Jurnal Pendidikan Kimia
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An Optimization of Functional Monomer, A Preliminary Study of Meropenem Imprinted Polymer as Selective Sorbent
Get PDFMolecularly imprinted polymer is a polymer that synthesized together with targeted molecule (analyte) through polymerization process. When the polymerization has completed, extraction is taken to pull the analyte out of the polymer, and it will give a specific “frame” of targeted molecule which leave cavities and further is used to give specific recognition of the analyte. Functional monomer, template molecule, crosslinker agent, porogenic solvent and initiator are the main components involved in the synthesis of this kind of polymer. The right functional monomer is needed to make polymer building block with high selectivity when used as sorbent. The selection of suitable and precise functional monomer has been elaborated in this study. methacrylate acid, itaconic acid and acrylamide is then studies as functional monomer that will be chosen to give the best polymer performance as sorbent. From IR spectrum results, it can be concluded that polymer has been synthesized successfully. Peak at 1157 cm-1 which is a peak of C-N bond from β-lactam ring support this statement. Finally, it can be concluded that methacrylate acid is the best functional monomer for making polymer as sorbent for meropene
Acid Base Indicator from Shoot-Leaves Ethanol Extract of Pucuk Merah (Syzygium oleana)
Get PDFExperiment on natural acid-base indicators is usually done by extracting the natural sources with certain solvent, testing the extract with acid, base and neutral solutions, observing the color changes, making conclusion and discharging the remaining extract at the end of the experiment. Production of long-lasting natural acid-base indicator is needed to reduce the discharged of chemicals excessively. This research was carried out to produce natural acid-base indicator from extract of shoot leaves of Syzygium oleana (SLS). The extraction was done by maceration technique using ethanol 95% for 13 h. The extract of SLS (SLS indicator solution) is then used to produce SLS indicator paper by soaking the filter paper in SLS indicator solution and followed by drying under shade. Both of the solution and paper indicators were tested for their color changes in pH solutions range of 1-13. Durability and performance of the indicator was investigated for 6 d. Absorbance of the indicator solution was measured under wavelength of 200-700 nm by using UV-Vis spectrophotometer. The results showed that, both of the indicators can be used as acid-base indicator; even it can be used to determine the pH range of solution. The color changes of SLS indicator in solution pH of 1-13 were pink-fade green-moss green-brown. Both of the indicators showed a good performance in their color change for 6 d of storage. Thus, the ethanol extract of SLS can be used as raw material to produce acid-base indicator
The Effect of pH and Concentration of KNO3 Solution to the Performance of Nd3+ Ion Selective Electrode Using HPMBP Ionophore
Get PDFThe phenyl-3-methyl-4-benzoyl-5-pyrazolone (HPMBP) synthesized and characterized as ionophore in potentiometric analysis of ion selective electrode method (ISE) with polytetrafluoroethylene (PTFE) as the supporting phase. The pH and concentration of the ionic strength adjuster (ISA) were varied to know at the optimum pH and concentration of the ion-selective electrode (ESI) KNO3, thus potential Nd3+ gives the best performance. Before use the PTFE membrane was immersed in a chloroform-HPMBP solution of 1.5-2.0% w/v for 24 h. The pH variation of the buffer solution was adjusted to the pH range of 2-10 using HCl and NaOH solutions, whereas the concentration of KNO3 varies from 10-1 to 10-3 M. The concentration range of Nd3+ is between 10-2 and 10-7 M. The electrode potential measurement results (ENd) obtained the best performance value at pH 4 with KNO3 concentration of 10-2 M, sensitivity (S) 18.39 ± 1.2 mV/decade and response time less than 23 s
Isolation of Ferulic Acid from Leaves of Mindi (Melia azedarach L.) and Its Antioxidant Activity Test
Get PDFMindi (Melia azedarach L.) is one of a plant from Meliaceae family and has been known for its bioactive compound, such as ferulic acid. On this study, the isolation of ferulic acid and antioxidant activity test has been conducted. The aim of this study was to isolate the ferulic acid on ethanol extract of Melia azedarach L. leaves, determine the ferulic acid content and antioxidant activity test qualitatively. The method used in this research was isolation with hydrolysis (acid and base) and without hydrolysis, determining the phenolic acid content using TLC scanner instrument and antioxidant activity test qualitatively using DPPH radical reduction method. According to the identification using TLC and TLC scanner, the base hydrolysis fraction (HB), acid hydrolysis (HA), and without hydrolysis (HA) of ethanol extract from Melia azedarach L. was suspected contain the ferulic acid compound. The analysis result using TLC scanner was known to have ferulic acid content on HB, HA, and TH fraction of 15.57%,12.17%, and 9.56%, respectively. This study showed that hydrolysis affected the phenolic acid content where the HB fraction produced higher ferulic acid than HA and TH fraction. The antioxidant activity test that has been conducted qualitatively showed that ferulic acid isolates contained on each fraction actively reduce the DPPH radical
Study of Adsorption Capacity of Dibenzotiofen Molecules on Mesoporous Carbon with Pore Geometry Model
Get PDFAdsorption models in a simple and accurate way to describe the geometry of the pores have been studied and validated experimentally to predict the adsorption capacity dibenzotiofen molecules on mesoporous carbon. The model is designed according to the size of the pore channels of mesoporous carbon and molecular arrangement dibenzotiofen that goes into the pores. To test the accuracy of the model is done by comparation with results of analysis of nitrogen adsorption-desorption to calculate the volume filled. The results showed that the results of the experimental adsorption data are within the range of values of the pore volume of mesoporous carbon. These results indicate that the pore geometry model molecule can accurately predict the adsorption capacity of a molecule in a mesoporous material.
Influence of Silicate and Calcium Ions to Transport of Phosphate Ion through Polymeric Inclusion Membrane (PIM)
Get PDFMeasurement of phosphate ions by molybdenum blue method is influenced by the presence of interfering ions, such as silicate and calcium ions. To obtain an accurate measurement, interference ions should be separated from the phosphate ion. Separation could be carried out with extractions using PIM method. The effectiveness of separation based on PIM method depends to the transport efficiency of targeted ion from feed phase to stripping phase. The aim of this research was to determine the effect of silicate and calcium ions to phosphate ion transport through PIM. PIM was prepared by mixing PVC as polymer, 1,10-dekanadiol as a plasticizer, and Aliquat 336-Cl as extractant in the solvent THF. Extraction was performed by using a diffusion cell, The cell was consisted by two containers, i.e feed phase container and stripping phase container which was separated by PIM. Feed phase was a mixture of phosphate 100 mg / L and SiO32- at 5; 10; 15; 20 and 25 mg/L for studying the effect of silicate ion. Investigation of calcium ion effect was conducted by using a mixture of phosphate solution of 100 mg / L and Ca2+ of 1.13x10-4; 2.26x10-4 and 4.52x10-4 mg/L in the feed phase. The stripping phase was the solution of NaCl 0.1 M. Both containers were stirred for 3 hours at 180 rpm. The solution in the both containers was taken for 1 mL every 30 minutes. Phosphate ion was measured by visible spectrophotometry at 690 nm with molybdenum blue method. Silicate ion was determined by visible spectrophotometry at a wavelength of 410 nm with molybdenum blue method. Calcium ion was determined by AAS. The results showed that the higher concentration of calcium ions, the lower the phosphate ion transport efficiency. Only 34.46% of phosphate ions transported in the presence of calcium ions up to 4,52x10-4 mg/L. Meanwhile, PIM was more selective to silicate ion than ion phosphate at the silicate ion concentration up to 15 mg/L. At higher concentration of silicate ions, PIM was more selective to phosphate ion
Strengthening the Competencies of Target Teacher in Assistance of Curriculum 2013 Implementation in Tanggamus Regency - Lampung Province
Get PDFDevelopment stage of curriculum 2013 has entered the limited-implementation phase to secondary schools. To maintain and improve the sustainability of the understanding and implementation of curriculum 2013, the government has programmed assistance activities for teachers and principals. This programs conducted as reinforcement in understanding the concept of Curriculum 2013 and to help overcome the obstacles that arise during the curriculum implementation. The research objective is to obtain information on the assistance of Curriculum 2013 implementation in accordance with the philosophy, concepts, rules, principles, meaning and procedures included in the elements of the curriculum changes based on Graduate Competence Standard (GCS), Core Competencies (CC) and Standard Competencies (SC) in Tanggamus regency, province of Lampung. The result of the research showed that there are the strengthening competency of target teacher during the mentoring conducted by the core/assistant teacher. The strengthening competencies includes the understanding of: 1) textbooks and teachers' manuals, 2) learning and assessment process, 3) the preparation of lesson plan, 4) learning implementation.
Implementation of Item Response Theory for Analysis of Test Items Quality and Students’ Ability in Chemistry
Get PDFThis first aim of this study is to describe the quality of chemistry test item made by teacher. The test was developed for 11th grade students’ science class in the first semester on academic year 2015/2016. The second aim of this study is to describe the characteristic of measurement’s result for students’ ability in chemistry. This is descriptive research design with the 101 student’s responses patterns from multiple choice test device with 5 answer alternatives. The responses patterns were collected by documentation technique and analyzed quantitatively using Item Response Theory software such as BILOG MG V3.0 with 1-PL, 2-PL, and 3-PL models. The differences of students’ ability in chemistry in model 1-PL, 2-PL, dan 3-PL were analyzed using One-Way Anova Repeated Measure. The result showed that the mean of item difficulties level (b), item differentiate (a), and pseudo-guessing (c) are good. The measurement tools arranged by teacher were suitable for students who have the ability from -1.0 to +1.7. The maximum score of item information function is 68.83 (SEM =0.121) with ability in 0.2 logit. The highest ability’s estimation score was showed by Model 2-PL. The mean of students’ ability for 11th grade students is -0.0185 logit and consider as moderate category.
Synthesis of Natural Ni/Zeolite Activated by Acid as Catalyst for Synthesis Biodiesel from Ketapang Seeds Oil
Get PDFThe purpose of this research are to know the effect of addition Ni on the acidity value of Ni/zeolite catalyst and to know the best combination nickel and Zeolit activated by acid as a catalyst ofthe cracking process during synthesis biodiesel from ketapang seed oil. The Ni/Zeolite catalysts were prepared by immersing the zeolite activated by HCl 4 M into Ni(NO3)2 solution with concentration variation of0%, 5%, and 10%. The catalysts were characterized using XRD, SEM and FTIR. The results showed that the more Ni the more acidity value of the catalyst. The best quality of biodiesel was synthesized using combination catalysts of 5% Ni/Zeolite activated by acid
Gasoline Production from Coconut Oil Using The Ni-MCM-41 and Co/Ni-MCM-41 Catalyst
Get PDFGasoline have been produced from coconut oil using MCM-41, NiMCM-41, and Co/NiMCM-41 catalyst. The acidity of catalyst was analysed by Fourier Transformation Infra-Red Spectroscopy (FTIR). The yields of cracking product were analysed by Gas Chromatography-Mass Spectroscopy (GC-MS). The catalyst of Co/NiMCM-41 has the highest acidity than MCM-41 and NiMCM-41. It is caused by the effect of adding d orbital from Co and Ni. This cracking process is batch system, and the catalyst pellets were made at the temperature of 400 ºC. The highest gasoline product was obtained using the Co/NiMCM-41 catalyst with 89.53 % w/w yield. The major liquid product from the cracking process using MCM-41, NiMCM-41, dan Co/NiMCM-41 catalysts were estimated as 1-octena, octane, nonane; 1-octene, 1-nonene, nonane; 1-octene, octane, nonane, respectively.