Claim Missing Document
Check
Articles

Found 24 Documents
Search

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.
ZEOLITE-MODIFIED CARBON PASTE ELECTRODE FOR DETERMINATION OF COPPER USING ANODIC STRIPPING VOLTAMMETRY METHOD Irdhawati Irdhawati; Hery Suyanto; Putu Yani Andani
ALCHEMY Jurnal Penelitian Kimia Vol 13, No 1 (2017): March
Publisher : UNIVERSITAS SEBELAS MARET (UNS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/alchemy.13.1.1808.1-16

Abstract

In this research, the unmodified and modified carbon paste electrode with zeolite has been prepared, for determination of Cu(II) using anodic stripping voltammetry method. The parameters observed involved deposition time, scan rates, zeolite composition in carbon paste, and validation of working electrode. The optimum performance of carbon paste electrode modified with zeolite was applied for determination of Cu(II) in wastewater of the gong fabrication. The results of this research showed the optimum of deposition time and scan rates obtained at 410 s and 7.5 mV/s for unmodified carbon paste electrode, respectively. The optimum composition of zeolite-modifier is 20% from total graphite, with deposition time 380 s and scan rates 10 mV/s. The detection limit of the measurement of Cu(II) standard solution using unmodified carbon paste electrode is 46.13 ppb, is lower than unmodified carbon paste electrode, 99.93 ppb. Zeolite-modified carbon paste electrode has good precision and accuration. The concentration of Cu(II) in waste water of gong fabrication , using carbon paste electrode modified with zeolite is 93.54 ± 0.87 ppb.
Teknik Differential Pulse Voltammetry Menggunakan Elektroda Pasta Karbon Termodifikasi Fe2O3 untuk Penentuan Kadar Fe(III) dalam Air Laut di Pelabuhan Benoa Bali Irdhawati Irdhawati; Ni Putu Antari Dewi; Ida Ayu Gede Widihati
ALCHEMY Jurnal Penelitian Kimia Vol 17, No 1 (2021): March
Publisher : UNIVERSITAS SEBELAS MARET (UNS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/alchemy.17.1.41568.54-62

Abstract

Pelabuhan Benoa merupakan salah satu pelabuhan di Provinsi Bali tempat berlabuhnya kapal/perahu nelayan, kapal penumpang, dan kapal untuk pariwisata. Aktivitas masyarakat di sekitar pelabuhan dapat menjadi sumber pencemar logam berat. Penelitian ini bertujuan untuk mengetahui hasil optimasi dan validasi elektroda pasta karbon tanpa modifikasi (EPK) dan EPK termodifikasi Fe2O3 (EPK Fe2O3) dengan teknik differential pulse voltammetry (DPV) untuk pengukuran Fe(III) dalam sampel air laut di Pelabuhan Benoa. Parameter yang dioptimasi yaitu laju pindai dan komposisi Fe2O3 dalam pasta karbon. Selanjutnya dilakukan validasi pengukuran, meliputi rentang konsentrasi linier, limit deteksi, limit kuantisasi, keberulangan, dan persen perolehan kembali. Hasil yang diperoleh yaitu laju pindai optimum 15 mV/s menggunakan EPK, menjadi lebih cepat yaitu 20 mV/s menggunakan EPK Fe2O3. Komposisi modifier terbaik dalam pasta karbon sebesar 0,5%. Rentang konsentrasi linier pengukuran menggunakan EPK yaitu 5 ~ 100 mg/L menjadi 5 ~ 2000 mg/L pada EPK Fe2O3. Limit deteksi dan limit kuantisasi menggunakan EPK Fe2O3 masing-masing 0,5490 mg/L dan 0,5497 mg/L, lebih rendah daripada menggunakan EPK yaitu 1,0667 mg/L dan 1,0688 mg/L. Keberulangan pengukuran menghasilkan rasio Horwitz yang lebih kecil dari dua. Nilai persen perolehan kembali pengukuran larutan standar dengan matriks larutan sampel yang diambil pada tiga lokasi yang berbeda, yaitu pada Dermaga Barat 97,51±9,92% ; Dermaga Selatan 101,18±10,60%; dan Dermaga Timur 95,50±1,23%. Hasil pengukuran Fe(III) dalam sampel diperoleh 129,98±13,65 mg/L; 114,85±13,75 mg/L; dan 127,77±4,01 mg/L, masing-masing pada Dermaga Barat, Selatan, dan Timur.Differential Pulse Voltammetry Technique Using Fe2O3 Modified Carbon Paste Electrode for Determination of Fe(III) Levels in Seawater at Benoa Harbor Bali. Benoa Port is one of the ports in the Province of Bali where fishing boats, passenger ships, and ships for tourism are anchored. Activities around the port can be a source of heavy metal pollutants. This study aims to optimize and validates carbon paste electrodes without modification (EPK) and modified by Fe2O3 (EPK Fe2O3) using differential pulse voltammetry (DPV) techniques for Fe (III) measurements in seawater at Benoa Harbor. The optimized parameters were scan rate and the Fe2O3 composition in carbon paste. Meanwhile, the validation was performed, including the range of linear concentration, detection limit, quantitation limit, repeatability, and percent of the recovery. The research found that the optimum scan rate was 15 mV/s using EPK, become faster to 20 mV/s using EPK Fe2O3. The optimum modifier composition in carbon paste was 0.5%. The linear concentration range of measurement using EPK was 5 ~ 100 mg/L to 5 ~ 2000 mg/L at EPK Fe2O3. The detection limit and the quantitation limit using EPK Fe2O3 were 0.5490 mg/L and 0.5497 mg/L, respectively. Those are lower than the detection limit quantitation by EPK i.e., 1.0667 mg/L and 1.0688 mg/L, respectively. Repeated measurements produce a Horwitz ratio which is less than two. The percent of recovery value of the measurement of the standard solution with the sample solution matrix taken from the three different locations are 97.51±9.92% for the West Pier region; 101.18±10.60% for the South Pier region; and 95.50±1.23% for the East Pier region. The Fe(III) measurements to the different samples from the West Pier, South Pier, and East Pier regions were 129.98±13.65 mg/L; 114.85±13.75 mg/L; and 127.77±4.01 mg/L, respectively.
Modification of Carbon Paste Electrode with Crown Ether (Dibenzo-18-Crown-6) for Ascorbic Acid Analysis Using Differential Pulse Voltammetry Method Irdhawati Irdhawati; Manuntun Manurung; Anisha Maulinasari
ALCHEMY Jurnal Penelitian Kimia Vol 11, No 2 (2015): September
Publisher : UNIVERSITAS SEBELAS MARET (UNS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20961/alchemy.11.2.728.175-191

Abstract

In this research, the modified carbon paste electrode with crown ether (dibenzo-18-crown-6) has been prepared, for determination of ascorbic acid. Some of parameters observed were optimization of crown ether composition in carbon paste, pH of solution, linear concentration range, limit of detection, reproducibility, and recovery. The optimum performance of the prepared electrode was applied for determination of commercialsampleswhich contain of ascorbic acid. The result of this research showsthat the optimum composition of crown ether in carbon paste is 0.6 % at pH 4. Linear range of concentration obtained is from 2 - 200 μM. The detection limit and percentage of recovery are 1.243 μM and 101.31 %, respectively. The modified electrode has HorRat value less than 2, it indicates a good reproducibility. Analysis of 4 commercial samples which contain of ascorbic acid were in agreement with the content listed in the label with the suitability of 94 - 100 %.