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Jaya Hardi
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KOVALEN: Jurnal Riset Kimia
Published by Universitas Tadulako
ISSN : -     EISSN : 24775398     DOI : https://doi.org/10.22487/kovalen
Core Subject : Science, Engineering,
Chemical Engineering, Chemistry & Bioengineering Chemistry
KOVALEN: Jurnal Riset Kimia is a peer-reviewed journal of chemistry published by the Tadulako University, Indonesia. This journal concern with publishing the original research articles, review articles, and the current issues related to chemistry. Publishing frequency 3 issues per year, in April, August, and December.
Arjuna Subject : Kimia(semua kategori) - Kimia (Lain-Lain)
Articles 12 Documents
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Search results for , issue "Vol. 3 No. 3 (2017): Edisi Desember" : 12 Documents clear
STUDI KINETIKA DAN ISOTERM ADSORPSI TIMBAL(II) PADA KULIT JENGKOL (Pithecellobium jiringa) TERAKTIVASI GATUT ARI WARDANI; WINDA TRISNA WULANDARI
KOVALEN: Jurnal Riset Kimia Vol. 3 No. 3 (2017): Edisi Desember
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

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Abstract

Penggunaan limbah kulit jengkol untuk mengadsorpsi ion timbal(II) telah berhasil dilakukan. Kulit jengkol yang digunakan merupakan limbah dari salah satu pasar tradisional di Kota Tasikmalaya.  Kulit jengkol diaktivasi terlebih dahulu menggunakan asam nitrat sebelum digunakan sebagai adsorben. Waktu optimum yang dibutuhkan kulit jengkol untuk mengadsorpsi ion timbal(II) adalah 30 menit dengan persen ion teradsorpsi sebesar 60,6936%. Kinetika adsorpsi timbal(II) pada kulit jengkol mengikuti model kinetika pseudo dua Ho dengan nilai R2 sebesar 0,9954 dan nilai k sebesar 1,9843 menit-1. Isoterm adsorpsi dari timbal(II) pada kulit jengkol mengikuti model adsorpsi Freunlich dengan nilai R2 sebesar 0,9797 dan kapasitas adsorpsi sebanyak 0,5537 mg/gram.
SINTESIS HIDROKSIAPATIT DARI TULANG SAPI DENGAN METODE BASAH PADA BERBAGAI WAKTU PENGADUKAN DAN SUHU SINTERING Reflin Yuliana; Erwin Abdul Rahim; Jaya Hardi
KOVALEN: Jurnal Riset Kimia Vol. 3 No. 3 (2017): Edisi Desember
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

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Abstract

Synthesis of hydroxyapatite (HAp) can be obtained from a reaction between calcium of cow bones and phosphate under wet method. Completely Random Design (CRD) was used in this research with three levels of stirring time and four levels of sintering temperature i.e. 60, 90, 120 minutes and 800oC, 850oC, 900oC, 950oC, respectively. The result showed that synthesis reaction at the sintering temperature of 850oC for 120 minutes were the best conditions to produce HAp. The yield of HAp product in those conditions was 48,5%. XRD spectrum of HAp had the highest intensity of 1000 at a 2Ɵ angel of 31.78o.Keywords: Hydroxyapatite, Stirring Time, Sintering Temperature, Cow Bone
PENGARUH EKSTRAK METANOL DAUN PEPAYA (Carica papaya L.) TERHADAP AKTIVITAS ENZIM LIPASE Nurhaeni Nurhaeni; Ahmad Ridhay; Magfira Magfira
KOVALEN: Jurnal Riset Kimia Vol. 3 No. 3 (2017): Edisi Desember
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

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Abstract

Has conducted research on the effects of methanol extract of leaves papaya (Carica papaya L.) Against Lipase Enzyme Activity. This study aimed to obtain information in a methanol extract inhibits lipase activity. The method used is Complete Random Design (RAL), with goal attainment is done by determining the incubation time lipase enzyme, pH optimum lipase enzyme, and maximum substrate concentration lipase enzyme. And determining the effect of the methanol extract to inhibit the lipase enzyme activity. The results showed that the best incubation time of lipase obtained by time of 120 minutes, the optimum pH 7 and the maximum substrate concentration of 4%. With the highest activity were obtained 16.94 mol /ml.menit, 13.33 mol / ml.menit, and 12.89 mol / ml.menit. The methanol extract of papaya leaves can inhibit the lipase enzyme activity the best concentration of 2% with the acquisition activity of 3.67 mol/ml.menit.Keyword: papaya, lipase, incubation time, optimum pH, substrate concentration.
PENENTUAN MASA KADALUARSA LIKOPEN DARI BUAH TOMAT (Lycopersicum pyriforme) TERCAMPUR MALTODEKSTRIN DALAM KEMASAN KAPSUL Kostriana Daniel; Mappiratu Mappiratu; Ni Ketut Sumarni
KOVALEN: Jurnal Riset Kimia Vol. 3 No. 3 (2017): Edisi Desember
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

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Abstract

The investigation about the determination of the expired time of lycopene made from tomato (Lycopersicum pyriform) which was mixed with maltodextrin in capsule packaged has been done. The aim of the research is to determine the ratio of lycopene extract to maltodextrin for yielding lycopene with the highest purity degree and to determine the expired time. The applied ratio of lycopene to maltodextrin were 5:10, 7.5:10, 10:10, 10:7.5, 10:5 (w/w). Those samples were stored at room temperature for 10 weeks. Spektrofotometri UV-VIS was used to analyze the samples. The results showed that the highest purity degree was reached at the ratio of 10:10 (39.56%). The best expired time at the ratio of 5:10 was reached at 12.93 weeks.Keywords: Tomato, lycopene, lycopene mixed maltodextrin, purity degree, expired
EKSTRAKSI GLUKOMANAN DARI UMBI PORANG (Amorphophallus paeniifolius (Dennst.) Nicolson) Elis Setiawati; Syaiful Bahri; Abd. Rahman Razak
KOVALEN: Jurnal Riset Kimia Vol. 3 No. 3 (2017): Edisi Desember
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

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Abstract

This study aims to determine the temperature and the ratio of tuber flour porang using isopropyl alcohol precipitator in producing glucomannan extract with the highest yield. The study was designed using completely randomized design (CRD), which consists of two factors: the temperature of the extraction consists of seven levels (45, 55, 65, 75, 85, 95, and 105 0C) and the ratio of tuber flour porang by precipitating isopropyl alcohol consists of 5 level (1: 7, 1:10, 1:13, 1:16, and 1:19 (w/v). each done in duplicate. parameters measured were yield characteristics glucomannan and the results showed that the extraction of the best glucomannan obtained at a temperature of 95 0C with a yield of 41.614%. the ratio of starch tuber porang best isopropyl alcohol is 1:19 (w/v) with a yield of 45.167% glucomannan. Test characteristics of glucomannan gained 6.6% moisture content, the ash content of 0.8%, and a molecular weight of 0.726 x 104 g/mol.Keywords: porang tuber flour, shaking temperature, glucomannan.
UJI AKTIVITAS ANTIBAKTERI EKSTRAK DAUN TANAMAN JOHAR (Cassia siamea Lamk.) DARI BEBERAPA TINGKAT KEPOLARAN PELARUT Fitriah Fitriah; Mappiratu Mappiratu; Prismawiryanti Prismawiryanti
KOVALEN: Jurnal Riset Kimia Vol. 3 No. 3 (2017): Edisi Desember
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

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Abstract

A research about antibacterial activity test of johar plant leaf extract (Cassia siamea Lamk.) using several levels of solvent polarity has been implemented. This study aims to determine whether the antibacterial compounds in the leaves is polar, non-polar or semi-polar, and to determine the highest inhibition level of johar leaf extract on both the gram-negative bacteria (Escherichia coli and Shigella dysenteriae) and gram-positive (Staphylococcus aureus and Micrococcus luteus). The maceration method was used in this research with 3 levels of solvent polarity namely non-polar, semi-polar and polar. The bacterial activity test was done with diffusion method. The results showed that the johar leaf contains antibacterial compounds which are polar and semi-polar. The highest inhibition level was obtained at johar leaf ethanol extract for Staphylococcus aureus, Escherichia coli, Micrococcus luteu and Shigella dysentriae of 14.9, 12.9, 12, and 7.2 mm, respectively.Keywords: Antibacterial, Inhibition Level, Johar Leaf Extract
ANALISIS KADAR TOTAL METABOLIT SEKUNDER EKSTRAK ETANOL DAUN TAMOENJU (Hibiscus surattensis L.) Astrid Natalia Alasa; Syariful Anam; Jamaluddin Jamaluddin
KOVALEN: Jurnal Riset Kimia Vol. 3 No. 3 (2017): Edisi Desember
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

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Abstract

Tamoenju (Hibiscus surattensis L.) leaves are included in the malvaceae family which grows in the plateau and are known to have the antidiabetic activity that the standardization of the extract is needed to be conducted. The research aimed to discover the total level of secondary metabolites from ethanol extract. The extraction of Tamoenju leaves through maceration method with 96% ethanol was done to obtain the filtrate. The filtrate obtained was concentrated by using rotary evaporator at 40°C until the concentrated extract was obtained. The extract gained was then tested in a qualitative way with Alkaloid, Flavonoid, Saponin, and Tannin tests by using the suitable reagent for the test parameters. While in the quantitative test the method used was Gravimetric analysis on alkaloid and Saponin compounds, Permanganometry on Tannin compound, and UV-Visible Spectrophotometry on Flavonoid. The qualitative test results reveal that Tamoenju is positive for containing Alkaloid which was characterized by the presence of orange sediment, Flavonoid was characterized by the orange formation, Tannin was characterized by the dark blue and Saponin was characterized by the stable foam. The quantitative test results are Alkaloid by 305.181 g/g, Saponin by 371.112 g/g, Tannin by 55.417 g/g and Flavonoid by 14.999 mg/100 g.Keywords: Hibiscus surattensis L. , secondary metabolites, standardization
PRODUKSI ENZIM LIPASE DARI Aspergillus niger ISOLAT KAPANG KOPRA DENGAN MENGGUNAKAN MEDIUM KELAPA PARUT Indah Indah; Mappiratu Mappiratu; Musafira Musafira
KOVALEN: Jurnal Riset Kimia Vol. 3 No. 3 (2017): Edisi Desember
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

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Abstract

The investigation about the lipase enzyme production from Aspergillus niger using grated coconut as a medium has been done. The aim of the study is to determine the best incubation time, pH and water content which produced lipase enzyme with high activity. Randomized Block Design (RBD) with 2 factorial pattern (incubation time and pH of the medium) was used in this research. Each factor consists of three levels and it was done in the triple. The level of incubation time and of pH were 48, 60, 72 hours and pH 5, 6, and 7, respectively. The observed parameter was the obtained lipase enzyme activity. The result showed that the highest activity was achieved at pH 7 for 48 hours of incubation time with 45% of water content. The amount of lipase enzyme activity was 1.70 µmol/ml.minutes.Keywords: mold coconut, Aspergillus niger, lipase
KAJIAN EKSTRAK ETANOL BUNGA BOGENVIL (Bougenvillea spectabillis Willd) SEBAGAI BIOINDIKATOR ASAM BASA Nurhaeni Nurhaeni; Fitri A Bande; Rismawaty Sikanna
KOVALEN: Jurnal Riset Kimia Vol. 3 No. 3 (2017): Edisi Desember
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

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Abstract

Studies of ethanol extract of bougainvillea flowers (Bougenvillea spectabillis Willd) as bioindicators of the acid-base has been done. The aims to determine the content of chemical compounds contained in extracts of bougainvillea flowers and bougainvillea flower extract pH stretch. Achievement of the objectives has done through the test of ethanol extract of bougainvillea identification of compounds and the determination of the acid-base stretch of pH indicator is. The obtained results showed that bogenvil ethanol extract containing flavonoids with 401 nm absorption and provided a color change in the acid and alkaline condition the color is yellow. The appropriate acid-base titration is used as bioindicators of a strong acid titration with a strong base, weak acid with a strong base and a weak base with a strong acid.Keywords: Flowers bougainvillea, indicators, bases acid titration
PENENTUAN EFISIENSI DYE SENSITIZED SOLAR CELL (DSSC) MENGGUNAKAN EKSTRAK BUAH KAKTUS (Opuntia elatior Mill.) Christianto Pasunu; Ruslan Ruslan; Hardi Ys.
KOVALEN: Jurnal Riset Kimia Vol. 3 No. 3 (2017): Edisi Desember
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

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Abstract

Dye-Sensitized Solar Cells (DSSC) research by using cactus fruit extract (Opuntia elatior Mill.) has been done. The objectives of the research are to determine the highest efficiency of submersion time and Dye pH treatments of cactus fruit extract (Opuntia elatior Mill.). This research was used a Complete Random Design (CRD) method whereas the submersion time of the worked electrode on five extents of treatments are 6,12,18, 24, 30 hours and Dye pH on four extents of treatments are 1, 3, 5, and 7. The result showed that the optimum time at 12 hours with the Dye pH at 3 has resulted in the highest efficiency of 0.105. Keywords: Cactus fruit extract, Opuntia elatior Mill, efficiency, DSSC.

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