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Voltametri Pelucutan Anodik Menggunakan Elektroda Pasta Karbon Termodifikasi Bentonit untuk Penentuan Kadar Ion Cd(II) dalam Sayur Sawi Putih Irdhawati, Irdhawati; Titasia, Ni Kadak Nevi; Sahara, Emmy
Jurnal Riset Kimia Vol 12, No 2 (2021): September
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v12i2.417

In this study, the measurement of Cd(II) ion by anodic stripping voltammetry technique was conducted using bentonite modified carbon paste as working electrode (CPE-B). The performance of CPE-B was compared with carbon paste electrode without bentonite (CPE) and applied for determination of Cd(II) concentration in chicory. Optimized parameters were composition of bentonite in carbon paste electrode, deposition time, deposition potential, and scan rate. Validation of measurements was observed including determination of linear concentration range, detection and quantization limits, repeatability of measurement, and percentage of recovery. The optimum composition of bentonite in CPE-B was found at 50%. Furthermore, in the optimization of measurements condition was found the optimum deposition times were 90 and 60 s, deposition potentials were -0.63 and -0.53 V, and scan rates were 15 and 20 mV/s, for CPE and CPE-B. The linear range concentration for CPE observed at 25-2000 Âµg/L and CPE-B was 5-50 Âµg/L. Limit of detection and quantization using CPE-B were 0.337 Âµg/L and 0.349 Âµg/L, lower than CPE i.e., 0.470 Âµg/L and 0.471 Âµg/L, respectively. Repeatability measurement of Cd(II) had Horwitz Ratio value less than two, and percentage of recovery was 96.73 8.33%. The level of Cd(II) ion in chicory was found at 6.98 0.40 mg/kg.

Sintesis dan Karakterisasi Grafena dengan Metode Reduksi Grafit Oksida Menggunakan Pereduksi Zn Yudha Taufantri; Irdhawati Irdhawati; Ida Ayu Raka Astiti Asih
Jurnal Kimia Valensi Jurnal Kimia VALENSI Volume 2, No. 1, Mei 2016
Publisher : Syarif Hidayatullah State Islamic University

Graphene is a thin material, has a hexagonal two-dimentional lattice and is considered as an interesting material for adsorption process. Nowadays, graphene has been known as a potential material for diverse application, such as adsorbent. In this study graphene was synthesized from graphite. Furthermore, graphene was applied for adsorption of dichloro diphenyl trichloroethane (DDT). Graphene was synthesized by Hummer’s method using hydrothermal and reduced by Zn. The samples were characterized by Scanning Electron Microscope (SEM) and X-Ray Diffraction (XRD) methods. The results of the XRD showed graphene structure in the 2θ, appeared at 23.9369 with interlayer spacing was about 3.71763 Å, compared with graphite oxide structure in the 2θ appeared at 11.2055 with interlayer spacing was about 7.89649 Å. The results of SEM analysis showed graphene has one layer with planar hexagonal structure and seems transparent whose single layer and multi layers. The graphene adsorption was analyzed by using the UV-Visible spectrophotometer. The results indicated the surface area of graphene was shown as 46.8563 m2/g. The amount of DDT adsorbed by graphene during 15 minutes was 7.5859 mg/g. This adsorption mechanism of DDT and graphene might be due to π-π and hydrogen interactions. Keywords: Adsorption, dichloro diphenyl trichloroethane (DDT), graphena. DOI: http://dx.doi.org/10.15408/jkv.v2i1.2233

Analisis Logam Fe dengan Teknik Voltammetri Pelucutan Anodik Pulsa Diferensial dalam Tanaman Pakcoy dari Perkebunan Sayur Bedugul Bali Irdhawati Irdhawati; Rosanti Suryani Tince Mbatu; Emmy Sahara
Jurnal Kimia Valensi Jurnal Kimia VALENSI Volume 4, No. 2, November 2018
Publisher : Syarif Hidayatullah State Islamic University

Pakcoy is one of the most popular vegetable. The use of synthetic fertilizers and pesticides contain heavy metals can contaminate pakcoy vegetable. This research aims to determine the validity of measurements and concentration of Fe in pakcoy using differential pulse anodic stripping voltammetry technique.The working, reference, and counter electrodes were platinum disk, Ag/AgCl, and Pt wire, respectively. The optimum measurement results of the standard solutions of Fe(III) obtained the optimum deposition time was 70 seconds, the optimum scan rate was 10 mV/s, and the optimum deposition potential at -0.47 V. A linear concentration of standard solution of Fe(III) observed at the range of 50 ppb~500 ppb, with correlation coefficient 0.9954. Limit of detection was 50.18 ppb. The repetition of 10 times measurements had a Horwitz ratio of less than 2. Percent recovery was 100.26% ± 0.27%. The average of Fe(III) concentration in the samples from 5 (five) locations of the pakcoy sampling contains 3.82±0.29 ppm, less than SNI treshold line of 5.0 ppm.

Voltametri Pelucutan Anodik Menggunakan Elektroda Pasta Karbon Termodifikasi Bentonit untuk Penentuan Kadar Ion Cd(II) dalam Sayur Sawi Putih Irdhawati Irdhawati; Ni Kadak Nevi Titasia; Emmy Sahara
Jurnal Riset Kimia Vol. 12 No. 2 (2021): September
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v12i2.417

In this study, the measurement of Cd(II) ion by anodic stripping voltammetry technique was conducted using bentonite modified carbon paste as working electrode (CPE-B). The performance of CPE-B was compared with carbon paste electrode without bentonite (CPE) and applied for determination of Cd(II) concentration in chicory. Optimized parameters were composition of bentonite in carbon paste electrode, deposition time, deposition potential, and scan rate. Validation of measurements was observed including determination of linear concentration range, detection and quantization limits, repeatability of measurement, and percentage of recovery. The optimum composition of bentonite in CPE-B was found at 50%. Furthermore, in the optimization of measurements condition was found the optimum deposition times were 90 and 60 s, deposition potentials were -0.63 and -0.53 V, and scan rates were 15 and 20 mV/s, for CPE and CPE-B. The linear range concentration for CPE observed at 25-2000 Âµg/L and CPE-B was 5-50 Âµg/L. Limit of detection and quantization using CPE-B were 0.337 Âµg/L and 0.349 Âµg/L, lower than CPE i.e., 0.470 Âµg/L and 0.471 Âµg/L, respectively. Repeatability measurement of Cd(II) had Horwitz Ratio value less than two, and percentage of recovery was 96.73 8.33%. The level of Cd(II) ion in chicory was found at 6.98 0.40 mg/kg.

KANDUNGAN LOGAM Pb DAN Hg DALAM SEDIMEN DI MUARA SUNGAI MATIKABUPATEN BADUNG BALI Henu Sumekar; Iryanti E. Suprihatin; Irdhawati Irdhawati
CAKRA KIMIA (Indonesian E-Journal of Applied Chemistry) Vol 3 No 2 (2015)
Publisher : Magister Program of Applied Chemistry, Udayana University, Bali-INDONESIA

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ABSTRAK :Aktivitas manusia disepanjang aliran Sungai Mati dapat menghasilkan bahan pencemar yang kemungkinan mengandung logam berat. Logam berat yang masuk perairan akan mengalami akumulasi di sedimen. Penelitian ini bertujuan untuk mengetahui kandungan logam Pb dan Hg dalam sedimen di muara Sungai Mati, Kabupaten Badung, Bali.Penentuan konsentrasi Pb dan Hg menggunakan Spektrofotometer Serapan Atom dengan metode standar adisi. Kandungan Pb yang diperoleh dalam sedimen yaitu 99,2442 ± 0,0031 mg/kg dan kandungan Hg adalah 142,8514 ± 0,0648µg/kg. Kandungan Pb dan Hg di muara Sungai Mati tersebut melebihi ambang batas yang telah ditentukan.ABSTRACT:Human activities along the river banks such as Mati River can potentially produce pollutants that probably contain heavy metals. The heavy metals came into the river and accumulated in the sediment. This research was aimed to investigate the contains of Pb and Hg in the sediment of the Mati River. Determination of Pb and Hg content using AAS by standard addition method. Pb and Hg contents obtained were respectively 99,2 ± 0,0031 mg/kg and 142,8 ± 0,0648µg/kg. The concentration of Pb and Hg in the Mati River estuary is above threshold line.

KANDUNGAN TOTAL LOGAM Pb DALAM AIR DAN SEDIMEN SERTA BIOAVAILABILITASNYA DI PANTAI KEDONGANAN BALI Ni Gusti Ayu Made Dwi Adhi Suastuti; irdhawati Irdhawati; Nadya Sarilla Agatha
CAKRA KIMIA (Indonesian E-Journal of Applied Chemistry) Vol 9 No 2 (2021): Cakra Kimia (Indonesian E-Journal of Applied Chemistry)
Publisher : Graduate Program of Applied Chemistry, Udayana University, Bali-INDONESIA

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ABSTRAK: Pencemaran yang diakibatkan oleh logam berat dalam air laut dan sedimen sangat penting untuk diperhatikan karena dapat merusak lingkungan perairan dalam bentuk penurunan kualitas ekosistem. Tujuan penelitian ini untuk mengetahui kandungan total logam Pb dalam air dan sedimen serta bioavailabilitasnya di Pantai Kedonganan Bali. Penentuan kandungan logam Pb dalam air laut dan sedimen menggunakan Spektrofotometer Serapan Atom. Penentuan spesiasi logam Pb dalam sedimen dilakukan ekstraksi bertahap dan kandungan logamnya diukur menggunakan SSA. Konsentrasi logam Pb total dalam air laut adalah antara 0,2630-1,2642 mg/L pada tiga lokasi yang berbeda. Menurut Keputusan Kementerian Negara Lingkungan Hidup No.51 tahun 2004 tentang Baku Mutu Air Laut, keberadaan logam Pb di perairan sudah melewati ambang batas sebesar 0,05 mg/L. Konsentrasi logam Pb dalam sedimen sebesar 541,7 mg/kg. Berdasarkan pedoman mutu Australian and New Zealand Environment and Conservation Council (ANZECC) tahun 2000, konsentrasi logam Pb dalam sedimen sudah melewati nilai ambang batas yang telah ditentukan sebesar 50-220 mg/kg. Bioavailabilitas logam Pb didominasi oleh logam yang sifatnya berpotensi bioavailabel (46,42-53,58%), kemudian yang sifatnya non bioavailabel (37,92-39,46%), dan yang paling kecil adalah logam yang bersifat bioavailabel (7,36-15,35%). ABSTRACT: Monitoring of heavy metal pollution in seawater and sediment is very important because it can damage the aquatic environment in the form of decreasing ecosystem quality. The purpose of this study was to determine the total content of Pb in water and sediment in Kedonganan Beach Bali, and their bioavailability. Determination of Pb content in seawater and sediment has been done using Atomic Absorption Spectrophotometer (AAS). The speciation of Pb in sediments was carried out by stepwise extraction, then the Pb content was measured using AAS. The concentrations of total Pb in seawater from three different locations were between 0,2630-1,2642 mg/L. According to the Decree of the State Ministry of the Environment No. 51/2004 concerning Sea Water Quality Standards, the threshold for Pb in water over than acceptable value of 0.05 mg/L. The total concentration of Pb in the sediment was 541.7 mg/kg. Based on the quality guidelines of the Australian and New Zealand Environment and Conservation Council (ANZECC) 2000, the concentration of Pb was more than threshold value of 50-220 mg/kg. The potential bioavailability of Pb in sediment was 46.42-53.58%, followed by non-bioavailability at 37.92-39.46%, and bioavailable 7.36-15.35%.

ANALISIS LOGAM Cd (II) DENGAN METODE VOLTAMETRI PELUCUTAN ANODIK MENGGUNAKAN ELEKTRODA PASTA KARBON TERMODIFIKASI ZEOLIT ALAM Irdhawati Irdhawati; Ni Ketut Esati; Hery Suyanto
CAKRA KIMIA (Indonesian E-Journal of Applied Chemistry) Vol 4 No 2 (2016)
Publisher : Magister Program of Applied Chemistry, Udayana University, Bali-INDONESIA

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Pada penelitian ini telah dipelajari material zeolit alam teraktivasi asam sulfat 0,1 M yang digunakan sebagai modifier dalam elektroda kerja pasta karbon (EPK). Kinerja EPK termodifikasi zeolit alam teraktivasi asam (EPKZA) dibandingkan dengan EPK tanpa modifier dan penerapannya dalam penentuan kadar logam Cd(II) dalam sampel sayur dengan metode voltametri pelucutan anodik. Parameter optimasi yang diuji meliputi waktu deposisi dan laju pindai pada EPK dan EPKZA, serta komposisi zeolit dalam EPKZA. Komposisi elektroda kerja terbaik pada kondisi optimum pengukuran digunakan untuk menentukan rentang konsentrasi linier, limit deteksi, ketelitian, dan ketepatan penentuan logam Cd(II). Hasil yang diperoleh yaitu waktu deposisi 630 detikdan laju pindai 10 mV/s menggunakan EPK, dan komposisi modifier terbaik sebesar 5% dalam EPKZA, dengan waktu deposisi 540 detik dan laju pindai 20 mV/s. Rentang konsentrasi pengukuran EPKZA lebih luas yaitu dari 50-2000 ppb, sedangkan EPK tanpa modifier hanya memiliki rentang konsentrasi dari 100-1000 ppb. EPKZA dapat mengukur logam dengan konsentrasi yang lebih rendah dari EPK tanpa modifier, dengan batas deteksi pengukuran EPKZA adalah 58,41 ppb, sedangkan batas deteksi pengukuran EPK tanpa modifier sebesar 94,38 ppb. Keberulangan pengukuran larutan standar logamCd(II) dengan EPKZA menghasilkan nilai HorRat yang lebih kecil dari dua, serta nilai persen perolehan kembali sebesar 99,28±3,12 %, sehingga metode ini memiliki keseksamaan dan akurasi yang sangat baik. In this research the natural zeolite material activated by 0.1 M sulfuric acid was used as a modifier for carbon paste electrode (CPE). The performance of CPE modified by acid activated natural zeolite (CPEZ) was compared with CPE without modifier one and applied in the determination of Cd(II) concentration in vegetable samples using anodic stripping voltammetry method. The observed parameters includes deposition time and scan rate at CPE and CPEZ, and composition of modifier in CPEZ. The optimum composition and measurement condition of working electrode was used for determination linear range concentration, limit of detection, repeatability, and percent recovery. The result shows that the optimum deposition time are 630 s and 540 s, and scan rates are 10 mV/s and 20 mV/s for CPE and CPEZ respectively with the modifier concentration of 5%. The linear range concentration for CPEZ observed at 50-2000 ppb has wider range than CPE which was 100-1000 ppb. Limit of detection of CPEZ of 58.41 ppb is lower than CPE of 94.38 ppb. Determination of repeatability measurement of Cd(II) solution has HorRat value less than two, and percent recovery is 99.28+3.12%. Therefore, this method has a very good precision and accuracy.

SINTESIS KOPOLIMER CANGKOK KITOSAN-g-POLI(ASAM AKRILAT) SEBAGAI ADSORBEN KATION Cu2+, Pb2+, DAN Cr3+ James Sibarani; Arisma Damayanti; Irdhawati Irdhawati; Manuntun Manurung; Ni Made Puspawati
CAKRA KIMIA (Indonesian E-Journal of Applied Chemistry) Vol 6 No 2 (2018): Volume 6, Nomor 2, 2018
Publisher : Magister Program of Applied Chemistry, Udayana University, Bali-INDONESIA

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ABSTRAK. Sintesis dan karakterisasi kopolimer cangkok poli(asam akrilat) (PAA) pada kitosan (CS) {CS-g-PAA} sebagai penukar kation sudah dilakukan melalui kopolimerisasi redoks menggunakan cerium (IV)-sulfat sebagai inisiator. Konsentrasi dari monomer asam akrilat divariasikan pada konsentrasi 10%(v/v) dan 20% (v/v) dan juga variasi berat inisiator sebesar 0,1; 0,5; dan 1,0 gram. Data spektroskopi FTIR mengkonfirmasi keberhasilan proses grafting. Berdasarkan data spektroskopi FTIR, munculnya puncak serapan baru pada bilangan gelombang 1759,06 cm-1 (C=O).Persen grafting optimum diperoleh dan kopolimer yang disintesis menggunakan 0,5 gram cerium (IV) sulfat diperoleh sebesar 1066,18% (b/b) dan 2434,11% (b/b) berturut-turut untuk konsentrasi monomer 10% (v/v) dan 20% (v/v). pH optimum untuk adsorpsi Pb2+ dan Cr3+ adalah 6 sedangkan untuk yang diperoleh terhadap ion Cu2+ adalah pada pH 8. Kapasitas adsorpsi tertinggi yang diperoleh terhadap ion Cu2+ adalah 52,6 mg/g dan memungkinkan untuk meningkat. Tingginya kapasitas adsorpsi CS-g-PAA terhadap Cu2+ menunjukkan bahwa kopolimer ini merupakan penukar kation yang sangat baik Kata kunci: hidrogel, kopolimerisasi grafting, kitosan-g-poli(asam akrilat), penukar kation, redoks ABSTRACT. The synthesis and characterization of graft copolymer poly (acrylic acid) (PAA) in chitosan (CS) {CS-g-PAA) as cation exchanger were carried out by redox copolymerization using cerium (IV)-sulfate as an initiator. Concentrations of acrylic acid monomers were varied at concentrations of 10% (v/v) and 20%(v/v) as well as the variation of the initiator of 0.1; 0.5; and 1.0 gram. Analysis of the PAA was conducted using FTIR spectroscopy to confirm the process of grafting which revealed the existence of new absorption peak at 1759.06 cm-1 assigned to C = O. The optimum percentage of grafting and the synthesized of copolymer used 0.5 gram cerium (IV) sulfate were 1066,18%(b/b) and 2434,11%(b/b) respectively for the concentration of monomer in 10%(v/v) and 20%(v/v). The optimum pH for adsorption of Pb2+ and Cr3+ at 6, whereas for Cu2+ ion at pH 8. The highest adsorption capacity obtained on Cu2+ ions is 52.6 mg/g and that’s possible to increase. The higher capacity of CS-g-PAA adsorption to Cu2+ indicates that CS-g-PAA is an excellent cation exchanger.

TEKNIK VOLTAMETRI PELUCUTAN ANODIK UNTUK PENENTUAN KADAR LOGAM Cu(II) PADA AIR LAUT PELABUHAN BENOA Irdhawati Irdhawati; Emmy Sahara; I Wayan Hermawan
Jurnal Kimia (Journal of Chemistry) Vol. 10, No. 1 Januari 2016
Publisher : Program Studi Kimia, FMIPA, Universitas Udayana (Program of Study in Chemistry, Faculty of Mathematics and Natural Sciences, Udayana University), Bali, Indonesia

In this research, determination of Cu(II) using anodic stripping voltammetry were conducted by measuring the current peak of Cu(II) standard solution and the concentration of the metals in the seawater around Benoa Port. Deposition time and scan rate was optimized before validation. Parameters of the method validation examined were linear range concentration, limit of detection, repeatability, and % recovery. Seawater samples were collected from two different locations, which were Dermaga Ikan Tuna and Dermaga 2. The result showed the optimum deposition time and scan rate were 540 s and 7 mV/s. Linear range concentrations were 50 to 1000 ppb with correlation coefficient of 0,9998 and the detection limit of 29 ppb. Horwitz Ratio (HorRat) factor was obtained less than 2 for repeatability measurement and percent recovery was 100.58%. The concentration of Cu(II) was found to be 188 ppb in Dermaga Ikan Tuna and 117 ppb in Dermaga 2. The concentration of Cu(II) in the seawater around Benoa Port was higher than the treshold according to Ministry of Environment Regulation No. 51/2004 for Seawater Quality Standard.

Differential Pulse Voltammetry Technique Using Ferrocene-Modified Carbon Paste Electrodes for Determination of Pb(II) In Kepok Banana Irdhawati Irdhawati; Feby Silvia; Emmy Sahara; Nur Alisyah Gani
Jurnal Kimia Valensi Jurnal Kimia VALENSI Volume 6, No. 2, November 2020
Publisher : Syarif Hidayatullah State Islamic University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15408/jkv.v6i2.16610

The voltammetry method is a field of electrochemistry that measures electric current at a certain potential, which can be used to determine the concentration of inorganic and organic compounds that can be oxidized or reduced. In this research, the differential pulse voltammetry (DPV) technique has been used to determine the content of Pb(II). The carbon paste electrode (CPE) and ferrocene-modified carbon paste electrode (CPE-Fc) were used as working electrodes. This study aims to improve the sensitivity of Pb(II) measurement. Two parameters were optimized were ferrocene composition and scan rate. The validation parameters involved the linear concentration range, detection limit, quantization limit, precision and accuracy. The optimum ferrocene composition was found at 6%, and scan rate was 15 mV/s using CPE, increase to 20 mV/s using CPE-Fc. The validation results showed the linearity using CPE-Fc wider than CPE at the peak potential of 0.515 V. The detection and quantization limit values using CPE were 0.1551 µg/L and 0.1556 µg/L, and down to 0.1089 µg/L and 0.1090 µg/L using CPE-Fc. The precision determination for both of CPE and CPE-Fc had good results, indicated by the Horwitz ratio less than two. Percentage of recovery using CPE-Fc of 85.59 8.18%. CPE-Fc at the optimum measurement conditions was used to determine the levels of Pb(II) in kepok banana, and the result was obtained 4.4306 0.0009 mg/kg. The level of Pb content was found to exceed the established threshold based on Standard National Indonesia (ISN) No. 7387:2009 which is 0.5 mg/kg.

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