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Determination Kinetic Parameters of Endo-β-1,4-D-Xylanase from Abdomenal Termites with Xylan Oat and Birchwood Istri Ratnadewi, Anak Agung; Linda Faiqotul Himmah; Tri Mulyono; Wuryanti Handayani; NG. Krishnabudi; Sudarko
Indonesian Chimica Letters Vol. 1 No. 1 (2022)
Publisher : Department of Chemistry, Faculty of Mathematics and Natural Sciences, University of Jember

Parameters kinetic (KM, VMax, and kCat) endo-β-1,4-D-xylanase under optimum conditions with oat spelt xylan and birchwood substrate have been investigated in this study. Hydrolysis of endo-β-1,4-D-xylanase using variation of substrate concentration (b/v) ranging from 0.2 to 1.2%. Variation of incubation time is up to 20 hours with 4 hours interval at the optimum temperature of the enzyme, 40°C. The results obtained from this study were the KM of endo-β-1,4-D-xylanase for oat spelt xylan and birchwood were 4.10 mg/ml and 0.681 mg/ml, respectively. VMax values, and kCat for oat spelt xylan substrate of 0.28 mg/ml.jam and 1.7 x 10-3 s-1. While VMax, and kCat for birchwood substrate that is 0.117 mg/U/jam and 7 x 10-4 s-1. From the results of this study we found that endo-β-1,4-D-xylanase can hydrolaze substrates which have differences solubility.

Determination of Zone Degradation for Sulfide (S2-) and Ammonia (NH3) in the Leachate from TPA Pakusari (Pakusari Landfill), Jember, Using Spectrophotometric Method Wijayanti, Chatarina; Siswoyo, Siswoyo; Mintadi, Mukh.; Maulidah Muflihah, Yeni
Indonesian Chimica Letters Vol. 1 No. 1 (2022)
Publisher : Department of Chemistry, Faculty of Mathematics and Natural Sciences, University of Jember

Leachate as a result from waste decomposition at landfills potentially contain toxic materials, including metals and organic matters. This leachate produces several environmental issues, including groundwater and surface water resources contamination. The landfill leachate can penetrate to the soil, blend with the soil water, flow to the soil surface, and then disembogue at the river channel. The contamination processes will vary depending on the contaminating substances and their degradation zone. Our study focused on analyzing sulfide and ammonia in the leachate. The sulfide and ammonia degradation zone have been determined by measuring the concentration of sulfide and ammonia using Spectro quant NOVA 60. The degradation zone determination ranged from the distances: 0 m, 50 m, 100 m, 150 m, and 200 m direct to the north, south, and west, and at distances of 0 m and 400 m in the east direction. The range of degradation zone based on the concentration of sulfide, ammonia, and DO (dissolved oxygen) was in a range between 150 m and 200 m from the leachate water reservoir located at TPA Pakusari (Pakusari Landfill) Jember.

Synthesis of Zeolite Y from Lapindo Mud with the Comparative Variation of the Weight of NaOH/Mud and Molar SiO2/Al2O3 Andarini, Novita; Haryati, Tanti; Suwardiyanto, Suwardiyanto; Sulistiyo, Yudi Aris
Indonesian Chimica Letters Vol. 1 No. 1 (2022)
Publisher : Department of Chemistry, Faculty of Mathematics and Natural Sciences, University of Jember

Lapindo mud is a waste that can be used as a zeolite formation material. Zeolite is a mineral there are silica and alumina. The zeolite synthesized was the zeolite Y. The synthesis of zeolite Y is carried out the melting method followed by hydrothermal process. The ratio of NaOH/sludge weight varied the weight of NaOH added to the sludge weight which was made constant, there were 1.1 gram of NaOH/1 gram of sludge; 1.3 gram of NaOH/1 gram of sludge; 1.5 gram of NaOH/1 gram of sludge; and 1.7 gram of NaOH/ 1 gram of sludge. The sludge was pretreated using HCl in the leaching process and NaOH for smelting. The melted sludge from the four variations was characterized using XRF. The results of characterization are used as the basis for determining the mass of SiO2 and NaOH that need to be added in the synthesis. The melted sludge was added with water, SiO2, and NaOH and cured for 48 hours at room temperature. The mixture that has been brooded is then filtered, the result of the filtering is the filtrate of sodium silicate and sodium aluminate solution. The filtrate was hydrothermal 100-105 °C for 24 hours. The resulting crystals were filtered and neutralized using aquademine. The resulting synthetic zeolite was white, then characterization was carried out using XRF and XRD. The characterization results on the variation of NaOH/sludge weight ratio could be seen from the XRF results. Zeolite Y varies the weight ratio of NaOH/sludge based on the character of the best zeolite produced at a weight ratio of NaOH/sludge 1.5.

Effect of pH in Coagulation Bath on Polysulfone-based Membrane Formation and Its Performance Characteristics Dwi Jayanti, Denik; Asnawati, Asnawati; Indarti, Dwi; S. Purwo Handoko, Donatus; Piluharto, Bambang
Indonesian Chimica Letters Vol. 1 No. 1 (2022)
Publisher : Department of Chemistry, Faculty of Mathematics and Natural Sciences, University of Jember

One of the factors that determine the formation of the membrane is the solution in the coagulation bath (non-solvent). In this study, the effect of pH treatment on the coagulation bath solution on membrane formation and its effect on membrane performance will be studied. The pH of the coagulation bath used was pH 1, 6.8 and 12. As the results, physically the three pH treatments produced the same white (opaque) membrane. Through morphological analysis, it appears that the three pH treatments produced an asymmetric membrane consisting of a top layer and a sublayer. The surface of the membrane with pH 1 treatment showed a denser surface than the pH 6.8 and pH 12 treatments. The results of the membrane performance characterization showed that the membrane permeability coefficient of the membrane with pH treatment was in the following order pH 1 < pH 12 < pH 6.8. While the value of the rejection coefficient showed that the membrane treated at pH 1 did not detect rejection because there was no permeate coming out, while at the treatment at pH 6.8 and 12, the rejection coefficient values were 74% and 76%, respectively.

Hydrogel Composite Based On Arrowroot Starch-G-Poly (Acrylamide-Co-Acrylic Acid)/Zeolite as Matrix of Controlled Release Urea Fertilizer Sjaifullah, Achmad; Winata, I Nyoman Adi; Suhardiman, Ahmad
Indonesian Chimica Letters Vol. 1 No. 1 (2022)
Publisher : Department of Chemistry, Faculty of Mathematics and Natural Sciences, University of Jember

Agricultural yields can be increased through fertilization. Conventional fertilization by spreading fertilizer on agricultural land is very ineffective. As much as 40-70% of the nitrogen from urea given through conventional fertilization will be leaching. This problem can be overcome by implementing a new fertilization system, namely by applying controlled fertilizer release technology or Control Release Fertilizer (CRF). The CRF system is made by loading or mixing urea fertilizer at the time of synthesis of a composite based on Arrowroot Starch-g-poly (acrylamide-co-acrylic acid)/zeolite. Fertilizer will come off gradually during fertilizing the land. Synthesis of starch-based hydrogel composite Arrowroot Starch-g-poly (acrylamide-co-acrylic acid)/zeolite loaded or mixed with urea fertilizer, has been successfully carried out. The composite's structure characterized by IR spectroscopy and its ability as CRF has also been tested through swelling and urea release tests in distilled water, phosphate buffer pH 5, pH 7 and pH 9. The results show that the swelling capacity and urea release in distilled water > Buffer pH 7 > pH 9 > pH 5. The welling degree in distilled water, Buffer pH 5, pH 7 and pH 9 is 39.078; 18,719; 36,296 and 33,510 g.g-1 respectively and the release of urea is 2,129; 1,829; 2,110; and 2,091 mg.mL-1 respectively and they showed significant differences.

Effect of Zeolite Concentration on Hydrogel Characteristics of Arrowroot-Based Starch-G-Poly(Acrylic Acid)/Zeolite Composite Sjaifullah, Achmad; Saputra, Beny Akhmat; Adiwinata, I Nyoman; Santoso, Agung Budi; Busroni; Reza, Muhammad
Indonesian Chimica Letters Vol. 1 No. 2 (2022)
Publisher : Department of Chemistry, Faculty of Mathematics and Natural Sciences, University of Jember

This study aims to synthesize a hydrogel zeolite composite of arrowroot starch graft copolymerized with acrylic acid through a radical polymerization reaction in a water. Various scenarios were tested using different natural zeolite concentration to determine the impact on swelling/water absorption of the composite. The resulting product was a solid gel-the test results showed that the swelling increased as the ratio of starch to acrylic acid decreased. Increased starch concentrations generally lead to decreased water absorption (swelling capacity). Adding a zeolite improved swelling to some extent and the optimum zeolite concentration was 60%. The increased concentration of zeolite also hardened the hydrogel composite. The highest swelling in the hydrogel composite of starch-g-poly(acrylic acid)/zeolite 60% is 1056.25 g.g-1. FTIR analysis of functional groups was conducted to determine differences in the IR spectra of arrowroot starch, acrylic acid, hydrogels, zeolites, and composite hydrogel. Si-O signal appearing on the IR spectra of hydrogel composite with wave number 1030 cm-1 indicates that composite hydrogel with zeolite was synthesized

The Permeation of High Concentration Hydrogen Sulfide (H2S) Gas Using PTFE (Polytetrafluoroethylene) and PVDF (Polyvinylidene Fluoride) membranes Asnawati, Asnawati; Diah Ayu Nur Sholehah; Dwi Indarti; Tri Mulyono; Bambang Piluharto; Muflihah, Yeni Maulidah
Indonesian Chimica Letters Vol. 1 No. 2 (2022)
Publisher : Department of Chemistry, Faculty of Mathematics and Natural Sciences, University of Jember

Hydrogen sulfide (H2S) is a toxic, corrosive, and flammable gas. The presence of H2S gas can be reduced by a permeation method using PTFE (Polytetrafluoroethylene) membranes and PVDF (polyvinylidene fluoride) membranes. This H2S gas passed through the membrane and was then captured by the SAOB (Sulfide Anhydride Oxidant Buffer) in S2- species form. A visible spectrophotometer was applied for the analysis of passed H2S gas. Using a PTFE membrane, the optimum flow rate was obtained at 14.71 mL/min, with a mass flux of 0.825 kg/m2.hour, permeability coefficient of 0.696 kg/m2.hour.bar, and percent removal of H2S gas was 88.14%. The optimum flow rate for the SAOB was obtained at a rate of 0.30 mL/min with a mass flux of 0.843 kg/m2.hour and a percent removal of H2S gas of 89.98%. Based on the results obtained on the PVDF membrane, the mass flux produced in the optimization of H2S gas is 0.742 kg/cm2.hour, and the optimization of the SAOB solution is 0.754 kg/cm2.hour. The resulting permeability coefficient value is 0.741 kg/cm2.hour. The results indicate that this study can remove H2S gas at the optimum H2S gas flow rate of 4.76 mL/minute of 94.89% and the optimum SAOB flow rate of 0.3 mL/minute of 95.66%

Optimization of Centrifugation Speed and pH in Extraction of Uricase Enzyme from Goat Liver Handayani, Wuryanti; Esti Utarti; Riki Juni Krismiadi; AA. Istri Ratnadewi
Indonesian Chimica Letters Vol. 1 No. 2 (2022)
Publisher : Department of Chemistry, Faculty of Mathematics and Natural Sciences, University of Jember

The human body does not have an enzyme that can break down uric acid, so the accumulation of uric acid can cause disease. This problem can be overcome by uricolytic therapy by utilizing the activity of the uricase enzyme. In this study, the uricase enzyme was extracted from goat liver by optimizing the centrifugation speed and the extraction pH. The purpose of the optimization is to get maximum uricase activity. Uricase extraction to optimize centrifugation speed using borate buffer pH 8.5 then centrifuged at 7.000; 9.000; 11.000; 13.000 and 15.000 rpm with a temperature of 4oC. Furthermore, pH optimization was carried out using pH buffers 6, 7, 8, 9, 10 and 11 by centrifuging the optimum speed obtained. The crude extract obtained was further tested for its enzyme activity . The results showed that the highest uricase activity was achieved if the extraction was carried out at pH 8 using centrifugation at an optimum speed of 13,000 rpm. The higher uricase activity indicates that the extracted uricase concentration is increasing.

Solid State Transformation of TiO2 Rutile and its Photocatalytic Activity Sulistiyo, Yudi Aris; Kamila, Wilda; Andarini, Novita; Suwardiyanto, Suwardiyanto; Sunnardianto, Gagus Ketut; Haryati, Tanti
Indonesian Chimica Letters Vol. 1 No. 2 (2022)
Publisher : Department of Chemistry, Faculty of Mathematics and Natural Sciences, University of Jember

Transformation phase TiO2 Rutile was conducted to improve the photocatalytic activity. This study evaluated the transformation phase of TiO2 rutil using solid state rection method and tested for gycerol conversion reaction. a semiconductor material that can be applied for glycerol conversion. The solid state reaction using a mixture of TiO2 Rutile and sodium titanate in mole rasio 1:4 that was heated in 750 oC. XRD analysis evaluated the transformation phase of the solid state reaction product, while band gap energi was calculated following UV-Vis diffuse reflectance data. The photoactivity of glycerol was exposed by UV-Light in various time (5, 10, 15 h) that of the liquid product was analyzed by gas chromatography. Solid state reaction transformed TiO2 rutil to polymorph structure (TiO2 rutile, TiO2 anatase, and sodium titanate Na4O12Ti5). The band gap energy of the product was 3.2 eV. The optimum photocatalytic activity was 62.7% in glycerol concentration 0.25 M for 15 h time reaction.

Identification and determination α and β-acids from Columbus hops using Reverse Phase High Pressure Liquid Chromatography Zulfikar, Z.; Antje, Labes
Indonesian Chimica Letters Vol. 1 No. 2 (2022)
Publisher : Department of Chemistry, Faculty of Mathematics and Natural Sciences, University of Jember

The present study has demonstrated the HPLC method for identification and determination a and b-acids in Columbus hops. the measurement conditions has been set up included the use of Reverse phase C18 column Chromolith, gradient elution with methanol (A) and Acetonitril acidified with phosphate buffer at pH 2.8. While the flow rate has been applied of 0.8 mL/min, and it is run for 25 minutes. The separation of standard and sample has been monitored using UV variable detector in the rang of 300-340 nm. Pretreatment sample has been done using SPE with the cartridge of C18 similar to the analyte column. The results found that a four predominant peaks for α and β-acids, namely cohumulone (6.6 min), the second peak represents a mixture of humulone and adhumulone (8.9 min), the third peak is colupulone (15.9 min) and the fourth is a mixture of lupulone and adlupulone (16.7 min). The quantity of sample has been determined according to multipoint calibration using ICE2 standard, the sample found are 0,209 g/L cohumulone, 1.087 g/L of humulone and adhumulone, 0,349 g/L of Colupulone and 0.630 g/L of mixture of lupulone and adlupulone. In addition it is high precision measurement that is indicated by the value of RSD less than 1%.

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Suwardiyanto

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+6282335157662

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icl@unej.ac.id

Editorial Address
Jl. Kalimantan 37 Kampus Tegalboto 68121

Location
Kab. jember,

Jawa timur

INDONESIA

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Home Page

OAI Link

Editorial Team

Contact

Reviewer

Google Scholar

Contact Name Suwardiyanto

Contact Email icl@unej.ac.id

Phone +6282335157662

Journal Mail Official icl@unej.ac.id

Editorial Address Jl. Kalimantan 37 Kampus Tegalboto 68121

Location Kab. jember, Jawa timur INDONESIA

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

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Contact Name
Suwardiyanto

Contact Email
icl@unej.ac.id

Phone
+6282335157662

Journal Mail Official
icl@unej.ac.id

Editorial Address
Jl. Kalimantan 37 Kampus Tegalboto 68121

Location
Kab. jember,

Jawa timur

INDONESIA