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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
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DEGRADASI SENYAWA PARAQUAT DALAM PESTISIDA GRAMOXONE® SECARA SONOZOLISIS DENGAN PENAMBAHAN TiO2-ANATASE Yenni, Neila; Safni, Safni; Suyani, Hamzar
Jurnal Riset Kimia Vol 3, No 2 (2010): March
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v3i2.58

Abstract

 ABSTRACT Degradation of Paraquat compound in Gramoxone pesticide had been done by sonolysis, ozonolysis, and sonozolysis. Sonolysis methods were performed using an ultrasound VC-1, ozonolysis using a bio-ozone space age sterilizer, and sonozolysis by combining sonolysis and ozonolysis methods. The optimum condition for degradation of 4 mg/L paraquat by sonolysis was found at temperature 40±1°C. Percentage of degradation at optimum condition was 22.80% with 90 minutes treatment. Whereas, with using ozonolysis method percentage of degradation of paraquat 4 mg/L was 50.39% with 60 minutes treatment. The combination of sonolysis and ozonolysis method simultaneously, these so-called sonozolysis, for degradation of the same compound, extend the percentage of degradation to 45.87% with only 30 minutes treatment. Keywords: Paraquat, Sonolisis, Ozonolisis
PEMBUATAN LAPISAN TIPIS TiO2 -DOPED LOGAM M (M= Ni, Cu dan Zn) DENGAN METODA DIP-COATING DAN APLIKASI SIFAT KATALITIKNYA PADA PENJERNIHAN AIR RAWA GAMBUT Arief, Syukri; Alif, Admin; Willian, Nancy
Jurnal Riset Kimia Vol 2, No 1 (2008): September
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v2i1.111

Abstract

 ABSTRACT Preparation of TiO2-doped M (M = Ni, Zn and Cu) has been prepared on glass substrate using dip-coating technique. Titanium isopropoxide (TIP), Ni(OAct)2.4H2O, Zn(OAct)2.2H2O dan Cu(OAct)2 were used as starting materials and diethanolamine (DEA) as additive in isopropanol solution. Solutions were prepared by mixing of various concentration of metals (1, 3 and 5 mol %)  in 0.5 M TIP solution. Thin films were performed by immersion of glass substrate into solution by withdraw speed of 20 cm/min. Coated glass were dried at 100 – 110°C and heated at 500°C the process were repeated for several time. The product was characterized by XRD and showing TiO2 layer of anatase structure. EDX analysis has shown that thin films have found of Ti and doped-metal. Their crystallized sizes were calculated by Scherrer formula shown that it obtained in various in range of 12-21 nm. According to transformation effectively of titania doped M in peat swam water shown that catalytic activity 34.4 – 53.7% for the irradiation during 24 hours. Keywords : titania, thin films, photocatalytic properties
SINTESIS DAN KARAKTERISASI PARTIKEL NANOSPERIK TIO2 MELALUI METODE HIDROTERMAL GELOMBANG MIKRO Amir, Amelia; -, Emriadi; Arief, Syukri; Manseki, Kazuhiro; Sugiura, Takashi
Jurnal Riset Kimia Vol 7, No 2 (2014): March
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v7i2.166

Abstract

 ABSTRACTSimple synthesis of nanospherical TiO2 by microwave hydrothermal method has beeninvestigated. Titanium tetra isopropoxide (TTIP) and tetra methyl ammonium hydroxide(TMAOH) were used as precursor. The crystal phase and microstructure were characterized byX-Ray Diffraction (XRD) and transmission electron microscopy (TEM) including selected areadiffraction (SAED). The presence of intense peak in the XRD patterns confirmed to anatase andin good agreement with SAED patterns. Nanospherical of particles were clearly seen in theTEM image and the size of particles was approximately 4-5 nm.Keywords : microwave hydrothermal, colloidal titanates, structure directing agent,nanospherical TiO2
PEMAKAIAN CHELATING MONOLITH SEBAGAI SOLID PHASE MICROEXTRACTION (SPME) TRACE ELEMEN DI DALAM AIR Rahmi, Dwinna
Jurnal Riset Kimia Vol 3, No 1 (2009): September
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v3i1.51

Abstract

 ABSTRACT A syringe-based sample pretreatment tool, named herein “chelating monolith”, has been developed for simple and facile solid phase microextraction (SPME) of trace elements in natural waters. The monolith was directly prepared within the confines of a commercially available syringe filter tip by a two-step process: 1) in situ polymerization of glycidyl methacrylate (GMA) with ethylene glycol dimethacrylate (EDMA) and 2) subsequent modification with iminodiacetate (IDA) via ring opening reaction of epoxide. The composition of porogenic solvent was first optimized to make a rigid-porous material that has high permeability and ample surface area as much as possible. Then, the pH and concentration of the IDA modification solution were examined to obtain higher chelating capacity. The metal adsorption properties of the obtained chelating monolith were evaluated through an adsorption/desorption experiment. After optimization of some parameters such as sample solution pH, eluent concentration and the volume, good recoveries of more than 80% were obtained for 28 elements including REEs, Fe, Co, Ni, Cu, Zn, Ga, Pb and Th in a single extraction step. The proposed SPME method was validated through the analysis of river water certified reference material (CRM: JSAC 0301-1) Keywords: Solid phase microextraction; syringe filter; chelating monolith; iminodiacetate; ICP-MS
VALIDASI METODA PENENTUAN ANTIOKSIDAN TOTAL (DIHITUNG SEBAGAI ASAM SITRAT) DALAM SAMPEL JERUK SECARA SPEKTOFOTOMETRI DENGAN MENGGUNAKAN OKSIDATOR FeCl3 DAN PENGOMPLEKS ORTO-FENANTROLIN -, Yefrida; Ulfaningsih, Mega; Loekman, Umiati
Jurnal Riset Kimia Vol 7, No 2 (2014): March
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v7i2.187

Abstract

ABSTRACTAntioxidant is a compound that can be used to obstruct species oxygen reactive, speciesnitrogen, and other free radicals so it can be used degenerative illnesses inhibition. Citric acid isa natural antioxidant that can be found in some kind of oranges. There are some methode thatusually used to determination the antioxidant, such as CUPRAC, DPPH, and FRAP. Objectiveof this research is studied about alternative method to determine total antioxidant that is countedas citric acid by using FeCl3 as an oxidator and o-phenantroline as a complexant reagent. Instudied of appropriateness of this method, validation has been done with parameter linearity,LoD, LoQ, SDR, and recovery with samples orange, kaffir lime, and lime. Base on the research,the regression equation is Y = 0,066 + 117.35 X and R2 = 0.990 with value of LoD is1.15x10-3M and LoQ is 3.86x10-3 M. The value of SDR and recovery in samples orange, kaffir lime, andlime are 1.64%, 0.53% 2.14%, and 100.47%, 93.58%, 93.78%, respectively. Base on validationmethod data, can be concluded that this method appropriate to be used to determination of totalantioxidant for samples orange, kaffir lime, and lime.Keywords : Antioxidant, Validation Method, Spectrophotometry
AN IN-SYRINGE La CO-PRECIPITATION METHOD FOR PRE-CONCENTRATION OF OXO-ANIONS FORMING ELEMENTS IN SEAWATER FOLLOWED BY ICP-MS MEASUREMENT Rahmi, Dwinna; ZHU, Yanbei; Fujimori, Eiji; Hasegawa, Takuya; Umemura, Tomonari; Konagaya, Shigeji; Haraguchi, Hiroki
Jurnal Riset Kimia Vol 1, No 1 (2007): September
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v1i1.33

Abstract

Vol. 1 No. 1ABSTRACT A lanthanum (La) co-precipitation method was explored for pre-concentration of oxo-anion forming elements followed by measurement with Inductively Coupled Plasma Mass Spectrometry (ICP-MS).  The co-precipitation and subsequent washing and elution steps were performed in a 25 mL-volume syringe in order to save the sample consumption and to avoid the contamination from the experimental environment.  In the present work, various parameters such as the concentration of La added into the sample solution, the pH, aging time, and so on were optimized to obtain good recoveries and analytical detection limits for V, As, Se, Sb, and W.  Generally, in the co-precipitation method, high concentration of precipitant (in this case, La) causes a serious problem of signal memory effect in ICP-MS measurement. To reduce such memory effect, in the present experiment, high level of La was removed by passing the analyte solution (i.e., lanthanum hydroxide dissolved in 1 M HNO3) through a mini column packed with cation-exchange resins.  The method thus obtained was evaluated through the measurement of V, As, Se, Sb and W in seawater reference materials (CASS-4 and NASS-5). The recoveries exceeded 80%, and the observed values were in good agreement with the certified values. Thus, the present method was applied to the determination of trace elements in real seawater sample.    Keywords: Lanthanum, pre-concentration
MEKANISME INHIBISI ENZIM POLIFENOL OKSIDASE PADA SARI BUAH MARKISA DENGAN SISTEIN DAN ASAM ASKORBAT1 Mardiah, Elida
Jurnal Riset Kimia Vol 4, No 2 (2011): March
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v4i2.126

Abstract

 ABSTRACT The mechanism of polyphenol oxidase enzyme inhibition was studied by isolation of enzyme from the passion fruite juice (Passiflora Sp). The extracted enzyme polyphenol oxidase has an optimum activity at pH 5,6 and temperature of 300 C using a pirogalol substrate. The pattern of inhibition of the enzyme polifenol oxsidase studied using cysteine and ascorbic acid. Cystein of 10 mM consentration can inhibit the enzyme polyphenol oxidase activity as 97.25%, ascorbic acid with the same concentration can inhibit the enzyme polyphenol oxsidace 96.5%. The pattern of inhibition of cysteine is more likely to be competitive, while non-competitive with ascorbic acid. Keyword: polyphenol oxsidase, inhibition, cysteine, ascorbic acid
DEGRADASI SENYAWA 2,4 (DIKLOROFENOKSI) ASAM ASETAT DALAM PESTISIDA SIDAMIN 865 AS SECARA FOTOLISIS DENGAN PENAMBAHAN TiO2-ANATASE Hakim, Abinul; -, Safni; Suyani, Hamzar; Sakai, Tadao
Jurnal Riset Kimia Vol 3, No 1 (2009): September
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v3i1.20

Abstract

ABSTRACT Degradation of 2,4-Dichlorophenoxyacetic Acid (2,4-D) in Sidamin 865 AS pesticides had been carried out by photolysis with adding anatase-TiO2. Photolysis method were performed using an irradiation of UV-light at λ 365 nm, 10 W. The degradation of 20 mg/L 2,4-D without addition of anatase-TiO2 was 6.88% within 90 minutes treatment. Degradation of 20 mg/L 2,4-D by photolysis with addition of 0.1000 g anatase-TiO2, degradation was 31.55% within 90 minutes irradiation without stirring and it was 95.42% within 90 minutes irradiation with stirring. Keywords : photolysis, 2,4-dichlorophenoxyacetic acid, anatase-TiO2 
TRANSPOR IODIN MELALUI MEMBRAN KLOROFORM DENGAN TENIK MEMBRAN CAIR FASA RUAH -, Refinel; Kahar, Zaharasmi; -, Sukmawita
Jurnal Riset Kimia Vol 5, No 1 (2011): September
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v5i1.181

Abstract

 Vol 5 No 1ABSTRACT The transport of iodine through a bulk liquid membrane containing chloroform as the solvent and alkaline sodium sulfite solution as the receiving phase was studied .Iodine transport was performed by bulk liquid membrane technique consist of 10 mL I2/KI solution as feed phase, Na2SO3 (20 mL) and NaOH solution as receiving phase, and chloroform (30 mL) as membrane phase which was stirred 100 rpm. The presence of iodine both in feed and receiving phase then where determined by Spectrophotometer UV-Vis with λ max at 567 nm. The optimum conditions for iodine transport investigated from this work are 4x10-3 N, pH 4 in feed phase, pH 9 in receiving phase, I2 : KI ratio in feed phase (2 : 5), and a stirring duration is 180 minutes. As conclusion the bulk liquid membrane technique with Na2SO3 and NaOH as receiving and acception substances is potential for iodine transport resulting 78.6 % of iodin transport. Keywords: Iodine, transport, chloroform, bulk liquid membrane, Na2SO3, NaOH
STUDY ON ANTI-MICROBIAL PROPERTIES OF Enicosanthum membranifolium SINCLAIR AND Enicosanthum cupulare (KING) AIRY-SHAW Efdi, Mai; Koketsu, Mamoru; Watanabe, Kunitomo; -, Nurainas
Jurnal Riset Kimia Vol 3, No 1 (2009): September
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v3i1.75

Abstract

 ABSTRACT n-Hexane and ethyl acetate fractions of methanol extracts of two species of Annonaceae, Enicosanthum membranifolium Sinclair and Enicosanthum cupulare (King) Airy-Shaw, were screened for antimicrobial activity against eighteen bacterial strains using agar dilution method. The ethyl acetate fraction of the two Annonaceae plants showed higher antimicrobial activities than the n-hexane fraction. The extracts of the plants tested were significantly more active against gram-positive with minimum inhibitory concentration (MICs) ranging from 0.0625 to 4 mg/mL than against gram negative bacteria (MICs >4 mg/mL). Keywords: Antibacterial activity; Enicosanthum membranifolium Sinclair; Enicosanthum cupulare (King) Airy-Shaw

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