cover
Article Per Year (5 Year)
All
Home Page
OAI Link
Editorial Team
Contact
Reviewer
Google Scholar
Contact Name
-
Contact Email
-
Phone
-
Journal Mail Official
jurnalrisetkimia@sci.unand.ac.id
Editorial Address
Department of Chemistry Faculty of Mathematics and Natural Sciences Universitas Andalas Kampus Universitas Andalas Limau Manih Padang 25163
Location
Kota padang,
Sumatera barat
INDONESIA
Jurnal Riset Kimia
Published by Universitas Andalas
ISSN : 1978628X     EISSN : 24768960     DOI : -
Core Subject : Science,
Chemistry
Arjuna Subject : -
Articles 551 Documents
 40   41   42   43   44 
VALIDASI METODA FRAP MODIFIKASI PADA PENENTUAN KANDUNGAN ANTIOKSIDAN TOTAL DALAM SAMPEL MANGGA DAN RAMBUTAN Yefrida -; Nor Ashikin; Nor Ashikin; Refilda -; Refilda -
Jurnal Riset Kimia Vol. 8 No. 2 (2015): March
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v8i2.236

Abstract

Validation of modified FRAP method to determine total antioxidant content in mango and rambutan sample have been done. Total antioxidan content in sampel is presented as Gallic Acid Equivalent (GAE). Modified FRAP method using FeCl3asoxidizing agent and ortho-phenantroline as complexan, which produce complex compounds of [Fe (C12H8N2)3]+2 sorrel coloured. Validation parameters are obtained in this research are r = 0.999, R2 = 0.998, LoD 3.13 x 10-6 M and LoQ 1.04 x 10-5 M. While RSD and recovery in the sample mango and rambutan were 1.15%, 1.34% and 96.31%, 97.72%, respectively. Based on the value of the validation parameters, it can be concluded that this method can be used for determination of total antioxidant content in the mango and rambutan samples.
STUDI HANTARAN LISTRIK SENYAWA SRN+1TINO3N+1 (N = 1 DAN 2) FASA RUDDLESDEN-POPPER YANG DISINTESIS DENGAN METODE LELEHAN GARAM Yulia Eka Putri; Hamsal Yusri; Zulhadjri -
Jurnal Riset Kimia Vol. 8 No. 2 (2015): March
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v8i2.237

Abstract

Srn+1TinO3n+1 (n = 1, 2,...n)Ruddlesden-Popper phase is a metal oxide compound with a layered structure consisting of SrTiO3 perovskite layers and strontium oxide (SrO) layers, thus this material has a potential as termoeletrik compounds that could be developed as an alternative material for renewable energy. In this study, we examine one of the 3 parameters of termoelectric properties, namely the electrical conductivity. Srn+1TinO3n+1 (n = 1 and 2)Ruddlesden-Popper phases were synthesized using molten salt method. The synthesis was carried out at 950 °C for 10 hours with a ratio of precursor and salt were 1: 0.5. Structural analysis by X-Ray Diffractometer (XRD) confirmed that all synthesized compounds formed Srn+1TinO3n+1 (n = 1, and 2) Ruddlesden-Popper phase with the characteristic peaks at 2q = 31o, 32o, and 46o. The morphology analysis by Scanning Electron Microscope (SEM) showed that the particles have plate-shaped with crystallites size were 20 nm. The electrical properties were measured using LCR meter with the highest electrical conductivity of 2.25x10-7 S / cm which showed the semiconductors behaviour.
PENGARUH BEBERAPA PERLAKUAN TERHADAP PENGURANGAN KADAR FORMALIN PADA IKAN YANG DITENTUKAN SECARA SPEKTROFOTOMETRI Yulizar Yusuf; Zamzibar Zuki; Ruci Riski Amanda
Jurnal Riset Kimia Vol. 8 No. 2 (2015): March
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v8i2.238

Abstract

The case of how handling the fresh fish which used the dangerous chemical material (formaldehyde) is still found in society, so that is why it is necesarry to find the safety way to handle the fresh fish in. It has been held the research about the influence of on the effect of some treatment in reduction the formaldehyde level on fish determined by spectrophotometry UV-Visible at wavelength 412 nm and 40°C. In the preliminary research the fish is soaked in formaldehyde liquid (100 mg/mL) for 24 hours, then washed, soaked and boiled. Then, the filtrate is reacted with Nash reagent. The yellow color which has formed was measured at λ 412 nm. The result shows there is the reduction of formaldehyde level in the sample about 43.9 % after washing, 33.3 % after soaking, 53.8 % after boiling. After that, the fish that was spread in the market which suspected containing the formaldehyde then washed, soaked and boiled. The result shows there is the reduction of formalin level in sample 1 about 22,7 % after washing, 17.0% after soaking, and 96.1 % after boiling. While in sample 2, 41.8 % after washing, 56.2 % after soaking, and 95.4 % after boiling.
PENYERAPAN ION LOGAM Cr(III) DAN Cr(VI) DALAM LARUTAN MENGGUNAKAN KULIT BUAH JENGKOL (Pithecellobium jiringa (JACK) PRAIN.) Zulkarnain Chaidir; Qomariah Hasanah; Rahmiana Zein
Jurnal Riset Kimia Vol. 8 No. 2 (2015): March
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v8i2.239

Abstract

Jengkol shells (Pithecellobium jiringa) an agricultural waste from typical Indonesian plant has been investigated for its ability to absorb heavy metal ions Cr VI and Cr III . Effect of pH, concentration, contact time, mass and the speed of stirring biosorben studied by extraction method. Concentration of metal ions Cr VI and Cr III was measured using Atomic Absorption Spectrophotometer (AAS). The optimum conditions for metal ion uptake of Cr VI occurs at pH 4, the concentration of 7000 mg/L, contact time of 60 minutes, 0.1 g biosorben mass and stirring speed 100 rpm. For the metal ions Cr III wa obtained conditions optimum at pH 5, the concentration of 1500 mg/L,  contact time of 60 minutes, 0.1 g biosorben mass and stirring speed 100 rpm. Functional groups contained in the jengkol shells analyzed by Fourier Transform Infra Red (FTIR). Data equilibrium uptake of metal ions Cr VI and Cr III  by the jengkol shells analyzed using two isotherm models , namely Langmuir and Freundlich isotherm models . The absorption of both the metal ions tend to follow the Langmuir isotherm models in which the absorption capacity of metal ions obtained for Cr VI ) and Cr  III  is 24.9376 mg / g and 39. 0625 mg /g . The optimum condition was applied to study the river Batang Arau at Padang city obtained a capacity of 15.065 mg/ g with 45 efficiency, 94 % for the uptake of metal ions Cr (total).
ANALISIS ZAT WARNA TARTRAZIN PADA JAJANAN MINUMAN RINGAN TAK BERLABEL YANG DIJUAL PEDAGANG KAKI LIMA DI BANDA ACEH Bhayu Gita Bhernama
Jurnal Riset Kimia Vol. 9 No. 2 (2016): March
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v9i2.241

Abstract

Analisis zat warna Tartrazin pada jajanan minuman ringan tak berlabel yang dijual pedagang kaki lima di Banda aceh telah dilakukan. Zat warna Tartrazin merupakan pewarna sintetis yang digunakan oleh masyarakat sebagai bahan tambah pangan (BTP), guna meningkatkan daya tarik minuman. Analisis zat warna Tartrazin pada jajanan minuman ringan tak berlabel yang dijual pedagang kaki lima di Banda aceh bertujuan untuk mengetahui ada atau tidaknya kandungan zat warna Tartrazin dan menentukan kadar zat warna Tartrazin yang terdapat pada jajanan minuman ringan tak berlabel yang dijual pedagang kaki lima. Hasil analisis didapatkan kadar zar warna Tartrazin pada panjang gelombang 427 nm sekitar 1,06457- 40,6126 ppm. Kadar zat warna Tartrazin melebihi batas yang telah ditetapkan berdasarkan ADI (Acceptable Daily Intake) yaitu sekitar 7,5 mg/Kg/day. KBPOM RI No. 37 Tahun 2013 tentang batas maksimum penggunaan BTP pewarna ditetapkan bahwa pewarna Tartrazin yang diizinkan 70  mg/Kg
ISOLASI DAN KARAKTERISASI METABOLIT SEKUNDER DARI EKSTRAK ASETON DAUN MACARANGA PRUINOSA BANGKA BELITUNG Occa Roanisca; Yana M. Syah
Jurnal Riset Kimia Vol. 9 No. 2 (2016): March
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v9i2.248

Abstract

Macaranga is a large genus in Euphorbiaceae, locally known as "Mahang-mahangan", and consisting about 300 species. Distribution of Macaranga is widespread from Africa and Madagascar in the west to the tropical regions of Asia including Indonesia. Based on previous research of the M. pruinosa, secondary metabolites that have been reported are flavonoid, and stilbenoid derivatives from Borneo. M. pruinosa that grow in South Sumatra produce poilanoat acid (diterpene). Therefore, this research is done to investigate phytochemical constituent of leaves of M. pruinosa from Bangka Belitung Islands. Isolation is done by maceration in acetone, separation and purification using vacuum liquid chromatography and radial chromatography. Structure determination were elucidated by 1H-NMR,13C-NMR, 2D NMR. Two compounds are identified as flavanon derivatives. They are nymphaeol B, and 6-farnesil-3',4',5,7-tetrahidroksiflavanon. These compounds are substituted with terphenyl group, known as geranyl (C10), and farnesyl (C15). Nymphaeol B (1) and compound of 6-farnesil-3', 4', 5,7-tetrahidroksiflavanon (2) have been found in other species of Macaranga. In conclusion, we here acquired two phenolic derivatives substituted by terphenyl groups from acetone extracts of leaves of M. pruinosa from Bangka Belitung. They are nymphaeol B, and 6-farnesil-3',4',5,7-tetrahidroksiflavanon. The result showed that M.pruinosa can produce different secondary metabolites depend on where they grow. 
ISOLASI DAN ELUSIDASI STRUKTUR SENYAWA TRITERPENOID DARI KULIT BATANG AMBACANG (Mangifera foetida L.) SERTA UJI BRINE SHRIMP LETALITY TEST (BSLT) Adlis Santoni; Sabariah -; Mai Efdi
Jurnal Riset Kimia Vol. 9 No. 1 (2015): September
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v9i1.252

Abstract

A brine shrimp toxic compound has been isolated from Mangifera foetida L. steam bark. Based on spectroscopic data (IR,1H- NMR, 13C-NMR 1D and 2D), the structure of this compound was identified as mangiferenes B, C30H47O2. In this study, the n-hexane, ethyl acetate, methanol extracts and isolated compound showed toxic effects (LC50 471.9543; 534.5209, 678.4421, and 22.1615 μg/mL, respectively). The toxicity degree among the three extracts and isolated compound is isolated compound > n-hexane extract > ethyl acetate extract > methanol extract.
PEROLEHAN GLUKOSA DENGAN HIDROLISIS ENZIMATIS DARI AMPAS TEBU MENGGUNAKAN Trichoderma viride DAN Aspergilus niger SEBAGAI BAHAN BAKU BIOETANOL Elita Sari; Elly Desni Rahman; Munas Martynis; Shafira Fiona; Junialdi -
Jurnal Riset Kimia Vol. 9 No. 1 (2015): September
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v9i1.253

Abstract

Lignocellulosic biomass is a rich agricultural waste containing cellulose and hemicellulose. Bagasse (bagasse) is one of the waste biomass containing cellulose and hemicellulose approximately 47.7% which can be used to produce bioethanol. Enzymatic process is able to hydrolysis the polysaccharide compound into its constituent, sugars monomer compound. An enzymatic hydrolysis process converts cellulose to glucose by using cellulase enzymes. Some microorganisms producing the enzyme cellulase are Trichoderma viride and Aspergillus niger. The purpose of this research is to find out comparison of both these microorganism as a catalyst in the enzymatic hydrolysis process that produces the highest glucose levels and hydrolysis time. Hydrolysis process is done by varying the ratio between Tricoderma viride and Aspergillus niger of 1: 0; 0: 1; 0.5: 1 and 1: 0.5 and  time sampling  24, 48, 72, 96, 120. The results showed glucose acquisition as much as 360 mg/L with hidrolysis process  by hotplate  stirer and 660 mg/L with process by waterbath shaker at composition ratio of Trichoderma viride: Aspergillus niger 1: 0.5 and the hydrolysis time is 96 hours.
PEMANFAATAN ABU KULIT KAKAO UNTUK PEMBUATAN BATU BATA Mulyazmi -; Erti Praputri; Zulfiandriana -; Widya Wahyuni
Jurnal Riset Kimia Vol. 9 No. 1 (2015): September
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v9i1.254

Abstract

Brick is one of building materials derived from clay. The manufacturing process is with or without the use of substances mixing with the process of combustion at high temperatures. One of the mixing substances is derived from the rind cacao ash and its function is as an adhesive on the bricks.The purpose of this research is to understand the characteristics of brick as effect of cocoa rind as the value of compressive strength, porosity, water absorption and weight of a brick. The main materials of brick production are clays and trass ground which are mixed homogeneous with ratio 1 : 2 by varying cocoa rind ash additional by 5%, 10%, and 15%. The result is the compressive strength of the bricks using rind cocoa ash is 392.2 kg/cm3 higher value than traditional brick is 56.1 kg/cm3.
PENGARUH WAKTU REAKSI DAN RASIO MOL ASAM LINOLEAT DENGAN ISOPROPANOL PADA SINTESA PLASTISIZER ISOPROPIL LINOLEAT Nirwana -; Irdoni HS -; Joni Miharyono
Jurnal Riset Kimia Vol. 9 No. 1 (2015): September
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v9i1.255

Abstract

Diversity of palm oil product in Indonesia is still limited, therefore it is needed to take an advantage of the development of downstream product of crude palm oil by esterification reaction. Esterification reaction is a reaction between carboxylic acid and alcohol to form ester. One of the emerging downstream product fatty acid alkyl ester is plasticizer. Plasticizer is an additive compound added to polymer to improve flexibility and workability. The purpose of this research was conducted to study the effect of reaction time and mole ratio and identify product of plasticizers isopropyl linoleic. In this research, plasticizer was synthesized by esterification of linoleic acid and isopropanol, using activated natural zeolite catalyst. The process was done with a variation of reaction time (4, 6, and 8 hours) and mole ratio (1: 6, 1: 9, and 1:12), with reaction temperature at  80 °C,  stirring speed at 200 rpm and 15% of composition of linoleic acid based catalyst as fixed variables. From the analysis of the results showed that the esterification reaction time and mole ratio affect the product conversion. The best operating condition obtained  in this research was 4 hours of reaction time and 1:12 of mole ratio which resulted the conversion of reaction was 67.09%. Characteristics of plasticizer produced from this research were viscosity (at 20 °C) 2.405 to 2.803 mPa.s and Specific Gravity (at 20 °C) from 0.863 to 0.872.

Page 42 of 56 | Total Record : 551

 40   41   42   43   44 

Filter by Year

2007 2025


Reset
Filter By Issues
All Issue Vol. 16 No. 2 (2025): September Vol. 16 No. 1 (2025): March Vol. 15 No. 2 (2024): September Vol. 15 No. 1 (2024): March Vol. 14 No. 2 (2023): September Vol. 14 No. 1 (2023): March Vol. 13 No. 2 (2022): September Vol. 13 No. 1 (2022): March Vol 13, No 1 (2022): March Vol 12, No 2 (2021): September Vol. 12 No. 2 (2021): September Vol. 12 No. 1 (2021): March Vol 12, No 1 (2021): March Vol. 11 No. 2 (2020): September Vol 11, No 2 (2020): September Vol 11, No 1 (2020): March Vol. 11 No. 1 (2020): March Vol 10, No 2 (2019): September Vol. 10 No. 2 (2019): September Vol 10, No 1 (2019): March Vol. 10 No. 1 (2019): March Vol 10, No 1 (2019): March Vol. 9 No. 2 (2016): March Vol 9, No 2 (2016): March Vol. 9 No. 1 (2015): September Vol 9, No 1 (2015): September Vol 8, No 2 (2015): March Vol. 8 No. 2 (2015): March Vol 7, No 2 (2014): March Vol. 7 No. 2 (2014): March Vol. 5 No. 2 (2012): March Vol 5, No 2 (2012): March Vol 5, No 1 (2011): September Vol. 5 No. 1 (2011): September Vol 4, No 2 (2011): March Vol. 4 No. 2 (2011): March Vol. 4 No. 1 (2010): September Vol 4, No 1 (2010): September Vol. 3 No. 2 (2010): March Vol 3, No 2 (2010): March Vol 3, No 1 (2009): September Vol. 3 No. 1 (2009): September Vol. 2 No. 2 (2009): March Vol 2, No 2 (2009): March Vol 2, No 1 (2008): September Vol. 2 No. 1 (2008): September Vol. 1 No. 2 (2008): March Vol 1, No 2 (2008): March Vol 1, No 1 (2007): September Vol. 1 No. 1 (2007): September More Issue