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All Journal Jurnal Ilmu Dasar BERKALA SAINSTEK EduChemia: Jurnal Kimia dan Pendidikan UNEJ e-Proceeding Jurnal Kimia Riset Jurnal Biodjati Jurnal Ilmiah Universitas Batanghari Jambi Indonesian Journal of Chemistry JKPK (Jurnal Kimia dan Pendidikan Kimia) Indonesian Chimica Letters
Siswoyo Siswoyo
Department of Chemistry, Faculty of Mathematics and Science, University of Jember, Jember 68121
Agriculture, Biological Sciences & Forestry Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Chemistry Civil Engineering, Building, Construction & Architecture Control & Systems Engineering Earth & Planetary Sciences Economics, Econometrics & Finance Education Law, Crime, Criminology & Criminal Justice Materials Science & Nanotechnology Mathematics Physics

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Optimisation of Extractant and Extraction Time on Portable Extractor Potentiometric Method for Determining Phosphate in Soil Anggia Rose Sukaton; Siswoyo Siswoyo; Bambang Piluharto
UNEJ e-Proceeding 2016: Proceeding The 1st International Basic Science Conference
Publisher : UPT Penerbitan Universitas Jember

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

Phosphorus is one of the nutrients which is needed by plants in large amounts. Fertilisation is a popular solution for supplying a sufficient amount of phosphorus in the soil. However, phosphorus can pollute water bodies and lead to eutrophication if fertilisation is carried out without considering prior information about the soil condition. Thus, analysis of phosphorus needs to be done before fertilisation. This paper is reporting a result in development an alternative strategy for analysing the phopsphorus in soil agriculture using potentiometric method. The aims of this research were to find the optimum condition of extractant and extraction time for determining phosphate, one form of phosphorus, in soil and evaluate a portable extractor potentiometric (PEP) method for determining phosphate in soil. Measurement of phosphate was undertaken by using cobalt working electrode, silver-silver chloride reference electrode and 0,025 M potassium hydrogen phtalate at pH 4 as ionic strength adjuster. Evaluation of PEP method was carried out by comparing this method with both the conventional potentiometric (CP) and the standard spectrometric (SS) methods. It was found that Kelowna was the optimum extractant for measuring phosphate potentiometrically in soil by CP method. Extraction time of 10 minutes was the optimum time for extracting phosphate in soil using Kelowna extractand solution. The result also shown that correlation between PEP and CP method was 0.883 whereas correlation between PEP and SS method was 0.924. Linear response characterisation of both PEP and CP method has obtained slope of (-28.47) and (-23.67) mV per decade respectively, in other hand the PEP and CP has resulted the detection limit 0.72 ppm and 0.83 ppm respectively. Repeatability for both PEP and CP method were less than 5%.
OPTIMASI PARAMETER TEKNIK SQUARE WAVE VOLTAMMETRY DENGAN ELEKTRODA GRAFIT FAN PENERAPANNYA PADA ANALISIS KLORIN BEBAS DALAM AIR CUCIAN BERAS BERPEMUTIH Fenly Arismaya; Siswoyo Siswoyo; Asnawati Asnawati
Jurnal Kimia Riset Vol. 3 No. 2 (2018): Desember
Publisher : Universitas Airlangga

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (586.588 KB) | DOI: 10.20473/jkr.v3i2.8704

Abstract

AbstrakKlorin (OCl-) merupakan bahan kimia berbahaya bagi kesehatan manusia, yang kadang digunakan sebagai bahanpemutih beras.  Oleh  sebab  itu  dilakukan  upaya  analisis  Klorin  menggunakan  teknik  Square  Wave  Voltammetry.  Penelitian  ini melakukan optimasi pengaturan parameter (konsentrasi larutan elektrolit, pH, dan sampling time) dan karakterisasi metode kerja dari teknik Square Wave Voltammetry, sehingga teknik ini dapat diaplikasikan untuk analisis klorin bebas (OCl-) dalam air cucian beras berpemutih. Variasi konsentrasi larutan elektrolit yang diterapkan dalam penelitian ini adalah 0,05; 0,10; 0,15; 0,20; 0,25 M. Variasi pH yang diterapkan pada pH 7, 8, 9, 10, 11, dan 12. Variasi sampling time yang diterapkan adalah 5, 10, 15, dan 20 milisekon. Berdasarkan hasil penelitian yang diperoleh, konsentrasi larutan elektrolit optimum pada konsentrasi 0,15 M, pH optimum pada kondisi pH 9, dan sampling time optimum adalah 10 milisekon. Hasil karakterisasi kinerja metode pada teknik Square Wave Voltammetry yang telah dioptimasi ini menghasilkan linieritas 0,9885, limit deteksi sebesar 9,563 ppm, dan nilai koefisien variasi sebesar 4,09%. Hasil pengukuran konsentrasi klorin bebas (OCl-) dengan teknik Square Wave Voltammetry yang telah dioptimasi adalah senilai 30,125 ppm. Pengaturan tiga parameter tersebut berpengaruh terhadap bentuk dan ketinggian puncak voltamogram yang dihasilkan. Kata Kunci: Square Wave Voltammetry, Optimasi Parameter, Klorin bebas, Beras Berpemutih.
Voltammetric Synthesis of Conducting Polymer Polypyrrole and Its Response Characteristic to Alcohol Susi Nurqomariyah; Asnawati Asnawati; Neran Neran; Siswoyo Siswoyo
Jurnal ILMU DASAR Vol 16 No 2 (2015)
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam Universitas Jember

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (243.328 KB) | DOI: 10.19184/jid.v16i2.1485

Abstract

Conducting polymer is a used material for many purposes, including active compound of chemical sensor. Polypyrrole, one type of conducting polymers, is frequently used because of its advantages, namely owing high conductivity, strong mechanical properties and relatively stable compound.  This research was aimed to develop an alcohol sensor based on polypyrrole. Electropolymerisation of the polypyrrole was carried out using cyclic voltammetric technique. This research investigated some parameters electropolymerisation, namely variation of dopant electrolyte concentration, potential scan-rate, surface morphology of the polymer resulted, characteristic of the sensor performance when exposed to some alcohol compounds. According to the result of investigation, it was found that variation of potential scan-rate and dopant concentration has significant effect to the electropolymerisation process as well as to the resulted polymer, as indicated by the voltammogram profiles, the surface morphology of the resulted polymer and the response of resistance change of the polymer when exposed to the alcohol compounds.Keywords: polypyrrole, conducting polymer, alcohol sensor, cyclic voltammetry, electropolymerisation.
FLOW INJECTION POTENTIOMETRIC ANALYSIS OF ASPARTIC ACID, GLUTAMIC ACID AND ASCORBIC ACID USING PLATINUM ELECTRODES Yeni Maulidah Muflihah; Siswoyo Siswoyo; Tanti Haryati; Kiki Puji Setianingrum
Jurnal ILMU DASAR Vol 13 No 1 (2012)
Publisher : Fakultas Matematika dan Ilmu Pengetahuan Alam Universitas Jember

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (314.474 KB) | DOI: 10.19184/jid.v13i1.886

Abstract

The presence of  weak acids in solution can be detected using a potentiometric detector. Platinum was used as a working electrode and Ag/AgCl as a reference electrode. Ascorbic, glutamic and aspartic acid were detected by a platinum electrode in a flow potentiometric system. The influence of pH, flow rate and concentration of phosphate buffers asa a carrier were studied and showed an optimum pH for the detection of ascorbic and glutamic acid at pH 6,5 and pH 7,0 for aspartic acid. Phosphate buffer concentration optimum at 1x10-4M and flow rate of 1,00 mL/min. Linear range for ascorbic and glutamic acid at 2,5 x10-4M to 5x10-2M, with a regression coefficient of  0,974 and 0,958, while for aspartic acid 5x10-4M to 5x10-2M with a regression coefficient 0,911. Detection limit for ascorbic and glutamic acids were 5x10-4M and 1x10-3M for aspartic acid. Sensor reproducibility obtained from variation coefficient  (Kv). Variation coeffiecient (Kv) of ascorbic acids 1,32-1,69%, glutamic acids 0,69- 1,57% and aspartic acid 0,54- 1,29%.
ELECTROPOLYMERISATION AND CHARACTERISATION OF DOPED-POLYPYRROLE AS HUMIDITY SENSOR Siswoyo Siswoyo; Trio F. Nugroho; Zulfikar Zulfikar; Agus Subekti
Indonesian Journal of Chemistry Vol 6, No 2 (2006)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (354.256 KB) | DOI: 10.22146/ijc.21759

Abstract

A new type of sensing materials for humidity measurement has been developed based on conducting polymer polypyrrole synthesised from pyrrole by adding some dopant compounds, bromide and chloride, it is prepared by potentiodynamic-electropolymerisation technique. Variation of dopant types and concentration has been carried out in order to investigate the effect of this variation to the change of polymeric conductivity when interacting with water vapour. Polypyrrole-Cl (Ppy-Cl) and polypyrrole-Br (Ppy-Br) exhibit a good principal characteristic as sensor candidate namely responding proportionally to humidly variation ranging 30% - 90% relative humidity. Characterisation test for the sensor candidates has been carried out for evaluating their linearity respond toward humidity, their stability in certain period and their reproducibility in some tests. The results show that Ppy-Cl and Ppy-Br showing good linearity respond with R value in a range of 0.95 - 0.99. Their reproducibility and sensitivity were relatively good, however their respond stability were only last in few days. The stability probably is related to the stability of resulted polymeric structure that very affected by synthesis process and dopant used. It is necessary to extend the use of other dopant materials and changing the synthesis process in order to improve sensor stability. In other hand it is also necessary to characterise other performance characteristic of the sensor namely response time, and interference effect of some volatile chemicals and other gases.
An Extracellular Pectinase from ISH16 Bacteria Isolated Induced by Coffee Pulp Waste Substrate Kahar Muzakhar; Farah Salma Elida; Ramdhan Putrasetya; Siswoyo Siswoyo; Rudju Winarsa; Hidayat Teguh Wiyono
Jurnal Biodjati Vol 7, No 2 (2022): November
Publisher : UIN Sunan Gunung Djati Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15575/biodjati.v7i2.20279

Abstract

An α-1,4-glycosidic bonds galactoses pectin, mainly composed of a D-galacturonic acid chain, are important biomaterial widely used in industries. Utilizing this material, a bioprocess, including the biocatalysis pectinase, is often needed. Pectinase production was optimized in 7 days SSF at 37°C, and the pectinase activities were daily measured by the method of Somogy-Nelson. The optimum pectinase production was 0.166 U/ml on the fourth day SSF. Purification using open column ion exchange chromatography DEAE cellulose DE-52 resulted in 1030.9 folds of pectinase purity with a yield of 25.9%. The enzyme was at optimal activity at pH six and attended stable in the pH range of 5.5-8, while optimal activity at a temperature of 50°C and was stable in the range of 30-45°C. The pectinase activity increased by 120% with the addition of 10 mM Mg2+, and 95% retained when 10 mM Ca2+ was added. The presence of 10 mM Na+, K+, and Fe2+ resulted in a slight effect of activity at 85%, 83%, and 78%. However, it was strongly inhibited by 10 mM Al3+ and retained 25%. Based on the results above, the microbial utilization of coffee pulp waste by ISH16 bacteria pectinolytic is one opportunity to produce valuable pectinase with low-cost production, so comprehensive examination in large-scale production is needed too. In this paper, all research detail steps were described.
The Effect of Testing Chamber on the Response Patterns of an array of Gas Sensor in Sensing Robusta Coffee Aroma from Bangsalsari and Sidomulyo, Jember Asnawati Asnawati; Siswoyo Siswoyo; Febiola Silvia Ningsih; Qurotul Ainiyah; Zulfikar Zulfikar; Tri Mulyono; Yeni Maulidah Muflihah
JKPK (Jurnal Kimia dan Pendidikan Kimia) Vol 8, No 1 (2023): JKPK (Jurnal Kimia dan Pendidikan Kimia)
Publisher : Program Studi Pendidikan Kimia FKIP Universitas Sebelas Maret

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/jkpk.v8i1.68520

Abstract

The gas sensor performance can be improved by optimizing the testing chamber design, including volume, shape, gas inlet/outlet positions, and sensor array. We studied the effect of chamber design on the gas sensor's response patterns characteristics in differentiating Robusta coffee aroma from Sidomulyo, and Bangsalsari, Jember. Hemisphere and cylindrical chambers, with three variations for each model, and a ring chamber, were used as model chambers. Eight types of gas sensors (MQ-135, MQ-136, MQ-2, MQ-3, MQ-6, MQ-7, MQ-8, and MQ-9) were used in the sensor array system to examine the gas sensor instrument performance. The resulting responses were analyzed using the reproducibility, response time, and principal component analysis (PCA) test. The result shows that the reproducibility value for all hemisphere chamber models, cylindrical chamber model-1, and ring chamber indicated an excellent sensor performance (%RSD<20%). Meanwhile, the cylindrical chambers model-2 and 3 resulted in %RSD>20%, indicating the low performance of the gas sensor. Among all variations, hemisphere chamber model-1, a hemisphere chamber with the inlet position lower than the outlet gas position, has the best performance due to the shortest response time, high-intensity signal, and performing ability to distinguish the response patterns characteristics of Robusta coffee aroma from Sidomulyo and Bangsalsari, Jember, Indonesia. In this study, we found that changing the testing chamber design, volume, and inlet/outlet position resulting different gas sensor responses to the coffee aroma. The proposed instrument can distinguish the coffee aroma from a different origin.
Optimasi dan Karakterisasi Kinerja Sistem Pengukuran Potensiometrik Fosfat dengan Elektroda Kobalt Secara Flow Injection Analysis Putri F. Rianasari; Zulfikar Zulfikar; Siswoyo Siswoyo
Jurnal Ilmiah Universitas Batanghari Jambi Vol 23, No 2 (2023): Juli
Publisher : Universitas Batanghari Jambi

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33087/jiubj.v23i2.3714

Abstract

Phosphorus is known as an essential nutrient required by plant in large numbers and absorbed in the form of phosphate ions, either as a primary orthophosphate ion H2PO4- or secondary orthophosphate ion HPO42-. Concentration of the phosphorus in the soil is usually determined by the spectrophotometric method, while the potentiometric method has not been widely used because of the availability of the phosphate-selective electrodes are not yet available in the market. This research has been conducted in the development and assessment of performance of the potentiometric method that utilizes cobalt metal in the quantitative determination of the phosphate ions in the flow system. Firstly it was performed optimization of pH and concentration of the used buffer solution and the flow rate of the solution to obtain the optimum response of the cobalt electrode in the presence of phosphate ions. It was then followed by an evaluation of the working performance of the flow injection potentiometry method and an interference test of some solutions that are commonly used as a solvent extractors of soil samples. The result showed that the optimum system was achieved when the buffer solution was set to pH 4 at concentration of 1 x 10-3 M and at the flow rate of 2 mL/minute. According to the characterisation results of the method in the process of phosphate determination, the method has a linearity of 0.99, detection limit of 4.86 x 10-5 M, sensitivity of 22.569 mV / decade and precision of ≤ 5%.
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

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (674.69 KB) | DOI: 10.19184/icl.v1i1.4

Abstract

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.
PEMANFAATAN MIKROKONTROLER DALAM PENGEMBANGAN INSTRUMEN UKUR KONDUKTIFITAS UNTUK ANALISIS KUALITAS AIR Surya Primaswara, Alfisa; Neran, Neran; Siswoyo, Siswoyo
BERKALA SAINSTEK Vol 4 No 1 (2016)
Publisher : Universitas Jember

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Abstract

Salah satu upaya pemantauan kualitas air adalah dengan melakukan analisis terhadap konduktifitas atau daya hantar listrik dari sampel air. Saat ini alat ukur yang banyak digunakan masih berasal dari pabrikan dengan harga yang relatif mahal sehingga ketersediannya dalam laboratorium universitas sangat terbatas dan sangat tergantung dari pabrikan dimaksud. Penelitian ini bertujuan untuk mengembangkan instrumen pengukur konduktifitas air dengan memanfaatkan mikrokontroller dan mengintegrasikannya dengan sensor daya hantar listrik. guna menentukan analisa kualitas air. Penelitian dilaksanakan dalam empat tahap yaitu pembuatan perangkat keras, pembuatan perangkat lunak, pengkalibrasian instrumen dilanjutkan dengan uji pengukuran terhadap sampel air dibandingkan dengan instrumen standar pembanding, dan analisis data yang diperoleh. Standar konduktifitas menggunakan larutan KCl pada konsentrasi 0,001 M sampai 0,01 M. Hasil Penelitian menunjukkan bahwa instrumen berbasis mikrokontroler ini mempunyai kemampuan range pembacaan daya hantar listrik air antara 0,209 mS sampai dengan 1,468 mS sesuai dengan range standarisasi KCl, dengan nilai prosentasi akurasi pengukuran sebesar 92,8%, dan nilai presisi Kv dibawah 5%. Tidak terdapat perbedaan hasil pengukuran yang signifikan jika dibandingkan dengan hasil pengukuran instrumen standar.
Co-Authors Agus Subekti Anggia Rose Sukaton Anida, Choirun Nisa Ardyanti, Zona Salsabila Asnawati Asnawati Asnawati Asnawati Asnawati Asnawati, Asnawati Bambang Piluharto Farah Salma Elida Febiola Silvia Ningsih Fenly Arismaya Hidayat Teguh Wiyono Indradewa, Rhian Kahar Muzakhar Kiki Puji Setianingrum Maulidah Muflihah, Yeni Mintadi, Mukh. Muflihah, Yeni Maulidah Muhammad Reza Mulyono, Tri Neran Neran Neran Neran Putri F. Rianasari Qurotul Ainiyah Ramdhan Putrasetya Surya Primaswara, Alfisa Susi Nurqomariyah Tanti Haryati Tri Mulyono Trio F. Nugroho Wijayanti, Chatarina Winarsa, Rudju Yeni Maulidah Muflihah Yeni Maulidah Muflihah Zein, Inayatul Aulia Rizka Zulfikar Zulfikar Zulfikar Zulfikar Zulfikar, Zulfikar