KOVALEN: Jurnal Riset Kimia
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.
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<![CDATA[PERSEN DEGRADASI EKSTRAK ETANOL KELOPAK BUNGA ROSELLA (Hibiscus sabdariffa L.) SELAMA PENYIMPANAN THE PERCENTAGE OF ETHANOL EXTRACTS OF ROSELLE PETALS (Hibiscus sabdariffa L.) DURING STORAGE ]]>
<![CDATA[firmasari firmasari]]>;
<![CDATA[Ni Ketut Sumarni]]>;
<![CDATA[Ruslan]]>;
<![CDATA[Hardi Ys]]>
<![CDATA[ KOVALEN: Jurnal Riset Kimia Vol. 5 No. 2 (2019): Edisi Agustus ]]>
Publisher : <![CDATA[Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University ]]>
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DOI: 10.22487/kovalen.2019.v5.i2.9970
<![CDATA[Ethanol extract of roselle petals (Hibiscus sabdariffa L.) is more stable in low pH than in high pH. The research aims to monitor and determine the effect of ratio content in ethanol extract of roselle petals (Hibiscus sabdariffa L.) in tomato sauce and the pH effect on the percentage of ethanol extract degradation during storage. Two independent variables implemented in this study, are ratio content of ethanol extract of roselle petals (Hibiscus sabdariffa L.) in tomato sauce and pH. Ethanol extract of roselle petals (Hibiscus sabdariffa L.) in tomato sauce with ratio content 0,5:1; 1:1; and 1:0 (w/w) and adjusted to pH 2, pH 3, pH 4, pH 5 and pH 6, respectively were investigated. The absorbance measurement of Ethanol extract of roselle petals (Hibiscus sabdariffa L.) in tomato sauce was depend on each treatment, then analyzed using completely randomized design. The percentage of ethanol extract of roselle petals (Hibiscus sabdariffa L.) degradation in tomato sauce decreased in ratio content 1:0 (w/w) at pH 2 with percentage content of degradation is 30.09%. Furthermore, after 10 days of storage, the highest percentage of ethanol extract of roselle petals (Hibiscus sabdariffa L.) in tomato sauce degradation is 93.33% with ratio content is 0.5:1 at pH 6 and the lowest is 30.09% with ratio content 1:0 at pH 2. Keywords: Roselle petals, Ethanol Extract, Tomato Sauce, Percentage of Degradation]]>
<![CDATA[KEMAMPUAN ADSORBSI ABU SEKAM PADI TERHADAP AIR DAN ASAM LEMAK BEBAS VIRGIN COCONUT OIL (VCO) DALAM KOLOM ADSORBSI ]]>
<![CDATA[Laras mariance sulo]]>;
<![CDATA[Khairuddin]]>;
<![CDATA[Ruslan]]>
<![CDATA[ KOVALEN: Jurnal Riset Kimia Vol. 5 No. 2 (2019): Edisi Agustus ]]>
Publisher : <![CDATA[Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University ]]>
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DOI: 10.22487/kovalen.2019.v5.i2.10115
<![CDATA[A research has been conducted on the adsorption ability of rice husk ash to water content and free fatty acid of virgin coconut oil (VCO) in the adsorption column. The objective of this research is to get the ratio of coarse VCO to rice husk ash adsorbent in the column that produces VCO with water content, free fatty acid that meets SNI and yields VCO yield not less than 80%. This study used a completely randomized factorial design (CRF design) with the effect of the amount of rice husk ash adsorbent (5g, 10g, 15g, 20g, 25g) in in columns 2.5 and 3 inches. The result of research on column 2.5 inch of the lowest water content (0.2%) was found on the weight of rice husk ash 25g and free fatty acid content on 25g ash husk ash was 0.1%. And at column 3.0 inch the lowest water content was found on 25g ash husk ash 0.1%, and the lowest free fatty acid content on ash weight of rice husk 25g was 0.2% and the best yield was 90%. Keywords: free fatty acid, rice husk ash adsorbent, moisture content, Virgin Coconut Oil]]>
<![CDATA[PENGARUH SUHU INKUBASI TERHADAP AKTIVITAS LIPASE DAUN PEPAYA (Carica papaya L) YANG DIAMOBILISASI DALAM PASIR LAUT ]]>
<![CDATA[Fisty Sumangkut]]>;
<![CDATA[Nurhaeni]]>;
<![CDATA[Ni Ketut Sumarni]]>;
<![CDATA[Erwin Abdul Rahim]]>
<![CDATA[ KOVALEN: Jurnal Riset Kimia Vol. 5 No. 2 (2019): Edisi Agustus ]]>
Publisher : <![CDATA[Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University ]]>
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DOI: 10.22487/kovalen.2019.v5.i2.10242
<![CDATA[The silica content in sea sand can be used to immobilize lipase from papaya leaf. Research on the influence of incubation temperature on sea sand immobilized lipase from papaya leaf (Carica papaya L) has been carried out. The aim of research is determining the influence of incubation temperature on sea sand immobilized lipase from papaya leaf (Carica papaya L). The method used in this study was a completely randomized design with temperature at 30, 40, 50, 60, 70°C. The results show that lipase from papaya leaf (Carica papaya L) had successfully immobilized in the sea sand and the optimum temperature stability of lipase immobilized in sea sand at 50°C with an activity is 53.000 µmol/g.jam Keywords : immobilized, lipase, papaya leaf, sea sand.]]>
<![CDATA[PENGGUNAAN KULIT UBI KAYU (Manihot utillisima Pohl) TERHADAP PENYERAPAN LOGAM Fe (III) PADA AIR PAYAU ]]>
<![CDATA[Delta Rinanda Duda]]>;
<![CDATA[Syaiful Bahri]]>;
<![CDATA[Jaya Hardi]]>;
<![CDATA[Nov Irmawati Inda]]>
<![CDATA[ KOVALEN: Jurnal Riset Kimia Vol. 5 No. 2 (2019): Edisi Agustus ]]>
Publisher : <![CDATA[Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University ]]>
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DOI: 10.22487/kovalen.2019.v5.i2.11469
<![CDATA[The absorption of Fe (III) metal in brackish water in the Balaroa Village, West Palu District using Cassava peels (Manihot utillisima Pohl) has been carried out. The aim of this study is determining the lifetime of cassava peels (Manihot utillisima Pohl) on the absorption of Fe (III) ions in brackish water. The research was conducted in a simple purification water system. Brackish water was flowed through the simple purification water system containing Cassava peels (Manihot utillisima Pohl) with a volume of brackish water is 10 liters per day (measured flow rate) and been analyzed every 2 days using UV-Vis spectrophotometry for less than 1 month. The results of the study show that cassava peel could be used as biosorbent to absorb and reduce level of Fe (III) ions in brackish water for 2.821 months. The concentration of Fe (III) ions in brackish water in Balaroa Village, West Palu District is 1.666 ppm. Keywords : Fe (III) Ion, Biosorbent, Cassava Peel]]>
<![CDATA[EKSTRAKSI DAN KARAKTERISASI KARAGENAN KASAR RUMPUT LAUT Eucheuma cottoni ]]>
<![CDATA[Asri jaya]]>;
<![CDATA[Ni Ketut Sumarni]]>;
<![CDATA[Ahmad Ridhay]]>
<![CDATA[ KOVALEN: Jurnal Riset Kimia Vol. 5 No. 2 (2019): Edisi Agustus ]]>
Publisher : <![CDATA[Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University ]]>
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DOI: 10.22487/kovalen.2019.v5.i2.11598
<![CDATA[Research on extraction and characterization of crude carrageenan from seaweed (eucheuma cottoni) has been carried out. The research aims to determine the optimum extraction time and temperature of crude carrageenan extract from seaweed (eucheuma cottoni). Crude Carrageenan was extracted from seaweed (eucheuma cottoni) by dissolving crushed seaweed in 8% KOH with variation of extraction times are 1 hour, 1.5 hours, 2 hours, 2.5 hours and 3 hours, and temperatures are 50, 70, 90, 110 and 130oC. The results were analyzed using a Completely Randomized Design (CRD). The results show that the optimum extraction time in producing the best quality of crude carrageenan is 2 hours at 50oC with percentage is 78.4%, viscosity is 9.155 cP, sulphate content is 3.102% and gel strength is 7 g. Keywords : eucheuma cottoni seaweed, crude carrageenan, characterization]]>
<![CDATA[POTENSI ANTIOKSIDAN METABOLIT SEKUNDER FRAKSI ETIL ASETAT DARI KULIT BATANG EBONI (Diospyros celebica Bakh.) ]]>
<![CDATA[Vivi Sasmita]]>;
<![CDATA[Ahmad Ridhay]]>;
<![CDATA[Hardi Ys]]>
<![CDATA[ KOVALEN: Jurnal Riset Kimia Vol. 5 No. 2 (2019): Edisi Agustus ]]>
Publisher : <![CDATA[Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University ]]>
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DOI: 10.22487/kovalen.2019.v5.i2.11642
<![CDATA[Research on the antioxidant potential of the secondary metabolite compound, ethyl acetate from ebony bark (Diospyros celebica Bakh.) has been conducted. This study aims to characterize and determine the antioxidant activity of secondary metabolites of ethyl acetate fraction from ebony bark. Ethyl acetate extract was fractionated using Liquid Vacum Chromatography (KVC) and Gravity Column Chromatography (KKG). The isolated compounds were characterized using UV-Vis and IR spectrophotometers. Data on maximum absorption of λmax 273 nm from UV-Vis analysis showed the presence of chromophore phenol. IR spectral data showed several specific peaks, among others, at wave number (ʋ) of 3425.58 cm-1 indicating the presence of –OH group, C-H aliphatic bond at ʋ of 2924.09 cm-1 and 2854.65 cm-1, and the peak at ʋ of 1604.77 -1465.90 cm-1 and 3078.39 cm-1 indicated the aromatic group, reinforcing the assumption that the isolates produced were phenolic compounds. IC50 value of 75.47 µg/mL from antioxidant activity testing showed that the isolates obtained were antioxidant compounds with strong antioxidant categories. Keywords: antioxidant, Diospyros, ebony, phenolic, isolation]]>
<![CDATA[PEMBUATAN Carboxymethyl cellulose (CMC) DARI PELEPAH NANAS (Ananas cosmosus Merr.) ]]>
<![CDATA[Ripdayana Ripdayana]]>;
<![CDATA[Ahmad Ridhay]]>;
<![CDATA[Erwin Abdul Rahim]]>
<![CDATA[ KOVALEN: Jurnal Riset Kimia Vol. 5 No. 2 (2019): Edisi Agustus ]]>
Publisher : <![CDATA[Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University ]]>
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DOI: 10.22487/kovalen.2019.v5.i2.11654
<![CDATA[A research about production of Carboxymethyl cellulose (CMC) from pineapple midrib (Ananas cosmosus Merr.) has been conducted. This research aims to determine the best cellulose ratio with sodium monochloro acetate and the best reaction time to the substitution degree of carboxymethyl cellulose from pineapple midrib fibers. This study used a Completely Randomized Design method with two independent variables, i.e. variations in the weight of sodium monochloroacetate (2.5 grams, 3 grams, 3.5 grams, 4 grams, and 4.5 grams) and variations in reaction time (1 hour, 2 hours, 3 hours, 4 hours , and 5 hours), each treatment was done duplo using 20 treatment units. The result of the study showed that the best ratio of sodium monochloroacetate to cellulose which produced carboxymethyl cellulose from pineapple midribs was 2.5: 2.5 with substitution degree value of 1.93 and optimum reaction time which produced carboxymethyl cellulose from pineapple midribs was 1 hour with substitution degree of 2.38. Keywords: Carboxymethyl cellulose, Pineapple midrib]]>
<![CDATA[AKTIVITAS ANTIBAKTERI FRAKSI n-HEKSAN, KLOROFORM, ETIL ASETAT BUNGA KAMBOJA (Plumeria alba) TERHADAP BAKTERI Staphylococcus aureus DAN Salmonella typhi ]]>
<![CDATA[ni nyoman rupiniasih]]>;
<![CDATA[Indriani]]>;
<![CDATA[Syamsuddin]]>;
<![CDATA[Abdul Rahman Razak]]>
<![CDATA[ KOVALEN: Jurnal Riset Kimia Vol. 5 No. 2 (2019): Edisi Agustus ]]>
Publisher : <![CDATA[Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University ]]>
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DOI: 10.22487/kovalen.2019.v5.i2.12572
<![CDATA[Tests on the inhibition extract of n-hexane fraction, extract of chloroform fraction and extract of ethyl acetate fraction of frangipani flower (Plumeria alba) on Staphylococcus aureus and Salmonella typhi has been done. This study aims to determine the activity of frangipani flower extract on the growth of S. aureus and S. typhi bacteria. Frangipani flowers was macerated using methanol solvents. The obtained methanol extract was partitioned with n-hexane, chloroform and ethyl acetate solvents, respectively. The three extracts were tested for antibacterial activity at a concentration of 10% using the diffusion well method. The test results showed that the n-hexane, chloroform and ethyl acetate fractions showed an inhibition zone of 9.77 mm, 20.89 mm and 19.44 against S. aureus whereas S. typhi showed an inhibition zone of 15.86 mm, 27.69 mm and 21.74 mm. Keywords: Antibacterial, extract of frangipani flower, Staphylococcus aureus, Salmonella typhi.]]>
<![CDATA[STUDI ADSORPSI LOGAM Pb PADA TANAH TERCEMAR ABU TERBANG (Fly Ash) DENGAN MENGUNAKAN TANAMAN KANGKUNG DARAT (Ipomoea reptans Poir) ]]>
<![CDATA[Yul Uca Sali Putri]]>;
<![CDATA[Khairuddin]]>;
<![CDATA[Husain Sosidi]]>;
<![CDATA[Dwi Juli Pusptasari]]>
<![CDATA[ KOVALEN: Jurnal Riset Kimia Vol. 5 No. 2 (2019): Edisi Agustus ]]>
Publisher : <![CDATA[Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University ]]>
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DOI: 10.22487/kovalen.2019.v5.i2.12651
<![CDATA[Pb metal adsorption studies on land water spinach (Ipomoem reptans poir) have been carried out. The method of analysis was carried out using a completely randomized design with two independent variables, i.e amount of Pb metal concentration adsorb on the roots of land spinach and the lifetime of the land spinach roots. The results show that the amount of Pb metal adsorp on the land spinach roots with variations in the age of 2-5 consecutive weeks was 0,023 µg/g; 0,03 µg/g; 0,084 µg/g; 0,099 µg/g, respectively. The results of both statistical tests, F test and LSD test, show that there was a significant difference in the concentration of Pb in each age of harvest, which in the fifth week showed the highest Pb level. BCF test results show that Pb metal adsorption takes piace with a phytoextraction mechanism. Keywords: Absorption, Lead Metal, Land Weter Spinach, Pb Levels, Length Of Planting Time]]>
<![CDATA[ANALISIS KLT BIOAUTOGRAFI EKSTRAK KULIT BATANG TANAMAN KAYU JAWA (Lannea coromandelica) TERHADAP BAKTERI Staphylococcus aureus DAN Shigella dysentriae ]]>
<![CDATA[yumita yumita]]>;
<![CDATA[Abdul Rahman Razak]]>;
<![CDATA[Indriani]]>;
<![CDATA[Syaiful Bahri]]>
<![CDATA[ KOVALEN: Jurnal Riset Kimia Vol. 5 No. 2 (2019): Edisi Agustus ]]>
Publisher : <![CDATA[Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University ]]>
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DOI: 10.22487/kovalen.2019.v5.i2.12786
<![CDATA[Java wood plants (Lannea coromandelica) is a traditional medicinal plant which is still often used by people to treat internal and external wounds. The study aims to determine the effect of solvent polarity in Javanese stem bark extract on Staphylococcus aureus and Shigella dysenteriae, and to identify the compound groups which had an antibacterial activity against Staphylococcus aureus and Shigella dysenteriae with KLT-Bioautography analysis. The results show that the n-hexane extract of Javanese bark is not showing an antibacterial activity against Staphylococcus aureus and Shigella dysenteriae, whereas the ethyl acetate extract and methanol of Javanese bark show an antibacterial activity against Staphylococcus aureus and Shigella dysenteriae. The results of the TLC-Bioautography test show negative results for Staphylococcus aureus and Shigella dysenteriae. Keywords: Lannea coromandelica, antibacterial, Staphylococcus aureus, Shigella dysentriae, KLT-Bioautografi]]>
