This study aimed to study the parameters, which affect the separation of gadolinium(III) from sam... more This study aimed to study the parameters, which affect the separation of gadolinium(III) from samarium(III) and determine extraction efficiency (%E) and stripping efficiency (%S). Parameter selection was made to design experiment using two-level factorial based on response concentration of gadolinium(III) maximum and samarium(III) minimum. A simulation sample of a mixture of gadolinium(III) and samarium(III) was mixed with an emulsion prepared from a mixture of di-2-ethylhexyl phosphoric acid (D2EHPA) or tributylphosphate (TBP) ligands extractant, surfactant and the internal phase. Then the extraction and stripping results were analyzed using ICP-AES. The results for %E and %S separation of gadolinium(III) from samarium(III) were 72.48% and 48.46%, respectively.
The voltammetry method offers fast, efficient and simple preparation for the detection of the sam... more The voltammetry method offers fast, efficient and simple preparation for the detection of the sample containing rare earth elements (REE). The combination of voltammetry with the experimental design provided more efficient analysis especially the solvent consumption. This study aims to determine the factors that have an optimum effect using the experimental design results on the analysis of Gadolinium (Gd) in acetonitrile by Differential pulse voltammetry. The tertabuthylammonium perchlorate (TBAP) was used as supporting electrolyte. The screening and optimization of the parameter were carried out by Plackett-Burman experimental design and Central Composite Design. The two significant parameters were obtained for the analysis of Gd in acetonitrile by Differential pulse voltammetry (DPV) which are TBAP concentration value 0.1166 M and deposition potential at -0.7929 V.
The development of the separation method has an essential role in developing science and technolo... more The development of the separation method has an essential role in developing science and technology for the separation and purification of an element or compound from other mixtures based on differences in physical and chemical properties. This research is more focused on the selection parameters of polystyrene-based resin production using diethylene triamine penta-acetate (DTPA) light, which used as a prototype for improved scale production. The Plackett-Burman design was used to select variables that have significant influence in Methylaminopolystyrene-Diethylenetriaminepentaacetate (MAP-DTPA) resin synthesis. Eleven variables such as mol ratio of Methylamino Polystyrene and diethylene triamine penta-acetate ligands, solvent volume, reaction time, stirring rate, reaction temperature, total volume, reaction pH, incubation time, ammonia concentration, and the addition of methanol were carried out for the selection of parameters or variables in the process of MAP-DTPA resin synthesis...
Epithelial sodium channel (ENaC) is a transmembrane protein that has an essential role in maintai... more Epithelial sodium channel (ENaC) is a transmembrane protein that has an essential role in maintaining the levels of sodium in blood plasma. A person with a family history of hypertension has a high enough amount of ENaC protein in the kidneys or other organs, so that the ENaC protein acts as a marker that a person is susceptible to hypertension. An aptasensor involves aptamers, which are oligonucleotides that function similar to antibodies, as sensing elements. An electrochemical aptasensor for the detection of ENaC was developed using a screen-printed carbon electrode (SPCE) which was modified by electrodeposition of cerium oxide (CeO 2 ). The aptamer immobilization was via the streptavidin–biotin system. The measurement of changes in current of the active redox [Fe(CN) 6 ] 3−/4− was carried out by differential pulse voltammetry. The surfaces of SPCE and SPCE/CeO 2 were characterized using scanning electron microscopy, voltammetry and electrochemical impedance spectroscopy. The Box...
Kromatografi pertukaran ion telah digunakan secara luas dalam proses pemisahan dan pemurnian. Res... more Kromatografi pertukaran ion telah digunakan secara luas dalam proses pemisahan dan pemurnian. Resin penukar ion komersial sebagai fasa diam pada umumnya berbasis polistiren. Pada penelitian ini dikaji pembuatan resin penukar kation dengan gugus sulfonat yang diikatkan pada selulosa dari serat batang pisang sebagai limbah pertanian. Pembuatan resin penukar kation diawali dengan proses isolasi selulosa dari serat batang pisang, kemudian proses fosforilasi menggunakan fosfor oksiklorida 16,67% dalam metilen klorida (1:5), dan karakterisasi resin selulosa fosfonat menggunakan spektrofotometer inframerah, XRF, uji kapasitas pertukaran ion dan efisiensinya terhadap ion-ion Gadolinium (III), Neodimium (III), Serium (IV), Samarium (III), Praseodimium (III) dan Yttrium (III). Hasil penelitian menunjukkan kemurnian selulosa dari proses isolasi adalah 90,70% dan proses fosforilasi optimum pada suhu 90oC selama 2,5 jam. Karakterisasi dari spektrum inframerah menunjukkan adanya puncak baru, yait...
Rare-earth elements, which are important materials in numerous high technology applications, are ... more Rare-earth elements, which are important materials in numerous high technology applications, are relatively abundant in Indonesia, but have not been exploited for optimal economic benefit. One of our research group’s objectives of the studies on REEs is to develop extraction and chromatographic method(s) to prepare both mixture of REEs (or concentrates) and single rare-earth elements with sufficient purity, using di-n-butyldithiocarbamic (DBDTC) and with di-n-butyldithiophosphoric (DBDTP) acids as chelate-forming ligands. The complex formation reaction between each element under investigation (i.e. the rare-earth elements commonly constituting the minerals monazite and xenotime: Nd, Y, Ce, La, Gd) and each of the acidic ligands was studied for the first time. To prepare REEs concentrates, REE mineral samples were digested with different oxidizing reagents and experimental conditions. In one of the procedures, a mineral sample was digested with sulphuric acid, to produce REEs in thei...
Rare earth elements are a set of seventeen metallic elements, which is an essential part of many ... more Rare earth elements are a set of seventeen metallic elements, which is an essential part of many high-tech devices. Hence, analysis and/or separation of the rare earth elements from their mineral become crucial. A novel analysis method combining ultraviolet-visible spectroscopic and multivariate analysis was developed to determine middle rare earth elements quickly and simultaneously. The data collected from ultraviolet-visible spectroscopic were analyzed by multivariate analysis. The results showed that the developed method has good accuracy and precision with a detection limit of 1.375 (± 0.012), 0.332 (± 0.004), 42.117 (± 0.200), 1.767 (± 0.011), and 0.576 (± 0.002) ppm, respectively for samarium, europium, gadolinium, terbium, and dysprosium. The interference effect of ammonium iron(II) sulfate hexahydrate, manganese(III) sulfate hydrate, calcium carbonate, sodium carbonate, and lead(II) nitrate were examined. The reliability of the proposed method was evaluated using monazite s...
Indonesia merupakan salah satu negara penghasil timah terbesar di dunia dengan hasil sampingnya b... more Indonesia merupakan salah satu negara penghasil timah terbesar di dunia dengan hasil sampingnya berupa mineral ikutan, salah satunya adalah monasit yang mengandung lebih dari 50% logam tanah jarang (LTJ). LTJ memiliki kegunaan penting dalam berbagai teknologi dan memiliki nilai ekonomi yang tinggi. Banyaknya mineral monasit yang ditemukan di Indonesia, akibatnya Indonesia berpeluang dalam memproduksi dan memanfaatkan LTJ untuk penunjang kemajuan negara. Oleh karena itu diperlukan metode pemisahan yang tepat dan efisien untuk mendapatkan LTJ individu maupun campuran dalam bentuk murni, salah satunya yaitu metode pengendapan. Tujuan penelitian ini adalah memperoleh parameter pemisahan pada metode pengendapan yang berpengaruh terhadap respon yang berupa efisiensi pemisahan LTJ kelompok sedang dari kelompok LTJ lainnya berdasarkan desain eksperimen dari sampel LTJ hidroksida hasil olah monasit. Metode yang digunakan dalam penelitian ini adalah pengendapan selektif LTJ kelompok berat, se...
International Journal of Renewable Energy Development, 2020
Dysprosium has gained global interest due to its key application in renewable technology, such as... more Dysprosium has gained global interest due to its key application in renewable technology, such as wind power technology. The presence of this rare earth element (REE) can be determined by several spectroscopic methods. Recently, a voltammetry method has provided an alternative method for the simple and fast detection of REEs. However, to the best of our knowledge, this experiment is usually carried out in an aqueous solvent, and the response of the REE in an organic solvent by the voltammetry method has rarely been investigated. In this research, the quantitative detection of dysprosium and dysprosium mixtures with samarium, europium and gadolinium in acetonitrile is reported by differential pulse voltammetry. A Box-Behnken design was applied to predict the optimum condition of the measurements. Three factors, namely potential deposition, deposition time and amplitude modulation, were found to significantly influence the signal under optimal conditions, which are -1.0 V, 83.64 s and...
Gadolinium-mesoporous silica (Gd-MS) has been used widely as an alternative for synthesizing gado... more Gadolinium-mesoporous silica (Gd-MS) has been used widely as an alternative for synthesizing gadolinium-based Magnetic Resonance Imaging (MRI) contrast agents. In this study, Gd-MS was prepared by using the sol-gel method. Transmission Electron Microscopy (TEM) results gave an average pore size value of 38.184 nm, while the surface value of gadolinium mesoporous silica which is high at 580,666 nm. We describe the synthesis, characterization, and stability test of a novel type of magnetic nanoparticles based on Gd-Si oxide. The particles are nanosized and can enter cell easily. This is a completely novel biomedical application of mesoporous silica materials.
Abstract Metal oxide-based sensors have the advantage of rapid response and of high sensitivity t... more Abstract Metal oxide-based sensors have the advantage of rapid response and of high sensitivity to detect specific active biological species and are relatively inexpensive. This report of the present study concerns the development of a cerium oxide – monoclonal antibody bioconjugate for its application as a sensitive immunosensor to detect a breast cancer biomarker. A cerium oxide-anti HER2 bioconjugate was constructed by adding anti HER2 onto cerium oxide that had been previously reacted with APTMS and PEG-NHS-Maleimide. The FTIR spectra of the reaction product showed that the cerium oxide-anti HER2 bioconjugate was successfully synthesized. The resulted bioconjugate was then immobilized on a screen-printed carbon‑gold nanoparticles electrode surface by using the amine coupling bonding systems. The interaction of the synthesized cerium oxide-anti-HER2 bioconjugate with HER2 was found to inhibit an electron transfer and a decrease in the voltammetric Fe(CN)63-/4- peak current, which was proportional to the concentration of HER2. The optimal response of the current signal was generated at an anti-HER2 concentration of 5.0 μg/mL. The two linear ranges of HER2 concentration were found: that were 0.001 to 0.5 ng/mL and 0.5 to 20.0 ng/mL. By using the first calibration curve, the limit of detection was 34.9 pg/mL. The developed label-free immunosensor was used to determine HER2 in a human serum sample with satisfactory results, as shown by a consistent result with the addition of standard. Thus, the resulted immunosensor in this study is promising and has a potential application in clinical bio-analysis.
This study aimed to study the parameters, which affect the separation of gadolinium(III) from sam... more This study aimed to study the parameters, which affect the separation of gadolinium(III) from samarium(III) and determine extraction efficiency (%E) and stripping efficiency (%S). Parameter selection was made to design experiment using two-level factorial based on response concentration of gadolinium(III) maximum and samarium(III) minimum. A simulation sample of a mixture of gadolinium(III) and samarium(III) was mixed with an emulsion prepared from a mixture of di-2-ethylhexyl phosphoric acid (D2EHPA) or tributylphosphate (TBP) ligands extractant, surfactant and the internal phase. Then the extraction and stripping results were analyzed using ICP-AES. The results for %E and %S separation of gadolinium(III) from samarium(III) were 72.48% and 48.46%, respectively.
The voltammetry method offers fast, efficient and simple preparation for the detection of the sam... more The voltammetry method offers fast, efficient and simple preparation for the detection of the sample containing rare earth elements (REE). The combination of voltammetry with the experimental design provided more efficient analysis especially the solvent consumption. This study aims to determine the factors that have an optimum effect using the experimental design results on the analysis of Gadolinium (Gd) in acetonitrile by Differential pulse voltammetry. The tertabuthylammonium perchlorate (TBAP) was used as supporting electrolyte. The screening and optimization of the parameter were carried out by Plackett-Burman experimental design and Central Composite Design. The two significant parameters were obtained for the analysis of Gd in acetonitrile by Differential pulse voltammetry (DPV) which are TBAP concentration value 0.1166 M and deposition potential at -0.7929 V.
The development of the separation method has an essential role in developing science and technolo... more The development of the separation method has an essential role in developing science and technology for the separation and purification of an element or compound from other mixtures based on differences in physical and chemical properties. This research is more focused on the selection parameters of polystyrene-based resin production using diethylene triamine penta-acetate (DTPA) light, which used as a prototype for improved scale production. The Plackett-Burman design was used to select variables that have significant influence in Methylaminopolystyrene-Diethylenetriaminepentaacetate (MAP-DTPA) resin synthesis. Eleven variables such as mol ratio of Methylamino Polystyrene and diethylene triamine penta-acetate ligands, solvent volume, reaction time, stirring rate, reaction temperature, total volume, reaction pH, incubation time, ammonia concentration, and the addition of methanol were carried out for the selection of parameters or variables in the process of MAP-DTPA resin synthesis...
Epithelial sodium channel (ENaC) is a transmembrane protein that has an essential role in maintai... more Epithelial sodium channel (ENaC) is a transmembrane protein that has an essential role in maintaining the levels of sodium in blood plasma. A person with a family history of hypertension has a high enough amount of ENaC protein in the kidneys or other organs, so that the ENaC protein acts as a marker that a person is susceptible to hypertension. An aptasensor involves aptamers, which are oligonucleotides that function similar to antibodies, as sensing elements. An electrochemical aptasensor for the detection of ENaC was developed using a screen-printed carbon electrode (SPCE) which was modified by electrodeposition of cerium oxide (CeO 2 ). The aptamer immobilization was via the streptavidin–biotin system. The measurement of changes in current of the active redox [Fe(CN) 6 ] 3−/4− was carried out by differential pulse voltammetry. The surfaces of SPCE and SPCE/CeO 2 were characterized using scanning electron microscopy, voltammetry and electrochemical impedance spectroscopy. The Box...
Kromatografi pertukaran ion telah digunakan secara luas dalam proses pemisahan dan pemurnian. Res... more Kromatografi pertukaran ion telah digunakan secara luas dalam proses pemisahan dan pemurnian. Resin penukar ion komersial sebagai fasa diam pada umumnya berbasis polistiren. Pada penelitian ini dikaji pembuatan resin penukar kation dengan gugus sulfonat yang diikatkan pada selulosa dari serat batang pisang sebagai limbah pertanian. Pembuatan resin penukar kation diawali dengan proses isolasi selulosa dari serat batang pisang, kemudian proses fosforilasi menggunakan fosfor oksiklorida 16,67% dalam metilen klorida (1:5), dan karakterisasi resin selulosa fosfonat menggunakan spektrofotometer inframerah, XRF, uji kapasitas pertukaran ion dan efisiensinya terhadap ion-ion Gadolinium (III), Neodimium (III), Serium (IV), Samarium (III), Praseodimium (III) dan Yttrium (III). Hasil penelitian menunjukkan kemurnian selulosa dari proses isolasi adalah 90,70% dan proses fosforilasi optimum pada suhu 90oC selama 2,5 jam. Karakterisasi dari spektrum inframerah menunjukkan adanya puncak baru, yait...
Rare-earth elements, which are important materials in numerous high technology applications, are ... more Rare-earth elements, which are important materials in numerous high technology applications, are relatively abundant in Indonesia, but have not been exploited for optimal economic benefit. One of our research group’s objectives of the studies on REEs is to develop extraction and chromatographic method(s) to prepare both mixture of REEs (or concentrates) and single rare-earth elements with sufficient purity, using di-n-butyldithiocarbamic (DBDTC) and with di-n-butyldithiophosphoric (DBDTP) acids as chelate-forming ligands. The complex formation reaction between each element under investigation (i.e. the rare-earth elements commonly constituting the minerals monazite and xenotime: Nd, Y, Ce, La, Gd) and each of the acidic ligands was studied for the first time. To prepare REEs concentrates, REE mineral samples were digested with different oxidizing reagents and experimental conditions. In one of the procedures, a mineral sample was digested with sulphuric acid, to produce REEs in thei...
Rare earth elements are a set of seventeen metallic elements, which is an essential part of many ... more Rare earth elements are a set of seventeen metallic elements, which is an essential part of many high-tech devices. Hence, analysis and/or separation of the rare earth elements from their mineral become crucial. A novel analysis method combining ultraviolet-visible spectroscopic and multivariate analysis was developed to determine middle rare earth elements quickly and simultaneously. The data collected from ultraviolet-visible spectroscopic were analyzed by multivariate analysis. The results showed that the developed method has good accuracy and precision with a detection limit of 1.375 (± 0.012), 0.332 (± 0.004), 42.117 (± 0.200), 1.767 (± 0.011), and 0.576 (± 0.002) ppm, respectively for samarium, europium, gadolinium, terbium, and dysprosium. The interference effect of ammonium iron(II) sulfate hexahydrate, manganese(III) sulfate hydrate, calcium carbonate, sodium carbonate, and lead(II) nitrate were examined. The reliability of the proposed method was evaluated using monazite s...
Indonesia merupakan salah satu negara penghasil timah terbesar di dunia dengan hasil sampingnya b... more Indonesia merupakan salah satu negara penghasil timah terbesar di dunia dengan hasil sampingnya berupa mineral ikutan, salah satunya adalah monasit yang mengandung lebih dari 50% logam tanah jarang (LTJ). LTJ memiliki kegunaan penting dalam berbagai teknologi dan memiliki nilai ekonomi yang tinggi. Banyaknya mineral monasit yang ditemukan di Indonesia, akibatnya Indonesia berpeluang dalam memproduksi dan memanfaatkan LTJ untuk penunjang kemajuan negara. Oleh karena itu diperlukan metode pemisahan yang tepat dan efisien untuk mendapatkan LTJ individu maupun campuran dalam bentuk murni, salah satunya yaitu metode pengendapan. Tujuan penelitian ini adalah memperoleh parameter pemisahan pada metode pengendapan yang berpengaruh terhadap respon yang berupa efisiensi pemisahan LTJ kelompok sedang dari kelompok LTJ lainnya berdasarkan desain eksperimen dari sampel LTJ hidroksida hasil olah monasit. Metode yang digunakan dalam penelitian ini adalah pengendapan selektif LTJ kelompok berat, se...
International Journal of Renewable Energy Development, 2020
Dysprosium has gained global interest due to its key application in renewable technology, such as... more Dysprosium has gained global interest due to its key application in renewable technology, such as wind power technology. The presence of this rare earth element (REE) can be determined by several spectroscopic methods. Recently, a voltammetry method has provided an alternative method for the simple and fast detection of REEs. However, to the best of our knowledge, this experiment is usually carried out in an aqueous solvent, and the response of the REE in an organic solvent by the voltammetry method has rarely been investigated. In this research, the quantitative detection of dysprosium and dysprosium mixtures with samarium, europium and gadolinium in acetonitrile is reported by differential pulse voltammetry. A Box-Behnken design was applied to predict the optimum condition of the measurements. Three factors, namely potential deposition, deposition time and amplitude modulation, were found to significantly influence the signal under optimal conditions, which are -1.0 V, 83.64 s and...
Gadolinium-mesoporous silica (Gd-MS) has been used widely as an alternative for synthesizing gado... more Gadolinium-mesoporous silica (Gd-MS) has been used widely as an alternative for synthesizing gadolinium-based Magnetic Resonance Imaging (MRI) contrast agents. In this study, Gd-MS was prepared by using the sol-gel method. Transmission Electron Microscopy (TEM) results gave an average pore size value of 38.184 nm, while the surface value of gadolinium mesoporous silica which is high at 580,666 nm. We describe the synthesis, characterization, and stability test of a novel type of magnetic nanoparticles based on Gd-Si oxide. The particles are nanosized and can enter cell easily. This is a completely novel biomedical application of mesoporous silica materials.
Abstract Metal oxide-based sensors have the advantage of rapid response and of high sensitivity t... more Abstract Metal oxide-based sensors have the advantage of rapid response and of high sensitivity to detect specific active biological species and are relatively inexpensive. This report of the present study concerns the development of a cerium oxide – monoclonal antibody bioconjugate for its application as a sensitive immunosensor to detect a breast cancer biomarker. A cerium oxide-anti HER2 bioconjugate was constructed by adding anti HER2 onto cerium oxide that had been previously reacted with APTMS and PEG-NHS-Maleimide. The FTIR spectra of the reaction product showed that the cerium oxide-anti HER2 bioconjugate was successfully synthesized. The resulted bioconjugate was then immobilized on a screen-printed carbon‑gold nanoparticles electrode surface by using the amine coupling bonding systems. The interaction of the synthesized cerium oxide-anti-HER2 bioconjugate with HER2 was found to inhibit an electron transfer and a decrease in the voltammetric Fe(CN)63-/4- peak current, which was proportional to the concentration of HER2. The optimal response of the current signal was generated at an anti-HER2 concentration of 5.0 μg/mL. The two linear ranges of HER2 concentration were found: that were 0.001 to 0.5 ng/mL and 0.5 to 20.0 ng/mL. By using the first calibration curve, the limit of detection was 34.9 pg/mL. The developed label-free immunosensor was used to determine HER2 in a human serum sample with satisfactory results, as shown by a consistent result with the addition of standard. Thus, the resulted immunosensor in this study is promising and has a potential application in clinical bio-analysis.
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