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All Journal VALENSI CAKRA KIMIA (Indonesian E-Journal of Applied Chemistry) Jurnal Kimia (Journal of Chemistry) Ecotrophic, Journal of Environmental Science JURNAL KIMIA SAINS DAN APLIKASI The Journal of Pure and Applied Chemistry Research Jurnal Riset Kimia Jurnal Kimia Riset ALCHEMY Jurnal Penelitian Kimia Indonesian Journal of Chemistry Chemistry Indonesian Journal of Chemical Research Jurnal Ilmu Pendidikan Indonesia Aceh International Journal of Science and Technology Seminar Ilmiah Nasional Teknologi, Sains, dan Sosial Humaniora (SINTESA)
Irdhawati Irdhawati
Department Of Chemistry, Faculty Of Mathematic And Natural Sciences, Udayana University, Bali 80361 Indonesia
Agriculture, Biological Sciences & Forestry Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Chemistry Computer Science & IT Control & Systems Engineering Decision Sciences, Operations Research & Management Earth & Planetary Sciences Education Electrical & Electronics Engineering Energy Engineering Environmental Science Health Professions Materials Science & Nanotechnology Mathematics Medicine & Pharmacology Physics Social Sciences

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Preparation and Validation of Fe2O3 Modified Carbon Paste Electrode for Measurement of Dopamine by Voltammetry Method Irdhawati Irdhawati; Manuntun Manurung; Ni Ketut Yuni Sri Lestari
Jurnal Kimia Sains dan Aplikasi Vol 22, No 6 (2019): Volume 22 Issue 6 Year 2019
Publisher : Chemistry Department, Faculty of Sciences and Mathematics, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (284.434 KB) | DOI: 10.14710/jksa.22.6.227-234

Abstract

Preparation and validation of the Fe2O3 modified carbon paste electrode have been carried out for the analysis of dopamine by the voltammetry method. Validation parameters of carbon paste electrodes (CPA) tested include linear concentration range, Limit of Detection (LoD), Limit of Quantification (LoQ), accuracy, and selectivity in the presence of ascorbic acid and uric acid. The results obtained in the optimization of the composition and condition of the Fe2O3 modifier in graphite are 0.8% mass at pH 6 solution with the Brinton Robinson buffer solution. The peak potential shifted 32 mV in the negative direction from the initial peak potential of 319 mV at the carbon paste electrode without modification to the peak potential of 287 mV at the 0.8% Fe2O3 modified carbon paste electrode. The linear concentration range at concentrations of 8 µM–100 µM obtained a linear equation y= 1.1204 + 0.1289x with R2=0.99943. LoD value obtained is 0.23 µM, and the LoQ is 0.77 µM. In the selectivity test obtained in the dopamine analysis using 0.8% Fe2O3 modified carbon paste electrode, the anodic peaks of dopamine (75 mV), ascorbic acid (190 mV), and uric acid (200 mV) can be separated. This method has acceptable repeatability because it produces a Horwitz Ratio value of 0.0417, which is smaller than two. Preparation and validation of 0.8% Fe2O3 modified carbon paste electrode can be declared as eligible for the measurement of dopamine.
PATTERN OF POTASSIUM RELEASE FROM SLOW RELEASE FERTILIZER POTASSIUM CLORIDE-BENTONITE FERTILIZER Carver J M; Suarya P; Irdhawati Irdhawati
Jurnal Ilmu Pendidikan Indonesia Vol 11, No 2 (2023): JURNAL ILMU PENDIDIKAN INDONSIA
Publisher : Program Magister Pendidikan IPA, Program Pascasarjana Universitas Cenderawasih

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31957/jipi.v11i2.3074

Abstract

Potassium has an important role in the process of plant growth, but its presence and availability in the soil are limited, because potassium is easily lost and flows out by water. Increasing the efficiency of potassium fertilization can be pursued through the formulation of fertilizer in the form of slow-release fertilizer (SRF) using bentonite.  This study aimed to determine the release of potassium in potassium chloride fertilizer into the soil after bonding with acid-activated bentonite coated with potassium chloride. The composition of the KCl fertilizer made varies with bentonite with a mass ratio (g) of 1:1; 2:1; 3:1; 4:1; and 5:1, with a percolation time of 28 days. The concentration of released potassium was determined using an atomic absorption spectrophotometer. Material characterization was carried out by FTIR. The results showed that the ratio 1:3 had the highest potassium content of 45.12% with an incubation time of 28 days. The concentration of released potassium on day 7; 14; 21; and 28 respectively (12.55±1.25)%, (28.39±1.49)%, (5.,91±0.98)%, and (70.49±1.36)% . The results of the characterization of the determination of the fungal group on SRF3 were not significantly different from that of activated bentonite. Even though there were differences in the intensity of certain peaks and changed the functional groups.
PEMANFAATAN EKOENZIM DARI KULIT BUAH-SAYUR UNTUK PENINGKATAN KUALITAS AIR DANAU BATUR DI KECAMATAN KINTAMANI BANGLI, BALI Suyasa, I Wayan Budiarsa; Susanah Rita, Wiwik; Irdhawati, Irdhawati; Gede Widihati, Ida Ayu; Wirajana, Nengah; Sibarani, James
ECOTROPHIC : Jurnal Ilmu Lingkungan (Journal of Environmental Science) Vol 18 No 1 (2024)
Publisher : Master Program of Environmental Science, Postgraduate Program of Udayana University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.24843/EJES.2024.v18.i01.p08

Abstract

Eco enzyme production through the fermentation process of household waste, such as leftover fruit and vegetables can also be a solution to minimize waste from its source. This research aims to determine the effect of a mixture of organic materials, fruit and vegetable waste eco enzyme on pH, and the effect of eco enzyme dosage on improving the water quality of Lake Batur, Kintamani Bali. Making eco enzymes using vegetable and fruit waste. water, molasses in a ratio of 3: 10: 1. The liquid is fermented for 3 months while observing the fermentation process. Eco enzyme is harvested and filtered, ready for testing to improve the water quality of Lake Batur. The results of observations of making eco enzyme can be explained that in the first 4 weeks, there was a change in colour with shades of brown to reddish, after the fourth week the colour was relatively stable (no colour change. Changes in pH during the process of making eco enzymes were related to variations in the composition of organic material (vegetable residues. There was a decrease in pH). with an average of up to 1 digit, the highest reduction occurred in ingredients containing papaya, mango and mustard greens. Eco enzymes can improve water quality as indicated by several water quality parameters, but are not enough to achieve conformity with the established quality standards. Keyword: Eco Enzyme; Water Quality; Batur Lake
Serbuk Gergaji Kayu Jati Teraktivasi EDTA Sebagai Penjerap Ion Tembaga (II) dan Krom (III) Irdhawati, Irdhawati; Triyunita Sinthadevi, Ni Nyoman; Sahara, Emmy
Indonesian Journal of Chemical Research Vol 7 No 2 (2020): Edisi Bulan Januari (Edition for January)
Publisher : Jurusan Kimia, Fakultas Sains dan Teknologi, Universitas Pattimura

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30598/ijcr.2020.7-ird

Abstract

Teak sawdust is a waste of the furniture industry. The main compound content is cellulose, which contains hydroxyl groups so that can be used as adsorbent. This work aims to determine adsorption capacity and isotherm adsorption pattern of teak sawdust activated by EDTA for copper (II) dan chromium (III) ions. Some parameters were optimized including the ratio of adsorbent and EDTA, and contact time. The results showed the optimum ratio of teak sawdust and EDTA was 2:3, and the optimum contact time was 105 minutes. Both of isoterm adsorption patterns of teak sawdust to Cu (II) and Cr (III) ions follow the Freundlich equation, with determination coefficient close to one. Optimum adsorption capacity was obtained 46.5 and 39.7 mg/g for Cu (II) and Cr (III), respectively.
Co-Authors Alling Andini Anak Agung Bawa Putra Anisha Maulinasari Arisma Damayanti Ayu Jyostosya Yotirani Arya Wijana Carver J M Ekki Inur Ingtyas Mawarni Emmy Sahara Feby Silvia Feby Silvia Sitio Gede Widihati, Ida Ayu Henu Sumekar Hery Suyanto Hery Suyanto I Gusti Ayu Putu Yunita Riyastini I W BUDIARSA SUYASA I Wayan Hermawan I. A. R. Astiti Asih Ida Ayu Gede Widihati Iryanti Eka Suprihatin James Sibarani Liana Sari Made Arsa Manuntun Manurung Manuntun Manurung Nadya Sarilla Agatha Ni G. A. M. Dwi Adhi Suastuti Ni Kadak Nevi Titasia Ni Ketut Esati Ni Ketut Shinta Mas Methaninditya Ni Ketut Yuni Sri Lestari Ni Made Puspawati Ni Putu Antari Dewi Ni Putu Gita Widi Saraswati Nur Alisyah Gani Nyoman Sudarma Putu Yani Andani Rosanti Suryani Tince Mbatu Suarya P Titasia, Ni Kadak Nevi Triyunita Sinthadevi, Ni Nyoman Vivi Eka Indrayani Wirajana, Nengah WIWIK SUSANAH RITA Yudha Taufantri