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Hasil Pencarian

Ditemukan 6 dokumen yang sesuai dengan query
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Arief Movadhy Rakhman
"Adduct merupakan zat hasil reaksi yang akan terbentuk dalam penggunaan zat pengalkil (alkylating agent) pada kemoterapi. N7-metilguanin merupakan adduct yang berkaitan erat dengan efektivitas zat pengalkil, sedangkan O6-metilguanin berkaitan erat dengan karsinogenisitas zat pengalkil. Pemisahan dan analisis kuantitatif campuran adduct tersebut berguna untuk memprediksi efektivitas dan karsinogenisitas suatu zat pengalkil. Penelitian ini bertujuan untuk mencari kondisi analisis dari campuran guanin, N7-metilguanin, adenin, O6-metilguanin, N1-metiladenin, dan N3-metiladenin, serta melakukan validasi atas metode analisis optimal tersebut. Metode yang digunakan ialah Kromatografi Cair Kinerja Tinggi (KCKT) dengan kolom penukar kation kuat Supelcosil LC-SCX dengan fase gerak amonium format-metanol (94:6) yang mengandung amonium format dengan konsentrasi akhir 30mM, pH 4, laju alir 1,2 ml/menit, suhu 30oC, dan detektor UV pada 274 nm. Persamaan kurva kalibrasi yang diperoleh menunjukkan hubungan linear dengan koefisien korelasi di atas 0,999. Batas deteksi dan batas kuantitasi untuk guanin dan N3-metiladenin berturut-turut ialah 0,1 dan 0,3 μg/ml, sedangkan untuk N7-metilguanin, adenin, O6-metilguanin, N1-metiladenin berturut-turut ialah 0,3 dan 0,5 μg/ml. Uji keterulangan pada keenam komponen sampel memberikan koefisien variasi di bawah 2%. Uji stabilitas menunjukkan koefisien variasi di bawah 2% pada pengujian selama 3 hari berturut-turut."
Depok: Universitas Indonesia, 2005
S32502
UI - Skripsi Membership  Universitas Indonesia Library
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Miftakhur Rohmah
"ABSTRAK
Lumpur Bledug Kuwu mengandung 0,0029 Li dalam bentuk fasa Li-Montmorillonit sehingga berpotensi sebagai deposit litium di Indonesia. Li-Montmorillonit dilindih menggunakan media akuades pada variasi rasio padatan/cairan 1/2, 1/5, 1/10 , temperatur 25oC, 30 oC, 35 oC, dan 45 oC , selama 2,3,4,dan 5 jam. Kondisi optimal adalah kondisi dengan kadar Li tertinggi dan rasio impuritas paling rendah, yaitu pada temperatur ruang selama 3 jam , rasio S/L = . Brine mengandung 15,11 ppm Li dengan rasio kadar Na/Li = 80,74 ; K/Li = 11,91 ; Ca/Li = 4,77 ; Mg/Li = 1,97. Semakin kecil rasio S/L maka perolehan kadar litium semakin kecil hingga 3,09 ppm dengan persen perolehan 92,71 . Semakin tinggi temperatur hingga 45oC maka perolehan litium semakin kecil hingga 9,29 ppm dengan persen perolehan 46,75 . Perolehan kadar litium meningkat seiring waktu pelindian namun mencapai maksimum setelah 3 jam dan kemudian menurun hingga 12,47 ppm dengan persen perolehan sebesar 69,67 . Hasil Uji XRD dan SEM mengonfirmasi bahwa Li-Montmorillonit telah berhasil dilarutkan dengan akuades pada semua kondisi pelindian. Selanjutnya, brine digunakan sebagai bahan baku pada tahap penguarangan kadar Mg dengan reagen batu kapur CaO . Penghilangan ion Mg dan Ca pada konsentrat menggunakan prinsip presipitasi kimia berdasarkan nilai kelarutan senyawa. Tahapan ini menghilangkan Mg hingga kadar akhir 0,02 ndash; 0,1 ppm. Semakin banyak jumlah CaO yang ditambahkan, semakin kecil kadar Mg dan B, namun kadar Li, Ca, dan K cenderung meningkat. Endapan dikonfirmasi oleh SEM-EDX dan XRD sebagai MgO. Kondisi optimal pada penambahan CaO sebesar 0,1875 gram ke dalam 100 ml brine. Reagen asam oksalat digunakan untuk membentuk presipitat Ca-Oksalat dengan adanya ion C2O42-. Namun, adanya ion HC2O4- dan H dapat meningkatkan kelarutan Ca-oksalat dalam larutan, sehingga kadar Ca semakin meningkat seiring penambahan asam oksalat. Reagen oksalat tidak stabil terhadap Li. Semakin banyak massa oksalat, litium mulai mengendap sebagai litium hidrogen oksalat hingga kadar Li berkurang menjadi 3,7119 ppm. Konsentrat 2 selanjutnya sebagai inluen pada proses pertukaran kation. Resin Lewatit S-108 dengan gugus aktif sulfonat hanya mampu mengadsorpsi fisika ion Li dan K, serta adsorpsi elektrostatik ion exchange ion Ca dalam kandungan inluen yang divariasikan pH 4, 6, dan 12 dan laju alir 50ml/0,5jam ; 50ml/1jam ;dan 50ml/2jam . Jumlah adsorpsi ion Li sebesar 0,0030 ndash; 0,0032 mmol/g, adsorpsi ion K sebesar 0,0027 ndash; 0,0028 mmol/g, adsorpsi ion Ca2 sebesar 0,0001 ndash; 0,0002 mmol/g, dan adsorpsi Na bernilai negatif. Semakin cepat laju alir, semakin tinggi juga efisiensi perolehan Li, Ca, dan K. Semakin tinggi pH mendekati basa , jumlah dan kapasitas maksimum adsorpsi Li, Ca, dan K.

ABSTRACT
The Bledug Kuwu rsquo s Mud contained 0,0029 Li in Li Montmorillonite phase form so that it could potentially be a lithium deposit in Indonesia. Li Montmorillonite was leached using water with variation of solid liquid ratio 1 2, 1 5, 1 10 , temperature 25oC, 30 oC, 35 oC, dan 45 oC , for 2, 3, 4, and 5 hour. The optimum leaching process was the condition that yield the highest Li content with the lowest impurity ratio. Water leaching at ambient temperature for 3 hours with the S L ratio of is the best condition. Brine contained 15,1086 ppm Li with content ratio of Na Li 80,74 K Li 11,91 Ca Li 4,77 Mg Li 1,97. The smaller the ratio of S L, the acquisition rate of lithium was the smaller until 3,0902 ppm with 92,71 of recovery. The increasing of temperature up to 45oC, the yield of litium was decreased until 9,29 ppm with 46,75 of recovery. The XRD and SEM results confirmed that Li Montmorillonite has been succesfully dissolved with aquadest under all condition of leaching process. Furthermore, Brine was used as a Raw Material at the removal stage of Mg content with a reagent of limestone solid CaO . The removal of Mg and Ca for concentrate used the principle of chemical precipitation based on the solubility of the compound. This reagent could remove Mg with an initial content of 29,76 ppm to concentrate with a final content of 0,02 ndash 0,1 ppm. The more CaO levels were added, the more Mg and B levels would decrease. While, the levels of Li, Ca, and K tend to increase. The phase of precipitate was confirmed by SEM EDX test as a cubic shaped MgO. The optimum condition concentrate 1 was obtained by adding CaO of 0,1875 gram into 100 ml Brine, so that final composition of lithium was 14,73 ppm. Oxalic acid reagents were used to form precipitates of Ca oxalate in the presence of C2O42 ions during ionization. However, the presence of HC2O4 and H ions could increase the solubility of Ca oxalate in solution, so that Ca content increased with the addition of oxalic acid. The oxalate reagent was unstable against the Li content, the more oxalate mass 4,7 grams added , the lithium began to settle as lithium hydrogen oxalate until the concentration of Li at Concentrate 2 decreases to 3,71 ppm. Concentrate 2 as an inluent in cation exchange process. Lewatit S 108 resin with sulfonate active group was only capable of adsorbing the physics of Li and K ions, as well as electrostatic adsorption ion exchange Ca ions in inluent content that varied on pH 4, 6, and 12 and flow rate 50ml 0,5hour 50ml 1hour and 50ml 2hour . The amount of Li ion adsorption is 0,003 0,0032 mmol g, adsorption of K ion 0,00274 ndash 0,00284 mmol g, Ca2 ion adsorption 0,0001 ndash 0,00022 mmol g, and Na adsorption is negative. The faster the flow rate, the higher the percentage recovery of Li, Ca, and K. While, the higher the pH near base , the maximum amount and the adsorption capacity of Li, Ca, and K. "
2018
T51641
UI - Tesis Membership  Universitas Indonesia Library
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"PEMISAHAN DAN ANALISIS 137Cs DARI LARUTAN PELAT ELEMEN BAKAR U-7%Mo/Al. Pemisahan cesium dari larutan pelat elemen bakar (PEB) U-7Mo/Al telah dilakukan dengan menggunakan metode pengendapan dan penukar kation. Tujuan penelitian adalah mendapatkan metode yang valid untuk pemisahan cesium dari larutan PEB U-7Mo/Al melalui penentuan parameter unjuk kerja metode yaitu akurasi, presisi dan rekoveri. Metode pengendapan dan metode penukar kation yang digunakan mengacu kepada metode ASTM 690-000 dan kepada hasil penelitian U3Si2/Al. Penentuan parameter unjuk kerja metode pengendapan dilakukan dengan menggunakan larutan sampel PEB U-7%Mo/Al sebanyak 150 μL, larutan standar 137Cs sebanyak 50 μL dalam 2 mL HCl 0,1N. Larutan dikenakan proses pengendapan dengan menggunakan pereaksi HClO4 pekat dan penambahan senyawa carrier CsNO3 seberat 225 mg pada temperatur 0oC selama 1 jam, sedangkan proses penukar kation dilakukan dengan menggunakan resin zeolit Lampung sebanyak 400 mg. Proses penukar kation dilakukan secara batch dengan pengocokan selama 1 jam. Hasil proses pengendapan diperoleh endapan CsClO4 dan penukar kation diperoleh berupa padatan cesium - zeolit serta supernatan. Pengukuran dan analisis radionuklida137Cs dalam endapan CsClO4 dan padatan 137Cs-zeolit dilakukan dengan spektrometer gamma. Hasil pengukuran diperoleh nilai cacahan radionuklida 137Cs per detik (cps). Perhitungan rekoveri metode dilakukan dengan perbandingan nilai cacahan radionuklida 137Cs sebelum dan sesudah proses pemisahan. Hasil pemisahan radionuklida 137Cs dari larutan PEB U-7Mo/Al menggunakan metode pengendapan diperoleh rekoveri sebesar 95,56 % dengan akurasi dan presisi pengukuran masing-masing sebesar 0,375 % dan 1,875 %, sedangkan rekoveri pemisahan radionuklida 137Cs dengan metode penukar kation diperoleh rekoveri sebesar 26,73 %. Hal ini menunjukkan bahwa metode pengendapan lebih baik dari pada metode penukar kation untuk pemisahan 137Cs dari larutan bahan bakar PEB U-7Mo/Al.
SEPARATION OF CESIUM FROM U-7MO/AL FUEL PLATE SOLUTION HAS BEEN DONE BY USING PRECIPITATION METHOD AND CATION EXCHANGE. The aim of this research is to get a valid method of separating cesium from U-7Mo/Al fuel plate solution through determination of parameter of method (accuracy, precision, and recovery). Precipitation method and cation exchange method that are used refer to standard ASTM 690-000 and research result of U3Si2/Al. Parameter method determination has been done by using 150 μL sample (U-7%Mo/Al fuel plate solution, 50 μL of standard solution in 2 mL of HCl 0,1 N. The sample solution was undergone precipitation process by using HClO4 concentrated and 225 mg of CsNO3as carrier in tempherature 0oC for an hour, while exchange cation process was done by using 400 mg of resin zeolit Lampung. The analysis of 137Cs in CsClO4 and 137Cs - zeolit was done by gamma spectrometre. Determination of recovery method was done by comparing count value of 137Cs before and after separation process. Recovery of precipitation method was obtained 95.56 % with accuracy and precicion measurement of 0.375 % and 1.875 % respectively, while recovery of cation exchange method obtained 26.73 %. To sum up, the results show that precipitation method better than exchange cation method for separation 137Cs from U-7Mo/Al fuel plate solution."
Pusat Teknologi Bahan Bakar Nuklir BATAN, 2016
621 URANIA 22:3 (2016)
Artikel Jurnal  Universitas Indonesia Library
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Rani Salsabila
"Caffeic acid dapat dianggap sebagai natural anti-oxidant yang esensial Namun, rendahnya solubilitas dan stabilitas caffeic acid di berbagai macam pelarut membatasi applikasi pada industri. Sintesis dari alkyl ester caffeic acid sangat menguntungkan berdasarkan fungsi biologis maupun potensi aplikasinya. Salah satu turunan dari caffeic acid, caffeic acid phenethyl ester CAPE merupakan senyawa dengan banyak aktivitas biologis yang berguna. Metode untuk mensintesis CAPE adalah dengan esterifikasi menggunakan katalis ion exchange resin. Tahap pertama merupakan esterifikasi dari caffeic acid dengan metanol untuk memproduksi metil kafeat. Kondisi reaksi dan parameter kinetika untuk reaksi sintesis metil kafeat dengan methanol menggunakan cation-exchange resin sebagai katalis akan dianalisis dan produk metil kafeat dikonfirmasi menggunakan Ultra Peroformance Liquid Chromatography UPLC . Kondisi optimum dimana produk metil kafeat tertinggi dihasilkan adalah sebagi berikut: suhu reaksi 60 C dan waktu reaksi 4 jam. Kinetika reaksi diasumsikan menggunakan pseudo-homogenous first order model dan hubungan antara suhu dan forward rate constant menghasilkan energi aktivasi 51 kJ/mol. Hasil tersebut mengindikasikan bahwa cation-exchange resin memiliki aktivitas katalisis yang tinggi.

Caffeic acid CA could be considered as an important natural anti oxidant. However, the low solubility and stability of CA in various solvent is limiting the application in industry. It is advantageous to synthesize alkyl ester of caffeic acid based on both their biological function and potential application. One of the caffeic acid derivatives called caffeic acid phenethyl ester CAPE is a compound with numerous important biological activities. To synthesize CAPE one of the method used is catalyzed esterification of caffeic acid and phenethyl alcohol using ion exchange resin catalyst. The first step of the process is to perform esterification of caffeic acid and methanol to produce methyl caffeate MC . MC would then be used to produce CAPE in the presence of phenethyl alcohol. Herein, the reaction condition and kinetic parameters for the synthesis of MC using cation exchange resin as a catalyst were investigated, and the product was confirmed by ultra performance liquid chromatography UPLC . The highest yield of MC catalyzed by cation exchange resin attained under the optimum condition as follows reaction temperature of 60 C and a reaction time of 4 h. The esterification kinetics of CA and methanol is described by the pseudo homogenous first order model. The relationship between temperature and the forward rate constant gives activation energy of 51 kJ mol. These results indicated that cation exchange resin possesses high catalytic activity in the synthesis of MC, which is an efficient catalyst suitable for MC production."
Depok: Fakultas Teknik Universitas Indonesia, 2018
S-Pdf
UI - Skripsi Membership  Universitas Indonesia Library
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Aukrawut Seenuan
"ABSTRACT
There are many conventional technologies used for recovery of precious metals from wastewater, but most of them are chemical intensive and consume high energy. This paper focuses on silver recovery using bio-electrochemical system (BES), which basically consists of two separated chambers, the anode and cathode chamber. The anolyte, containing either acetate or glucose as substrate, was fed into the anode chamber, in which microorganisms were employed to produce electrons through anaerobic oxidation. The catholyte was a synthetic mixed metals solution containing silver Ag(I), copper Cu(II), and iron Fe(III), which acted as terminal electron acceptors. Two BES reactors, in which anion exchange membrane (AEM) and a cation exchange membrane (CEM) served as separators, were investigated. Experiments were conducted at different initial Fe(III) concentrations (10 mM and 20 mM), while the concentrations of Ag(I) (10 mM), and Cu(II) (1 mM), were kept constant. The silver recovery obtained in the CEM-based reactor (> 99%) was higher than that in AEM-based reactor (58-75%). However, diffusion of Ag(I), Fe(III), and Cu(II) through the CEM was unavoidable. In terms of power generation, a power density of 4515.63 mW/m3 was found in AEM-based reactor, which was higher than that in CEM-based reactor (1542.56 mW/m2). However, the substrate loss was found in the AEM-based reactor due to the transport of negative-charged organic matter through the AEM, which caused a fast decrease of cell voltage. This study successfully demonstrated the feasibility of using a bio-electrochemical system to recover silver coupled with power generation from a synthetic mixed metals solution."
Pathum Thani: Thammasat University, 2017
607 STA 22:4 (2017)
Artikel Jurnal  Universitas Indonesia Library
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Thammasat Printing House, 2017
670 STA
Majalah, Jurnal, Buletin  Universitas Indonesia Library