JKPK (Jurnal Kimia dan Pendidikan Kimia)
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Characteristic Study of the MCM-41 Modified with Zn by Direct Synthesis
Get PDFModification of MCM-41 with zinc (Zn) by direct synthesis has been attempted. The aims of this research were (i) to show morphology of MCM-41, (ii) to know the optimal ratio of Si/Zn in MCM-41 modification, and (iii) to know crystallinity and pore diameter of MCM-41 and MCM-41 modified by Zn. Zn metal added to MCM-41 matrix by direct synthesis used zinc nitrate as precursor with ratio Si/Zn variation. Zn added by direct synthesis to get larger diameter without changing the structure of MCM-41. Characterization of material was used XRD, FTIR, TEM, and N2 adsorption. Characterization of MCM-41 with TEM show that material has spherical shape with uniform pore morphology. The result of XRD show that synthesized MCM-41 has good crystallinity with three peaks observed specific to MCM-41. Ratio of Si/Zn optimal to modification MCM-41 is Si/Zn= 100. Modified MCM-41 show decrease in crystallinity and increase pore diameter that is 35.58 Ǻ compared with MCM-41 with pore diameter 31.42 Ǻ. Â
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
Cellulose Compound of Cacao Waste and Chemical Composition of Cacao Vinegar with GC-MS Method
Get PDFPotential of cacao resources at Indonesian is very dependent on the production of cacao produced by farmers and plantation availability. However, the cacao processing results are still not optimal to increase the cacao production. This is due to the disruption of pests and the number of cacao farmers over land functions for fast growing plants. Processing cacao produced cacao waste and with the use of pyrolysis technology is able to cope with the accumulation of plantation waste. This combustion results in liquid smoke of cacao (cacao vinegar) into distillate, charcoal. This study used pyrolysis temperature between 100-500 °C. The aim of this research is to analyze the cocoa waste and the results are cellulose content 17,27%, lignin 52,02% and hemicellulose 19,56%. The results of GC-MS analysis for cacao vinegar of Distric Wajo are acetic acid, n butane, methyl ester, propanoic acid, butanoic acid, cyclopenanone, 2 methyl pyridine, acetyloxy 2 propanone, butyrolactone, tetrahydro 2 furan methanol, 2,3 dimethyl 2 cyclopentene 1 on and Mequinol. The water content of the charcoal of cacao shell from Wajo district is 3.42%. The analysis results of the bound carbon content of activated charcoal of cacao shell is 54.45%. The EDS analysis for cacao shell from Wajo district resulted in C: 61.12%, O: 36.65%, Si: 0.59%, P: 1.48% and Al: 0.17%. Utilization of cocoa shell waste using pyrolysis technology can reduce carbon emissions to the environment. So that the development of everything can continue and the sustainability of forest remain sustainable.Â
The Implementation of Problem-Solving Model Using Concept Mapping Strategy to Increase Students’ Interest and Learning Achievement at the Lintas-Minat Chemistry Class
Get PDFThis Classroom Action Research (CAR) aims to improve students’ interest and achievement in learning in the eleventh grade students of lintas-minat Chemistry 1 of SMA Negeri 2 Surakarta in academic year 2015/2016 by implementing the learning model of problem-solving using mapping concept strategy in buffer solution subject matter. This CAR was carried out in two cycles and in each cycle there was four stages consisting of action planning, action implementation, observation, and reflection. Data of interest aspect and attitude aspect of learning achievement were collected through observations, questionnaires, and interviews techniques. Data of knowledge aspect and skill aspect of learning achievement were collected using test and observation techniques, respectively. The research data were analyzed using qualitative descriptive technique. The results of this research can be concluded that the implementation of problem-solving learning model using concept mapping strategy can increase the eleventh grade students’ interest and achievement in the learning subject matter of buffer-solution at the Lintas-Minat Chemistry 1 class of SMA Negeri 2 Surakarta. The achievement percentage of students’ interest aspect in the first cycle is 55% and the second cycle increases to 80%. The learning achievement of knowledge aspects increases from 60% in cycle I to 80% in the second cycle. The learning achievement of attitude aspect (spirituality, honesty, responsibility, and cooperation) reached 100% in cycle I with unfinished cooperation indicator and 100% in cycle II with completed of cooperation attitude indicator. For learning achievement in skill aspect in cycle I has reached 100%
The Effectiveness of Blended Learning Oriented LKS with POGIL Strategy on High School Chemical Bond Subject
Get PDFThe rapid development of technology requires innovation in learning. One of the innovations is blended learning. The concept of blended learning is mixing of face-to-face learning model in the classroom with online learning. The blended learning will strengthen the conventional learning model conducted in the classroom through the development of education technology. Blended learning can be combined with constructivist and cooperative learning using POGIL strategy. POGIL contextual- based blended learning is suitable for chemical bonding subject because it has abstract characteristics involves atoms and electrons which are macroscopic, microscopic, and symbolic particles. The aim of this research is to create the effective student worksheet blended learning-based viewed from students pretest and posttest results. The development of model in student worksheet uses 4D models (four D models) from Thiagarajan which consists of 4 development stages: Define, Design, Develop, and Disseminate. Focus of this study was limited to the stage of develop. The data were collected using a test sheet in the form of pretest and posttest through a limited trial. The results of this research indicate that the usage of blended learning-based student worksheet is effective viewed from N-gain which was obtained as much as 86.67% of students achieving moderate criteria, 6.67% of students achieving high criteria, and 6.67% students reach low criteria
Activity of Anti-plasmodial and Cytotoxicity of Kapur Leaves (Harmsiopanax aculeatus, Harms) Potential Fraction (FG2, FG3 and FG4) Traditionally Used to Treat Malaria in Maluku Indonesia
Get PDFHarmsiopanax aculeatus, Harms, also known as kapur, have been traditionally used as medicinal plants to treat malaria in Maluku, Indonesia, although scientific evidence of the antimalarial active compounds of this plant has not been studied. This study was conducted to evaluate the anti-plasmodial and cytotoxicity activity of the active fraction of H. aculeatus leaves. The fractions tested were FG2, FG3 and FG4 obtained by separation of methanol extract using Vacuum Liquid Chromatography (VLC) by gradually using n-hexane, chloroform, ethyl acetate and methanol solvents. Anti-plasmodial activity in vitro was evaluated in Plasmodium falciparum strain FCR3 which is chloroquine resistant using microscopic method. The activity of cytotoxicity against vero cells was evaluated using MTT colorimetric method. The anti-plasmodial activity and cytotoxicity were expressed by IC50, inhibitory concentration of 50% Plasmodium or cells growth after incubation with the fraction tested, which calculated using probit regression analysis with SPSS. The results showed that the fraction of FG2, FG3 and FG4 had a promising anti-plasmodial activity with IC50 value of 7.48; 8.24 and 7.75 μg/mL, respectively. The cytotoxicity activity of the three fractions on vero cell were 5814.43; 7780.48 and 1022.44 μg/mL, respectively. Moreover, the selectivity index (IC50 Vero cells/IC50 Plasmodium) of those were 777.33,944.23 and 131.93, respectively indicated that the three fractions were active, non-toxic and selective against P. falciparum. Further study will be conducted to isolate the active compounds of the fraction
Validation of the TSH IRMA Kit for Determination of the TSH Levels in Human Blood Serum
Get PDFTSH IRMA kit is a kit used for the determination of TSH (Thyroid Stimulating Hormone) levels in human blood serum. Thyroid hormone is a hormone that our bodies need for growth of the brain, bone and other tissues and regulate the metabolism in the body. TSH normal range for adult is in the range of 0.4-4.5 mIU/L, whereas for baby is about 3.0-18.0 mIU/L. Thyroid would affect the quality of optimal growth of children if disturbed. Therefore, TSH assay in the blood needs to be determined to know whether the function of the thyroid gland works normally or not. Detection of TSH in blood can be performed by Immunoradiometricassay (IRMA) method. IRMA method is one of the immunoassay techniques based on immunological reactions (antigen-antibody binding) using radionuclide 125I as a tracer, that sample in small quantity can be detected.  IRMA method was developed locally by replacing TSH IRMA kit which is costly since imported from commercial companies. Center for Radioisotope and Radiopharmaceutical Technology (PTRR) BATAN has successfully developed the TSH IRMA kit that can be used to determine the levels of TSH in human blood. TSH IRMA kit must be validated to know the limit of detection, sensitivity, accuracy, precision and the assay parameters, such as Non-Specific Binding (NSB) and Maximum Binding (MB). Validation of TSH IRMA kit had been carried out resulting in the limit of detection of 0.115 ng/mL, accuracy with a recovery of 93.6-108.0 %, intra-assay precision (% CV) QC L = 1.9848, QC M = 3.6360 % and QC H = 2.2085 % while the inter-assay precision (% CV) QC L = 11.0055, QC M = 5.6768 % and QC H = 5.4181 %. It was concluded that this TSH IRMA kit showed good performance based on the % NSB and % B/T of 0.68 and 34.64 %, respectively
Optimization of Thyroglobulin Coated Tube for Thyroglobulin IRMA Kit
Get PDFImmunoradiometric assay (IRMA) is a method of analysis based on immunological reactions of antigens-antibodies binding. This highly specific and sensitive method was used for in vitro diagnosis in small quantity of sample. Center for Radioisotope and Radiopharmaceutical Technology, BATAN has developed Thyroglobulin IRMA Kit using coated tube method that can determine thyroglobulin levels in microgram quantities. Coated tube was made with immobilisation of anti thyroglobulin into polistyrene tube. Development of IRMA kit performed through several steps including: optimization component of kit, optimization assay and kit validation. Optimization of coated tube involved selection and volume of solvent, using blocking and non-blocking agent, and volume of blocking agent. The optimum condition for coated tubes was found to be using 0.1M phosphate buffer pH 7.4 with coating volume of 500 μL, 3% BSA in 500 μL blocking agent 0.1M phosphate buffer pH 7.4, with maximum binding and non-specific binding (NSB) of 60.58 and 1.40%, respectively. The optimized coated tube was found to be stable up to 4 weeks
Activity Test of Essential Lime Oil of Leaves, Twigs, and Rind against Escherichia coli and Bacillus cereus
Get PDFActivity tests of essential lime oil (Citrus hystrix DC) from its leaves, twigs, and rinds on the growth of gram-negative bacteria E. coli and gram-positive B. cereus have been conducted. Essential lime oil was obtained by steam distillation of leaves, twigs and rind for 5 h. GC-MS was used to analyze the composition of essential lime oil. Well diffusion method was used for antibacterial activities testing with concentrations of solution were 100, 300, 500 µL/mL in ethanol and microdilution method was used to determine the minimal inhibitory concentrations (MICs). The results showed that higher concentration of essential lime oil led higher minimal inhibitory in which minimal inhibitory of essential oil from rind was higher than that of leaves and twigs. MICs values of E. coli are 25, 50 and 12.5 µL/mL and of B. cereus are 6.25, 12.5 and 3.12 µL/mL of leaves, twigs and rind, respectively. Citronellal compound was found as main component of essential lime oil from leaves and twigs with value of 85.7 % and 46.4 %, respectively. In addition, sabinene (9.2%), β-pinene (21.4%), limonene (12.5%), citronellal (20.9%) and terpinene-4-ol (11.9%) were found as compounds of essential lime oil from rind