesh, and 200 mesh and maceration time variation of 24 hours, 30 hours, 36 hours. From this study it can be seen that the difference in powder size and maceration time affects the results of antioxidant activity obtained. The optimum particle variation is using 200 mesh size, which is obtained antioxidant activity of 95.2%. While the optimum maceration time is for 24 hours, the yield is 94%. From this study it can also be seen that the ethanol-aquades extract of soursop fruit peel contains secondary metabolite compounds of triterpenoids, saponins, polyphenols and tannins.
ANALYSIS OF RHODAMINE B IN LIP CREAM USING COLORIMETRIC METHOD BY DIGITAL IMAGING Jauhar Fatin Muna; Riska Yudhistia Asworo
Jurnal Wiyata Penelitian Sains dan Kesehatan Vol 10, No 1 (2023)
Publisher : LP2M IIK (Lembaga Penelitian dan Pengabdian Masyarakat Institut Ilmu Kesehatan) Bhakti Wiy

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.56710/wiyata.v10i1.594

Abstract

Background: lip cream is one type of lip color often used by women. Beside it, there are still some manufacturers add Rhodamine B to lip color, especially lip cream. This is very dangerous for the health of consumers. Therefore, it is necessary to analysis of Rhodamine B in samples red lip cream. Objective: the purpose of this research to analysis Rhodamin B contained in lip cream using colorimetric method by digital imaging. Method: the method of this research is colorimetric method by digital imaging. This method is a simple, low budget,  easy, and fast method. Result: the standard curve Zn-thiocyanate-Rhodamine B solution of RGB components, shows the result is green component curve has a good R2 value is 0,9992 with the linear regression equation y = 0,0423x + 0,1335. Accuracy expressed as % recovery, shows good results with an average value of 100,7%. Determination of the precision value also shows good result, the RSD value obatained is 1,96%. So that, the colorimetric method by digital imaging can be used to analysis of Rhodamine B in samples. Conclusions: sample A and B positive Rhodamine B with concentrations of 0,6730 ppm and 0,0488 ppm.
Sintesis Nanopartikel Perak menggunakan Ekstrak Kulit Sirsak sebagai Bioreduktor Riska Yudhistia Asworo; Hanandayu Widwiastuti; Elok Widayanti
Indonesian Journal of Pharmaceutical Education Vol 3, No 3 (2023): September-Desember 2023
Publisher : Jurusan Farmasi Universitas Negeri Gorontalo

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.37311/ijpe.v3i3.22310

Abstract

Soursop peel can be used as a bioreductor in the green synthesis process of silver nanoparticle formation. This is because the content of secondary metabolite compounds in soursop peel can reduce Ag3+ to Ag0 in nano size. Secondary metabolites in soursop peel are obtained by extraction using a solvent whose polarity value is close to the polarity value of soursop peel secondary metabolites. In this study, ethanol-aquadest and ethanol solvents were used. The extract obtained was then formulated with AgNO3 solution with a concentration variation of 0.5; 1; 1.5 and 2 mM to determine the optimum concentration on the formation of silver nanoparticles. The maximum concentration was obtained at a concentration of 2 mM AgNO3, seen from the highest absorbance obtained at the maximum wavelength observation of 400-450 nm with the concentration of AgNO3 used 2 mM. The silver nanoparticles formed were then analysed using a Particle Size Analyzer (PSA) to determine the size of the nanoparticles formed. Nanoparticles using ethanol-aquadest solvent had a size of 92.83 nm, while those using ethanol solvent had a size of 301.3 nm.
Pengaruh Massa Biosorben Kulit Batang Kayu Jawa (Lannea coromandelica) terhadap Kapasitas Adsorpsi Ion Cd(II) Niken Cahyaning Wulandari; Hanandayu Widwiastuti; Riska Yudhistia Asworo
JURNAL ATOMIK Vol 8 No 2 (2023): Vol 8 No 2 (2023)
Publisher : Jurusan Kimia FMIPA UNMUL

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30872/ja.v8i2.1230

Abstract

Cadmium is one of the heavy metals that can contaminate bottled drinking water (AMDK) and cause health problems if its concentration more than the maximum limit. According to SNI 01-3553-2006, the maximum concentration of cadmium in AMDK is 0.003 mg/L. An effective method to reduce Cd levels is adsorption. In this research, use material diversification by utilizing Java Bark as biosorbent. This is because the Java Bark contains tannin compounds that can bind heavy metals. One of the factor that can affect adsorption is biosorbent mass. The aims of study is determine the effect of Java Bark biosorbent mass to the adsorption capacity of Cd(II) by Atomic Absorption Spectrophotometry (AAS). Java Bark biosorbent mass used were 0.1; 0.5; 1; 1.5; and 2 g. The results showed that the biosorbent mass of 0.1 g had the largest adsorption capacity of 9.47 mg/g. Meanwhile, the adsorption capacity of the biosorbent mass of 0.5-2 g tends to decrease because the surface of the biosorbent has been saturated and particle aggregation so that Cd(II) desorption. From the results of the study, it can be concluded that the Java Bark biosorbent with a mass of 0.1 g has the largest adsorption capacity for adsorption Cd(II).
Co-Authors Abdullah Arief Agatha Abriyanti Dewi Akhmad Sabarudin Elok Widayanti Elok Widayanti Hanandayu Widwiastuti Hanandayu Widwiastuti Hanandayu Widwiastuti Jauhar Fatin Muna Niken Cahyaning Wulandari Niken Cahyaning Wulandari Rachmat Triandi Tjahjanto Yustina Suhandini Tjahjaningsih