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Wahyu Haryati Maser, Nancy Dewi Yuliana
Alchemy Jurnal Penelitian Kimia, Volume 13; https://doi.org/10.20961/alchemy.v13i2.4890

Abstract:
Kecombrang (Etlingera elatior) dikenal sebagai tanaman herbal di Indonesia yang umumnya digunakan untuk obat tradisional dan pemberi aroma pada masakan daerah. Tujuan dari penelitian ini adalah untuk mengidentifikasi waktu retensi yang merupakan komponen antibakteri Stapylococcus aureus yang berasal dari ekstrak bunga kecombrang (Etlingera elatior) dengan menggunakan metode metabolomik berbasis HPLC. Aktivitas antibakteri dari ekstrak etanol, fraksi kloroform, dan fraksi air telah diuji dengan metode difusi sumur terhadap pertumbuhan Stapylococcus aureus. Hanya pada fraksi kloroform yang menunjukkan adanya penghambatan terhadap pertumbuhan Staphylococcus aureus. Profil kimia dari fraksi yang dianalisis dengan HPLC telah dikorelasikan dengan profil aktivitas antibakteri dengan menggunakan analisis Orthogonal Projection to Latent Sructure (OPLS). Area puncak pada waktu retensi 0,96-1,12 menit dari fraksi kloroform pada panjang gelombang 250 nm ditemukan berkorelasi signifikan dengan aktivitas antibakteri (nilai Y related coefficient sebesar 0,73). Untuk identifikasi lebih lanjut komponen aktif tersebut, analisis LC-MS atau GC-MS dari fraksi yang mengandung puncak tertinggi diperlukan.
Eka Junaidi
Alchemy Jurnal Penelitian Kimia, Volume 13; https://doi.org/10.20961/alchemy.v13i2.5118

Abstract:
Asam galat merupakan salah satu bahan obat yang belum dapat diproduksi dalam jumlah besar di dalam negeri. Senyawa ini berperan sebagai bahan sintetis antioksidan dan antibakteri. Penelitian ini bertujuan untuk menghasilkan asam galat menggunakan limbah buah lokal di Pulau Lombok secara enzimatis. Terdapat 3 jenis limbah buah lokal yang digunakan yaitu kulit buah juwet, kulit buah kepundung dan kulit buah manggis. Hasil penelitian menunjukkan enzim yang digunakan adalah tanase dengan aktivitas sebesar 57,827 U/mg. Asam galat tertinggi diperoleh pada konsentrasi enzim tanase sebesar 1% dan waktu reaksi sebesar 60 menit untuk kulit buah kepundung sedangkan kulit buah manggis dan kulit buah juwet menghasilkan asam galat tertinggi pada konsentrasi enzim tanase sebesar 1,2% dengan waktu reaksi yang sama. Jenis kulit buah lokal yang paling baik sebagai penghasil asam galat adalah kulit buah kepundung.
Anak Agung Istri Ratnadewi Dewi, Moch Yoris Alidiona, Agung Budi Santoso, Ika Oktavianawatia
Alchemy Jurnal Penelitian Kimia, Volume 13; https://doi.org/10.20961/alchemy.v13i2.4356

Abstract:
Endo-β-1,4-D-xylanase is a hydrolytic enzyme that breakdown the 1.4 chain of xylan polysaccharide. We have succes to transform the plasmid pET-Endo gene encoding endo-1,4-β-D-xylanase from Bacillus sp. Originaly from termites abdominal to E. coli BL21. The clone was ready for large scale of enzyme production. To reduce porduction cost we look for subtitute medium for the expensive Luria Berthani broth. Chicken guts broth is good alternative while rich of protein and very cheap. Growth of E. Coli BL21 in Chicken guts broth and LB broth (as control) was observed by Optical Density (OD) with spectrofotometer. Concentration of glucose added in broth and incubation temperature was varied. The result showed that optimal growth was in addition of 1,5% glucose and incubated at 37 oC for 16 hours. This optimal condition was used for E. coli BL21 pET-Endo for xylanase production. Enzyme purification have done by Ni-NTA affinity chromatography. Highest protein yield was 0,076 mg/ml obtained in 100 mM imidazole elucidation. Xylanase characteization were : activity 0,042 U/ml, specific activity 0,556 U/ μg, purification factor 3,16 times and molecular weight ± 30.000 Dalton
Kiki Fransiska Suharto
Alchemy Jurnal Penelitian Kimia, Volume 13; https://doi.org/10.20961/alchemy.v13i2.5094

Abstract:
Tujuan dari penelitian ini adalah menentukan kandungan senyawa fenolik total dan kandungan isoflavon genistein selama fermentasi tempe hari ke 0 hingga 9. Ekstrak isoflavon diperoleh dengan metode maserasi dan fraksinasi. Kandungan total senyawa fenolik diukur dengan metode Folin ciocalteau dan kandungan isoflavon genistein ditentukan dengan menggunakan Kromatografi Cair Kinerja Tinggi. Data rendemen ekstrak isoflavon dan kandungan total senyawa fenolik dianalisa menggunakan Rancangan Acak Kelompok (RAK) dan purata antar perlakuan dibandingkan dengan uji Beda Nyata Jujur (BNJ) dengan tingkat kebermaknaan 5%. Kandungan senyawa fenolik total tertinggi selama proses fermentasi tempe diperoleh pada lama fermentasi hari ke 4 sebesar 232,05±7,71 μg/g, sedangkan kandungan isoflavon genistein tertinggi diperoleh pada lama fermentasi tempe hari ke 5 sebesar 100,48 μg/g. Proses fermentasi tempe menyebabkan kandungan senyawa fenolik total dan produksi isoflavon genistein bersifat fluktuatif.
Triana Kusumaningsih, Tri Martini, Lestari Okstafiyanti, Kartika Setia Rini
Alchemy Jurnal Penelitian Kimia, Volume 13; https://doi.org/10.20961/alchemy.v13i2.4320

Abstract:
The aim of the research is to determine the effective storage technique between the air cooling and vacuum cooling technique during storage process (0, 4, 8 and 12 weeks) and to increase the shelf life of kabocha pumpkin. Parameters measured during storage process were β-carotene and proximate content (water, pH, protein and sugar). β-carotene content was analyzed by Spectrophotometer UV-VIS followed by validation method, water content by Gravimetric method, pH by pH meter, protein by Makro Kjehldal method, and sugar by Luff Schrool method. The validation method showed good result which is proved by linearity, accuracy, precission, LOD, LOQ, and recovery values were 0.988, 98.8%, 3.39-7.73%, 0.011 ppm, 0.016 ppm, and 112% respectively. During storage process, β-carotene content was greater decreased on air cooling storage. For proximate content showed that water content was greater decreased on vacuum cooling storage. pH and the protein content was decreased on air cooling or vacuum cooling storage, but on air cooling was greater. Sugar content was increased during eight weeks and decreased on last week. From the result it can be seen that vacuum cooling storage was better technique for kabocha pumpkin. Keyword: β-carotene, air cooling, proximate, vacuum cooling
Karima Apriany,
Alchemy Jurnal Penelitian Kimia, Volume 13; https://doi.org/10.20961/alchemy.v13i2.2384

Abstract:
Guna meningkatkan nilai ekonomi dari konsentrat zirkon lokal dari Pulau Bangka, Cermet Ni-YSZ disintesis dari zirkonia yang sebelumnya telah disintesis dari konsentrat zirkon lokal. Cermet Ni-YSZ disintesis dengan menggunakan metode solid state reaction. Analisis XRD yang dilengkapi dengan refinement Le Bail telah dilakukan untuk menganalisis struktur kristal dan parameter sel dari material. YSZ dipreparasi dengan melakukan doping 8% mol yttrium oxide kedalam zirkonia dan kemudian disinter pada suhu 1250 oC selama 3 jam. ada penambahan doping 8% mol yttria memungkikan transfomasi fasa dari zirkonia dari tetragonal menjadi struktur kubik. Sementara itu, cermet Ni-YSZ memiliki fasa kristalin, Ni dengan struktur kubik dan YSZ dengan struktur kubik. analisis sem dari material-material tesebut menunjukan bahwa adanya penambahan Ni kedalam YSZ memungkinan morfologi menjadi lebih kasar dengan ukuran butir besar yang disebabkan adanya agglomerasi Ni terhadap YSZ. cermet Ni-YSZ memiliki konduktivitas tertinggi pada komposisi Ni:YSZ 20:80.
Muhamad Salman Fareza
Alchemy Jurnal Penelitian Kimia, Volume 13; https://doi.org/10.20961/alchemy.v13i2.8472

Abstract:
Penelitian ini bertujuan untuk mengevaluasi sifat antibakteri senyawa turunan asam sinamat dari rimpang kencur (Kaempheria galanga L.) yaitu etil p-metoksisinamat dan asam-p-metoksi sinamat. Etil p-metoksisinamat merupakan seyawa hasil isolasi yang diperoleh dari ekstrak n-heksan rimpang kencur. Pemisahan dan pemurnian snyawa tersebut dilakukan dengan menggunakan metode kromatografi cair vakum dan kromatografi kolom. Hidrolisis etil-p-metoksi sinamat dalam suasana basa menghasilkan asam-p-metoksi sinamat dengan rendemen 85%. Karakterisasi kedua senyawa dilakukan dengan menggunakan spektrofotometer NMR (1H-NMR dan 13C-NMR) dan spektrofotometer massa. Evaluasi sifat antibakteri kedua senyawa dilakukan dengan menggunakan metode mikrodilusi terhadap beberapa bakteri Gram-(+) dan Gram-(-). Senyawa yang didapatkan memperlihatkan sifat antibakteri yang lemah. Hanya etil p-metoksisinamat yang menunjukkan aktivitas antibakteri yang paling kuat khususnya terhadap bakteri Bacillus cereus dengan nilai MIC 62,5 µg/mL. Adanya perubahan gugus fungsi tampaknya tidak terlalu memberikan pengaruh signifikan terhadap peningkatan aktivitas antibakterinya.
, Rochmadi Rochmadi
Alchemy Jurnal Penelitian Kimia, Volume 13; https://doi.org/10.20961/alchemy.v13i2.5406

Abstract:
Tujuan penelitian ini adalah untuk mengetahui pengaruh perbedaan bahan penyalut terhadap efisiensi enkapsulasi oleoresin jahe merah dan analisis karakterisasinya. Proses enkapsulasi diawali dengan melarutkan kitosan dengan asam asetat 1% dan melarutkan sodium alginate menggunakan aquadest yang akan digunakan sebagai bahan penyalut. Oleoresin jahe merah dimasukan dalam larutan alginate kemudian diaduk, setelah itu masukan kedalam larutan kitosan dan diaduk kembali menggunakan homogenizer untuk membuat emulsi sambil ditambahkan tween 80. Emulsi yang terbentuk dimasukan dalam spray dryer untuk dikonversi menjadi bubuk mikrokapsul yang kemudian dihitung efisiensi enkapsulasi dan analisis morofologi mikrokapsul menggunakan scanning electron microscopy (SEM). Perbedaan bahan penyalut yang digunakan yaitu kitosan, campuran kitosan-alginat dan campuran kitosan-alginat-sodium tripolifosfat (STTP). Rasio berat oleoresin dengan bahan penyalut adalah 1:1, 1:2 dan 1:3. Hasil penelitian yang didapat yaitu efisiensi enkapsulasi tertinggi didapat pada bahan penyalut campuran kitosan-alginat-sodium tripolifosfat (STTP) pada rasio 1 : 3 yaitu sebesar 85%.
Monica Cahyaning Ratri
Alchemy Jurnal Penelitian Kimia, Volume 13; https://doi.org/10.20961/alchemy.v13i2.8916

Abstract:
ABSTRAK Pengembangan metode analisis surfaktan anionik natrium dodesil benzena sulfonat (SDBS) secara spektrofotometri UV-Vis menggunakan acridine orange (AO) dalam ikan lele telah dilakukan. Penelitian ini bertujuan untuk menentukan kondisi optimum analisis dan parameter validasi metode analisis dodesil benzena sulfonat (SDBS) dalam tubuh ikan lele. Penelitian ini dibagi dua tahap, yaitu isolasi natrium dodesil benzena sulfonat (SDBS) dalam tubuh ikan lele dengan ekstraksi Soxhlet dan analisis natrium dodesil benzena sulfonat (SDBS). Analisis natrium dodesil benzena sulfonat (SDBS) didasarkan pada pembentukan pasangan ion antara dodesil benzena sulfonat (DBS) dan acridine orange (AO). Hasil penelitian menunjukkan bahwa panjang gelombang maksimum pasangan ion dodesil benzena sulfonat (DBS) dan acridine orange (AO) adalah 499 nm, acridine orange (AO) larut dalam etanol, perbandingan mol dodesil benzena sulfonat (DBS) dan acridine orange (AO) adalah 2:1, dan pH optimum 2,97. Validasi metode menunjukkan nilai linearitas (r)0,998, batas deteksi 0,0343 mg/L, batas kuantifikasi 0,104 mg/L, presisi 0,382-1,78 %, sensitivitas 4,64 x 104 L mol-1cm-1 dan akurasi 82,11-100,3%.
Eddy Heraldy, Khoirina Dwi Nugrahaningtyas, Heriyanto Heriyanto
Alchemy Jurnal Penelitian Kimia, Volume 13; https://doi.org/10.20961/alchemy.v13i2.5606

Abstract:
The study of calcination treatment at 450°C on Ca-Mg-Al-hydrotalcite from brine water has been investigated. Characterization by XRD shows that Ca-Mg-Al hydrotalcite compound has found hydrotalcite phase and another phase such as Mg(OH)2, Al(OH)3 and CaCO3. These results are confirmed by the presence of hydroxyl groups, M-O and M-OH groups (M is Mg, Ca and Al) at wavenumber region around 3464.35 cm-1, 447.50 cm-1 and 531.41 cm-1. The calcination effect on Ca-Mg-Al hydrotalcite compounds at 450ºC being led to changes in structure become an metal oxide such as MgO, CaO, Al2O3, MgAl2O4 and CaCO3. These results are confirmed from decreasing on the absorption peak of M-OH group at wavenumbers region around 531.41 cm-1 and 786.99 cm-1 and widening of the absorption region at 500-900 cm-1. Consequently, the calcination treatment successfully increased the surface area of Ca-Mg-Al hydrotalcite compounds from 97.4 m2/g to 156.826 m2/g. Morphology of Ca-Mg-Al hydrotalcite changes the shape from a big to be small shape and the particle size distribution of 0-0.25 μm into 0-1 μm. Thermal analysis showed changes in the structure of hydrotalcite into oxide begins at a temperature of 265°C and started to become oxide completely after the temperature reaches 428°C.
, Endaruji Sedyadi, Sudarlin Sudarlin
Published: 8 April 2017
Alchemy Jurnal Penelitian Kimia, Volume 13; https://doi.org/10.20961/alchemy.v13i1.4350

Abstract:
The synthesis of chitosan–TiO2 film composite using sorbitol as plasticizer has been conducted. This research aims to develop environmental friendly plastic material which is safe for health due to the use of biodegradable chitosan - TiO2 that can block UV rays and therefore, maintain the quality of product from damage caused by UV rays. The anatase phase TiO2 nanocrystal was synthesized in chitosan matrix at room temperature and aging process. The solution was then added and blended in sorbitol for 24 hours to obtain homogeneous solution. The composite film was formed by coating method on a plate substrate, followed by drying. The characterization of film composite by XRD, TEM and FTIR showed the forming of anatase phase TiO2 nanocrystal that dispersed in chitosan matrix and formed the hydrogen bond. Meanwhile, from the physical properties characterization it was observed that the use of sorbitol as plasticizer had improved the plasticity tensile strength and elongation of the composite film. However, the excess sorbitol reduced the elasticity, tensile strength and elongation of the plastic. The best quality of plasticity obtained from film composite added by 3 % of sorbitol.
Yunita Arian Sani Anwar
Published: 8 April 2017
Alchemy Jurnal Penelitian Kimia, Volume 13, pp 17-28; https://doi.org/10.20961/alchemy.v13i1.4172

Abstract:
The aim of this study was to determine antioxidant activity of cashew apple dreg extract and their antioxidant activity in traditional processing of coconut oil. Cashew apple dreg was extracted by ethanol and fractionation by DCM, n-hexane and water. The antioxidant activity from dreg extract was determined using 2,2-diphenyl-1-pycrylhydrazil (DPPH). The result showed that all ethanol fractions of cashew apple dreg contain flavonoid and tannins/polyphenols. Based on scavenging DPPH all of ethanol fractions showed antioxidant activity. The greatest DPPH inhibition was observed for ethanol extract. On the contrary, n-hexane fraction showed the lowest IC50. Application in traditional processing of coconut oil showed that the addition 2,5% ethanol extract provide the best product according to the lower content of peroxide value and TBA number.
, Khabibi Khabibi, Rizka Nurfitriana
Published: 8 April 2017
Alchemy Jurnal Penelitian Kimia, Volume 13; https://doi.org/10.20961/alchemy.v13i1.4562

Abstract:
Research of chromium (VI) separation has been done using polymer inclusion membrane (PIM) method. This study aims to generate PIM, separate the metal ion chromium (VI) using PIM and determine the effect of the concentration of the feed phase, the thickness of the membrane and the amount of usage of the membrane for ion chromium (VI) diffusion.Polymer inclusion membrane (PIM) was made by mixing Aliquat 336-TBP as carrier compounds, PVC as the base polymer, DBE as a plasticizer and THF as a solvent. PIM membrane was placed between the source of analyte as a feed phase and result of the separation as a receiver phase. Feed phase was electroplating waste metal containing chromium (VI) at pH 4, while the receiver phase was a 2 N NaCl solution with a pH 6.7. The change of variables in this study were the concentration of the feed phase at various dilution i.e., 100x, 50x and 10x, the thickness of the membrane i.e., 25 μm, 20 μm and 10 μm, and the time of membrane using i.e., 1, 2 and 3 times. The concentration of chromium (VI) diffused after separation process was analyzed by atomic absorption spectroscopy (AAS). The stability of membrane was observed by analyzing the presence of membrane’s component in the feed phase and in the receiver phase. The analysis was conducted by UV-Vis spectrophotometry. Meanwhile, scanning electron microscopy (SEM) analysis was used to determine the morphology of membrane surface.The results showed that the chromium ion concentration diffused from the feed phase was 99.24%, meanwhile the 85.88% of it diffused to the receiving phase. The highest Cr(VI) ions diffusion was occured at the first use of PIM membrane with a thickness of 10 μm and the concentration of the feed phase was 10.55 ppm (resulted from 100 times dilution). Therefore, it can be concluded that the diffusion of chromium (VI) ion was influenced by the concentration of feed phase, the thickness of membrane and the number of membrane application.
, Arifah Khusnuryani, Khamidinal Khamidinal
Published: 8 April 2017
Alchemy Jurnal Penelitian Kimia, Volume 13; https://doi.org/10.20961/alchemy.v13i1.4324

Abstract:
The aims of this study was to synthesize a compound of 3-methoxy-4-hydroxychalcone through Claisen-Schmidt condensation with grinding technique (solvent-free). Vanillin, acetophenone and 60 % NaOH catalyst used in this synthesis. Characterization of products was done with a spectrophotometer FTIR and 1H-NMR spectrometer. The product was obtained as a orange solid which has a melting point at 58 - 59 ˚C. Identification of the product by IR spectrophotometer showed the absorption of C=C in the wavenumber of 1496.76 cm-1 which confirmed that the hydration reaction of chalcone had occurred. Analysis using 1H-NMR spectrometer also showed the proton of the CH=CH appearing on chemical shift (δ) 7.99 ppm. The antibacterial activity test showed that the compounds of 3-methoxy-4- hydroxychalcone has a potential as an antibacterial against bacteria E. coli and B. subtilis.
, Yana Maolana Syah,
Published: 8 April 2017
Alchemy Jurnal Penelitian Kimia, Volume 13; https://doi.org/10.20961/alchemy.v13i1.4232

Abstract:
In vitro antibacterial activity of chalcone derivatives from “temu kunci” (K. pandurta) rhizomes against clinical isolate bacteria has been done. Two chalcone derivatives, panduratin A (1) and 4-hydroxypanduratin A (2) were isolated from Kaempferia pandurata rhizomes. Isolation of the chemical components were done with extraction (maceration), vacuum liquid chromatography and radial chromatography methods. The structures were determined by NMR spectroscopy (1H-NMR, 13C-NMR, 1D and 2D), then compare with data from literatures. Antibacterial activity was carried out with reference to the CLSI microdilution method, against eight clinical isolate bacteria such as Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Enterobacter aerogenes, Pseudomonas aeruginosa, Salmonella typhi, Shigella dysentriae and Vibrio cholerae. Compounds 1 and 2 showed significant antibacterial activity with highest activity against S. aureus and B. subtilis with MIC values of 2.4 to 18.8 µg/mL and MBC values of 4.8 to 37.5 µg/mL. These results showed these compounds as potential antibacterial agent for clinical isolate bacteria.
Mutiara Nur Alfiah, Sri Hartini, Margareta Novian Cahyanti
Published: 8 April 2017
Alchemy Jurnal Penelitian Kimia, Volume 13; https://doi.org/10.20961/alchemy.v13i1.4326

Abstract:
This research aims to determine moisture sorption isotherm curves, moisture sorption isotherm models and thermodynamic properties of fermented cassava flour by red yeast rice. The moisture sorption isotherm model used are Guggenheim Anderson deBoer (GAB), Brunauer Emmet Teller (BET) and Caurie. Meanwhile, the test of modelling accuray by Mean Relative Deviation (MRD) and Root Mean Square Error (RMSE). The thermodynamic properties, i.e., enthalpy and entropy were calculated by Clausius - Clapeyron equation. The result shows that the moisture sorption isotherm curve on fermented cassava flour in a sigmoid form (type II). The GAB model is the best model for moisture sorption isotherm of fermented cassava flour by red yeast rice. The MRD and RMSE values at 30˚C, 35˚C and 40˚C are 3.12%, 2.71%, 3.81%, and 1.01, 0.35, 0.42, respectively. The monolayer moisture content at 30˚C, 35˚C and 40˚C are 6.61%, 6.27% and 6.91%, based on GAB model. Meanwhile, when the BET model was used, the monolayer moisture content are 4.92%, 4.86% and 5.19%, while by Caurie model are 6.37%, 6.18% and 5.30%, at 30˚C, 35˚C and 40˚C, respectively. The enthalpy and entropy of water sorption process were decreased when moisture content increased.
Maria Ulfa
Published: 8 April 2017
Alchemy Jurnal Penelitian Kimia, Volume 13; https://doi.org/10.20961/alchemy.v13i1.4070

Abstract:
Porous gelatin carbons (KPG) sample with micropores were synthesized from gelatin via templating method. This study analyzed microporosity using the Dubinin– Radushkevich (D-R) equation. The result shows that KPG sample has microporous type with empirical parameter n=2 which describing the homogeneous degree of KPG with the high order of micropore filling. D-R plot shows that the increasing the ratio of gelatin to SBA-15 led to the decreasing the microporosity of samples. However, this increases the size and pore volume due to the success of templating process.The result of TEM shows the carbon particle aggregation and FTIR result shows that carbon particle were dominated by the functional group of oxygen and hydrocarbon. The energy of adsorption range of 5-10 kJ/mol and a value of n=2 demonstrated that the adsorption of nitrogen on the porous gelatin carbon (KPG) physically occurred which is applicable to the next gas adsorption process.
, Priyo Wahyudi, Aniza Mutia Wardani, Dini Rohmatul Insani
Published: 8 April 2017
Alchemy Jurnal Penelitian Kimia, Volume 13, pp 52-65; https://doi.org/10.20961/alchemy.v13i1.2540

Abstract:
A group of protease enzymes such as papain and bromelain is able to decipher the molecular structure of the protein into amino acids which will be very useful in many fields, especially in food and pharmaceutical industries. The objective of this study to determine the molecular weight profile of enzyme bromelain from pineapple bark (Ananas comosus L. Merr) and papain (Carica papaya L.) from papaya latex with different varieties using sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) method. The precipitation was performed with ammonium sulfate ((NH4)2SO4)) 60 % addition and dialysized using a cellophane tubing with a pore size of 12,000 Dalton. The molecular weight of enzyme solution were determined using SDS-PAGE. The analysis results of molecular weight of enzyme bromelain of Subang and Bogor varieties were not different and were about 30.654 kDa, as well as the molecular weight of enzyme papain and Sukma California varieties were also not different and were about 23.485 kDa. It can be concluded that the different varieties of fruit of pineapple and papaya had no effect on the molecular weight of enzyme papain and bromelain.
, Hery Suyanto, Putu Yani Andani
Published: 8 April 2017
Alchemy Jurnal Penelitian Kimia, Volume 13; https://doi.org/10.20961/alchemy.v13i1.1808

Abstract:
In this research, the unmodified and modified carbon paste electrode with zeolite has been prepared, for determination of Cu(II) using anodic stripping voltammetry method. The parameters observed involved deposition time, scan rates, zeolite composition in carbon paste, and validation of working electrode. The optimum performance of carbon paste electrode modified with zeolite was applied for determination of Cu(II) in wastewater of the gong fabrication. The results of this research showed the optimum of deposition time and scan rates obtained at 410 s and 7.5 mV/s for unmodified carbon paste electrode, respectively. The optimum composition of zeolite-modifier is 20% from total graphite, with deposition time 380 s and scan rates 10 mV/s. The detection limit of the measurement of Cu(II) standard solution using unmodified carbon paste electrode is 46.13 ppb, is lower than unmodified carbon paste electrode, 99.93 ppb. Zeolite-modified carbon paste electrode has good precision and accuration. The concentration of Cu(II) in waste water of gong fabrication , using carbon paste electrode modified with zeolite is 93.54 ± 0.87 ppb.
, Irma Fadhila Putri, Eddy Heraldy
Published: 8 April 2017
Alchemy Jurnal Penelitian Kimia, Volume 13, pp 66-74; https://doi.org/10.20961/alchemy.v13i1.2378

Abstract:
This research was conducted to study the effect of catalyst type of CoMo/USY and the reaction time on the deoxygenation reaction of 4-methoxyphenol. The catalyst type used were CoMo/USY, Co-Mo/USY, and Mo-Co/USY. The product was analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). The activity of the Co-Mo/USY catalyst is higher than CoMo/USY and Mo-Co/USY, it can be seen from the value of total yield and the selectivity. The Co-Mo/USY catalysts shows a significant increasing on the total yield percentage (from 3.71 % to 9.41 %) during catalytic testing. The Co-Mo/USY catalyst has a highest selectivity toward 1,4-dimethoxybenzene product when the reaction time was one hour (0.92 %) and selectivity toward 1,4-dihidroxybenzene when reaction time two hours (0.43 %).
Ana Ulfa Istiqomah, , Khoirina Dwi Nugrahaningtyas
Published: 1 September 2016
Alchemy Jurnal Penelitian Kimia, Volume 12, pp 179-189; https://doi.org/10.20961/alchemy.v12i2.1876

Abstract:
Soda ash (NaOH) has been used in bioethanol production in the second step destillation to increase the purity up to 90%. The destillation process will produce waste water with a high sodium content. The soda ash itself serve as an electrolyte to modify the colligative properties of the water-ethanol mixture allowing the disappearance of azeotropic point. This research aims to study the replacement of NaOH with KOH, in which the kalium is a nutrient to maintain soil fertility. This research study the thermodynamics properties, vapor-liquid equilibrium, colligative properties and also its azeotropic point in the destillation of water-ethanol mixture when KOH and NaOH were used as the additive. A model of water-ethanol mixture at a various composition of 0-100 weight % of ethanol was used. The electrolyte addition was 0.1 mol electrolyte/total weight of ethanol-water. The result shows that the addition of electrolyte into ethanol-water mixture eliminate the azeotropic point and allows the ethanol molecules to separate from water. The enthalpy of mixing between water-ethanol is 239.601 kJ/mol. It becomes 259.796 kJ/mol and 264.793 kJ/mol after the addition of NaOH and KOH, respectively. It confirming the endothermic mixing process due to different polarity between water and ethanol. The presence of electrolyte even reduce more their molecular interaction. However, the change to irregularity result a high positive entropy values that result the negative Gibbs free energy. It confirms the spontaneity of mixing. The vaporization enthalpy, Hvap, of water-ethanol mixture is 76.229 kJ/mol and it becomes 235.366 kJ/mol and 126.189 kJ/mol after the addition of NaOH and KOH. It indicates that the presence of electrolyte inhibites vaporization of water as the major component and allowing ethanol molecules to vapor producing more high purity ethanol.
, Dian Maruto Widjonarko, Daryani Daryani, Yunita Haryanti
Published: 1 September 2016
Alchemy Jurnal Penelitian Kimia, Volume 12; https://doi.org/10.20961/alchemy.v12i2.1312

Abstract:
Telah dilakukan penelitian tentang lempung alam (bentonit) yang diaktivasi dengan berbagai variasi konsentrasi H2SO4, dan dengan proses interkalasi menggunakan larutan Al2O3.H2O. Tujuan dari penelitian ini adalah untuk menentukan konsentrasi optimum untuk aktivasi lempung, berdasarkan karakter persentase montmorillonite dan keasaman total. Hal ini juga didukung oleh karakterisasi setelah proses interkalasi, yaitu karakter luas permukaan spesifik, volume pori total, radius pori rata-rata dan kandungan aluminium. Analisis persentase-Montmorilonit dilakukan dengan menggunakan difraksi sinar X; keasaman total ditentukan secara gravimetri; luas permukaan spesifik, volume pori total, dan jari-jari pori rata-rata diukur dengan Surface Area Analyzer NOVA dan kandungan aluminium ditentukan oleh Analisis Aktivasi Neutron.Hasil penelitian menunjukkan bahwa aktivasi optimum pada konsentrasi H2SO4 1,5 M mempunyai persentase montmorillonite optimum (91.335%) dan nilai keasaman meningkat 193.955% dari nilai keasaman bentonit alam. Karakter fisik dan kimia setelah interkalasi juga menunjukkan bahwa terjadi peningkatan kadar aluminium (57,540%), luas permukaan spesifik (150,586%), volume total pori (73,236%) dan keasaman Total (203,504%) dari bentonit alam. Rerata jejari pori mengalami penurunan 10,274% setelah aktivasi dan penurunan 30,868% setelah proses interkalasi.
Rika Endara Safitri, Ani Mulyasuryani, Attasith Parnsubsakul, Patsamon Rijiravanich
Published: 1 September 2016
Alchemy Jurnal Penelitian Kimia, Volume 12, pp 128-141; https://doi.org/10.20961/alchemy.v12i2.1724

Abstract:
Metode deteksi Antigen Spesifik Prostat (ASP) berdasarkan pemotongan peptide dengan menggunakan perak enhancer (AgEhn) pada nanopartikel emas (AuNP) sebagai penanda. ASP merupakan serin protease yang dihasilkan secara normal oleh sel jaringan prostat dan sel kanker prostat.ASP secara luas digunakan sebagai biomarker untuk kanker prostat.Aktivitas ASP dideteksi berdasarkan pemotongan peptida yang terikat pada dasar wellplate melalui interaksi biotin – avidin. Setelah proses pemotongan, peptida-SH yang terpotong akan terbuang dalam proses pembilasan, peptidayang terpotong pada dasar wellplate tidak dapat mengikat nanopartikel emas karena kehilangan gugus tiol (-SH) pada ujung peptida. Sisa peptide-SH yang tidak terpotong akan berikatan dengan AuNP, diikuti dengan reduksi secara autokatalitik pada larutan AgEhn menjadi Ag(s). Jumlah Ag yang terdapat pada permukaan AuNP ditentukan secara voltametri lucutan anodik (VLA) setelah mengoksidasi Ag (s) menjadi ion Ag+ menggunakan elektroda screen printed carbon (SPC). Optimasi dilakukan pada kondisi pengukuran dan kondisi immunoassay, sehingga penentuan PSA pada rentang 1–500 ng.mL-1 dihasilkan limit deteksi sebesar 152,204 ng.mL-1 dengan sensitivitas 0,003 μ A/ng.mL-1. Penentuan PSA dengan metode ini telah berhasil dilakukan, namun masih membutuhkan kajian lebih lanjut.
Novi Anitra, Barlah Rumhayati, Catur Retnaningdyah
Published: 1 September 2016
Alchemy Jurnal Penelitian Kimia, Volume 12, pp 142-153; https://doi.org/10.20961/alchemy.v12i2.1390

Abstract:
Tujuan dari penelitian ini adalah mengevaluasi potensi sedimen perairan di wilayah reklamasi lumpur Lapindo sebagai sumber kontaminan logam berat (Pb, Cu, Zn) di badan air muara Sungai Porong, Kabupaten Sidoarjo. Evaluasi dilakukan dengan menentukan nilai faktor kontaminasi (Contamination Factor, CF) dan kode penilaian resiko (Risk Assessment Code, RAC) berdasarkan konsentrasi fraksi geokimia logam berat dalam sedimen. Fraksi logam berat ditentukan dengan metode ekstraksi bertahap (sequential extraction) BCR dimodifikasi oleh Chakraborty. Sampel sedimen diambil pada dua lokasi di muara Sungai Porong, yaitu pada lokasi 1 yaitu 7°34'26.76" LS, 112°52'53.76" BT dan lokasi 2 yaitu 7°33'31.35" LS, 112°51'05.56"BT. Sampel diambil dengan menggunakan Eickman Grab sampler, disimpan dalam wadah gelap pada suhu 40C. Konsentrasi logam berat ditentukan dengan Spektrofotometri Serapan Atom. Hasil penelitian menunjukkan bahwa pada kedua lokasi nilai CF(Cu) lebih tinggi dibandingkan CF(Pb) dan CF(Zn). Hal ini menunjukkan bahwa Cu memiliki waktu retensi lebih singkat dibandingkan kedua logam lainnya dalam sedimen. Dengan kata lain, Cu lebih mudah terlepas dari sedimen dan menuju badan air sehingga dapat mengkontaminasi badan air. Berdasarkan nilai RAC, sedimen di lokasi 2 memiliki potensi lebih besar melepaskan logam Cu dalam fraksi 1 (fraksi logam berat terlarut dalam air pori sedimen) dan fraksi 2 (fraksi logam berat mudah tertukar dan dalam bentuk karbonat) yang dapat dimanfaatkan langsung oleh biota di badan air. Dapat disimpulkan bahwa meskipun mangrove yang ditanam di wilayah reklamasi Lumpur Lapindo dapat mengabsorpsi logam berat tetapi sedimen perairan di wilayah tersebut memiliki potensi sebagai sumber kontaminan Cu, terutama di wilayah reklamasi yang berhubungan dengan laut.
Hartiwi Diastuti, Yana Maolana Syah, Lia Dewi Juliawaty, Marlia Singgih
Published: 1 September 2016
Alchemy Jurnal Penelitian Kimia, Volume 12; https://doi.org/10.20961/alchemy.v12i2.1726

Abstract:
The aim of this research was to isolate and indentify the terpenoid compound from Curcuma xanthorrhiza rhizomes and its antibacterial activity. Isolation was carried out by using vacuum liquid chromatography and centrifugal chromatography. The structure was determined by NMR spectroscopy (1H-NMR, 13C-NMR 1D and 2D), then compare with data from literatures. Antibacterial test was carried out by using microdillution methods and evaluated against eight bacteria. They are Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Enterobacter aerogenes, Pseudomonas aeruginosa, Salmonella typhi, Shigella dysentriae and Vibrio cholerae. The result showed that the isolate was a white crystal which was indetified as germacron-type sesquiterpene. Germacron have highest activity againts P. aeruginosa, MIC 15.6 µg/mL and MBC 31.2 µg/mL.
S Muljani, A Wulanawati
Published: 1 September 2016
Alchemy Jurnal Penelitian Kimia, Volume 12; https://doi.org/10.20961/alchemy.v12i2.1818

Abstract:
Microbial fuel cell (MFC) represents a major bioelectrochemical system that converts biomass spontaneously into electricity through the activity of microorganisms. The MFC consists of anode and cathode compartments. Microorganisms in MFC liberate electrons while the electron donor is consumed. The produced electron is transmitted to the anode surface, but the generated protons must pass through the proton exchange membrane (PEM) to reach the cathode compartment. PEM, as a key factor, affects electricity generation in MFCs. The study attempted to investigate if the sulfonated polystyrene (SPS) membrane can be used as a PEM in the application on MFC. SPS membrane has been characterized using Fourier transform infrared spectrophotometer (FTIR), scanning electron microscope (SEM) and conductivity. The result of the conductivity (σ) revealed that the membrane has a promising application for MFC.
, Achmad Bahrudin, Miftahul Anwar
Published: 1 September 2016
Alchemy Jurnal Penelitian Kimia, Volume 12, pp 167-177; https://doi.org/10.20961/alchemy.v12i2.708

Abstract:
Graphite as one alotrof carbon is widely used as an electrode material for a good electrical conductivity properties. Charcoal as a carbon source material was found very abundant in nature. Charcoal has the potential application for electrode material in energy storage such as in a battery or supercapacitor. For this purpose, charcoal amorphous structure needs to be converted into a graphite structure so that it has better electrical conductivity property. This research aims to prepare the electrical conductor material derived from wood charcoal that could potentially be used as an electrode. Preparation was made by mixing charcoal powder with asphalt binder with a weight ratio of 3:1, 4:1, 5:1 and followed by heat treatment under an inert atmosphere at temperature of 600°C, 800°C and 1000°C. Charcoal material which was originally to be an electrical insulator has been successfully converted into an electrical conductor. The achievement of the optimum temperature to produce electrodes with the smallest electrical resistance is then applied to the manufacture of carbon electrodes by heating a mixture of charcoal and fructose binder in a weight ratio of 1:1 (w/w). The results showed electrodes with a mixture of charcoal powder and fructose with heat treatment at 1000°C has the better electrical conductivity among other variations.
, Ariswan Ariswan, Dyah Purwaningsih
Published: 1 September 2016
Alchemy Jurnal Penelitian Kimia, Volume 12, pp 112-127; https://doi.org/10.20961/alchemy.v12i2.1744

Abstract:
Samples of vanadium- and -chromium doped TiO2-anatas have been conducted antibacterial activity against the bacteria Escherichia coli (E. Coli). The minimum kill concentration (MBC) against the bacteria of E. Coli is determined by liquid dilution method. The antibacterial activity test of 0; 2.3; 3.3; 4.9% wt. vanadium doped TiO2-anatas and 0; 1.1; 3.9; 4.4% wt. chromium doped TiO2-anatas have been performed against bacteria of E. Coli in the absence of light (dark). The test results indicate that the presence of 3.3 and 4.9 in %wt. vanadium-TiO2-anatas are able to inhibit the growth of bacteria E. Coli, contrary all chromium doped TiO2-anatas are not able to inhibit the growth of bacteria of E. Coli.
Rudiyansyah Rudiyansyah, Ajuk Sapar, Masriani Masriani
Published: 9 December 2015
Alchemy Jurnal Penelitian Kimia, Volume 11, pp 1-7; https://doi.org/10.20961/alchemy.v11i1.99

Abstract:
Erythro-carolignan E (1) has been obtained from the ethanol extract of the wood bark of Durio affinis Becc. This research was conducted in order to prove that conformational preferences of compound 1 were solvent dependent. On the basis of 1H-NMR data, the relative configuration of compound 1 was characterized by a coupling constant (3JHH) value of 3.3 Hz at H-7' in CDCl3. The coupling constant (3JHH) values of H-7' in compound 1 has changed to 4.1 Hz and 5.3 Hz in pyridine-d5 and acetonitrile-d3 respectively. As a result, the conformation of compound 1 at C7'-C8' has changed in different NMR solvents. In conclusion, structure oferythro-carolignan E that contains a dihydroxy group at C7'-C8' is able to change in different NMR solvent.
Chasanah Mazroatul, Glar Donia Deni, Nur Ahmad Habibi, Gita Febri Saputri
Published: 3 March 2016
Alchemy Jurnal Penelitian Kimia, Volume 12, pp 88-94; https://doi.org/10.20961/alchemy.v12i1.948

Abstract:
Hypercholesterolemia is a major cause of cardiovascular disease such as coronary heart disease. Betel water (Peperomia pellucida) is a type of plants that have antioxidant compounds that could delay, retard and prevent the oxidation of lipids, both enzymatic and non-enzymatic. This study aimed to determine the effect of ethanol extract Peperomia pellucida against total cholesterol, HDL, LDL, and triglycerides in the serum of white rats (Wistar) were given a diet aterogenetik, so it can be used as prevention of atherosclerosis. The active compounds contained in the water after screnning betel phytochemicals includes flavonoids, tannins, alkaloids, steroids and quinones. In vivo studies conducted by true experimental method with pre and post test with control group design. Rats were divided into 3 groups: group A positive control is given aterogenetik diet, group B and C were given diet Peperomia Pellucida aterogenetik and extract orally at a dose of 150 mg/kg and 300 mg/kg. Diet aterogenetik given as much as 20 grams per day for 14 days. Data obtained include total cholesterol, HDL, LDL, and triglycerides were analyzed by statistical methods Paired T Test oneway ANOVA (P < 0.05). The study of total cholesterol, HDL, LDL and triglycerides showed ethanol extract of Peperomia pellucida at a dose of 300 mg/kg body weight can lower total cholesterol and LDL significantly, but there was no significant decline in triglycerides and can increase HDL levels.
Khoirul Ngibad, Ani Mulyasuryani, Diah Mardiana
Published: 3 March 2016
Alchemy Jurnal Penelitian Kimia, Volume 12, pp 36-49; https://doi.org/10.20961/alchemy.v12i1.938

Abstract:
Electropolymerization of polypyrrole for determination of hydroquinone on screen printed carbon electrode (SPCE) was performed using cyclic voltammetry. Electropolymerization of polypyrrole on SPCE begins with determining the optimum conditions of cyclic voltammetry (working potential, scan rate, number of cycles) and the conditions of solution (pyrrole and KCl concentrations).The working potential were varied at 0 – 0.8; 0 – 0.9; 0 – 1 V. The variation of scan rate were 50, 100, 150 mV/s and number of cycleswere 5, 10,15 cycles. The influence of pyrrole concentration was studied by providing variation of 5, 50, 100 mM. Meanwhile, the KCl concentration were at 0.1; 0.5; 1 M. The SPCE modified with polypyrrole was washed with deionized water and was dried at room temperature. The prepared polypyrrole was analyzed and based on the high anodic and cathodic peak current of the hydroquinone, it is confirmed that the preparation was succefully conducted. The optimum conditions on electropolymerization of polypyrrole areat the working potential of 0 – 0.9 V; the scan rate 100 of mV/s; the number of cyclesis 10, and at thepyrroleconcentration of 50 mM and KCl concentration of 0.5 M. SPCE modified polypyrrole can determine the hydroquinone at the concentration range of 5 – 100 μM with the sensitivity of 0.120 μA/Μm and the detection limit (S/N = 3) of 0.8 μM.
Arenst Andreas Arie, Emerentina Maerilla Puspaningrum, Henky Muljana
Published: 3 March 2016
Alchemy Jurnal Penelitian Kimia, Volume 12, pp 61-69; https://doi.org/10.20961/alchemy.v12i1.944

Abstract:
Low-cost and environmental friendly activated carbons were synthesized from orange peel waste by carbonization followed by activation process using supercritical carbon dioxide. The carbonization process of orange peel waste was conducted in the electrical furnace at temperature of 800 °C for 2 h. Activation process of the impregnated orange peel was carried out in the tubular furnace for 1 h at activation temperature of 140 °C and pressure variation of 80, 125 and 170 bar. Activated carbon with highest surface area of 262.173 m2/g was obtained by co2 pressure of 125 bar. The activated carbons were then utilized as adsorbents for removal of methylene blue (MB) from aqueous solution. The batch adsorption study was carried out by varying the initial concentration of mb solution (2, 4, 6, 8 and 10 ppm). Experimental results showed that the adsorption kinetic of mb fitted the pseudo-second-order rate equation, where as for the adsorption isotherm model followed two models i.e. The dubinin- radushkevich and freundlich model. The adsorption mechanism was found to be governed by the intraparticle and surface diffusion mechanism.
Prapti Rahayu, Witri Wahyu Lestari
Published: 3 March 2016
Alchemy Jurnal Penelitian Kimia, Volume 12, pp 14-26; https://doi.org/10.20961/alchemy.v12i1.934

Abstract:
Metal-organic frameworks (MOFs) are porous coordination polymer containing bi-or polidentate organic linker coordinated with inorganic part, such as metal oxide cluster or metal cation as node which called as secondary building unit (SBU) to form infinite structure. Due to high porosity and surface area, good thermal stability as well as the availability of unsaturated metal center or the linker influence attracts the interaction with gases, thus MOFs have potential to be applied as hydrogen storage material. One type of MOFs that have been widely studied is [Zn4O(benzene-1,4-dicarboxylate)3], namely, MOF-5.Various synthesis method have been developed to obtain optimum results. Characterization of MOF-5 from various synthesis method such as crystallinity, capacity, stability, and quantum dot behavior of MOF-5 have been summarized in this review.
Ary Setyawan, M Fachri, A Sumarsono
Published: 3 March 2016
Alchemy Jurnal Penelitian Kimia, Volume 12, pp 95-102; https://doi.org/10.20961/alchemy.v12i1.950

Abstract:
Dammar Asphalt (Daspal) is expected to be used as a bio-asphalt renewable binder for road construction. It is made with a modification of the "Jabung", which is the dammar gum based material mixed with grounded red brick debris and low quality cooking oil at a certain ratio. Dammar gum is obtained from the Dipterocarpaceae family of trees in India and East Asia, most are produced by tapping trees. The gum varies in color from clear to pale yellow. Dammar gum is a triterpenoid resin, containing a large number of triterpenes and their oxidation products. Many of them are low molecular weight compounds. The objective of this research is to analyze the chemical properties of Daspal uses a Resonance Fourier Transform Infrared Spectroscopy (FTIR) method to compare with conventional asphalt. The investigation using spectral data showed that all types of Daspal have similar functional groups of Saturate, Aromatic, Resins, and Asphalten as the 60/70 penetration conventional bitumen, so that based on its chemical properties Daspal can be considered as bioaspal.
Intan Frina Utamiyanti, Barlah Rumhayati,
Published: 3 March 2016
Alchemy Jurnal Penelitian Kimia, Volume 12, pp 50-60; https://doi.org/10.20961/alchemy.v12i1.942

Abstract:
The development of material-based glucose sensor SiO2-CuO using Screen Printed Carbon Electrode (SPCE) had been done. Three types of materials were used to detect glucose, i.e Multi Wall Carbon Nanotube (MWCNT)-SiO2-CuO, SiO2-CuO (A) dan SiO2-CuO (B). The differences composition of SiO2-CuO(A) and SiO2-CuO(B) occurred during the addition of NaOH in synthesis process of SiO2-CuO (B). The prepared materials were analyzed by Scanning Electron Microscopy (SEM), cyclic voltammetry method and chrono-amperometry. Cyclic voltammetry analysis was conducted at a potential range of -1.0 - 1.5 V with Ag/AgCl as reference electrode. The scan rate was 100 mV/sec and the potential was varied at (-0.6), (-0.5) and (-0.4) V, in which the duration of each analysis was 5 second. Based on the result of analysis, whether by SEM, cyclic voltammetry and chrono-amperometry, the SiO2-CuO (B) was found to be the best material for detection of glucose.
Maria Erna, Emriadi Emriadi, Admin Alif, Syukri Arief
Published: 3 March 2016
Alchemy Jurnal Penelitian Kimia, Volume 12, pp 27-35; https://doi.org/10.20961/alchemy.v12i1.936

Abstract:
The thermodynamic properties and characterizations of corrosion inhibition of chitosan nano-particles on the surface of mild steel in peat water media had been studied using weight loss method at temperatures of 30 - 50 oC. Steel surfaces were characterized by FT-IR spectra and SEM-EDS morphology photos. The research found that the value of DGo approaching -40 kJmol-1. The negative value of Gibbs free energy shows that the adsorption of inhibitor molecules on the surface of mild steel was achemisorption and it occurred spontaneously. Meanwhile, the values of DHo is also negative confirming that the adsoprtion of inhibitor molecules is an exothermic process. The value of DSo obtained is positive, it indicates hat the inhibitor molecules were adsorbed spontaneously on the mild steel surface. The analysis on mild steel surfaces hows that the nano-particle chitosan was adsorbed on the steel surface to form the complex compounds.
Pramudita Putri Kusuma, Ganjar Fadillah, Husna Syaima,
Published: 3 March 2016
Alchemy Jurnal Penelitian Kimia, Volume 12, pp 1-13; https://doi.org/10.20961/alchemy.v12i1.930

Abstract:
The addition of garlic powder to gelatin from chicken claw waste was potentially developed as a natural preservative in food, especially for meat. Preparation of gelatin/garlic biocomposite was performed in three stages: synthesis of gelatin from chicken claw, garlic powder preparation as allicin source and preparation of biocomposite gelatin/garlic. The preparation of dry biocomposites was done by weighing the gelatin and garlic powder in weight ratio of 1 : 1 and 1 : 2 (w/w) in the total mass of 0.75 grams. For wet biocomposite preparation, the mixture of the powder was solved in 5 mL of lactic acid 2 %. Functional groups of gelatin, garlic and biocomposite were analyzed by fourier transform infrared spectroscopy (FTIR). The antibacterial activity of biocomposite against Staphylococcus aureus were tested using disc diffusion method. This test was performed on garlic powder, solvent and gelatin/garlic biocomposites powder in the ratio of 1 : 1 and 1 : 2 in 2 % lactic acid solvent. The biocomposite with a weight ratio of gelatin : garlic of 1 : 1 had the optimum diameter of inhibition zone. The effectiveness of biocomposite gelatin/garlic as natural preservative applied in meat was also physically studied by organoleptic analysis. Organoleptic analysis through the hedonic test was conducted on the parameters of color, smell, and texture of gelatin/garlic biocomposites-coated meat. The results showed that the addition of garlic can increase the effectiveness of gelatin as a natural preservative of meat for four days stored in closed packaging at room temperature.
, , Anna Rakhmawati
Published: 3 March 2016
Alchemy Jurnal Penelitian Kimia, Volume 12, pp 70-87; https://doi.org/10.20961/alchemy.v12i1.946

Abstract:
Bacterial cellulose (C) and its composites were synthesized from rice waste water with addition of glycerol (G) and chitosan (Ch).Antibacterial activity of the C, the bacterial cellulose-chitosan composite (CCh), and the bacterial cellulose – glycerol - chitosan composite (CGCh) which were deposited silver nanoparticles against S. aureus, E. coli, and yeast C. albicans has been conducted. Silver nanoparticles was prepared by chemical reduction of a silver nitrate solution, a trisodium citrate as a reductor, and a PVA as a stabilizer. The UV-Vis spectroscopy is used to determine the formation of silver nanoparticles. The characterization was conducted on the bacterial celluloses and those composites including the functional groups by the FTIR, the mechanical properties by Tensile Tester, photos surfaces by SEM, and the test of the antibacterial activity against S. aureus, E. coli, and C. albicans by diffusion method. The silver nanoparticle characterization indicates that the silver nanoparticles are formed at a wavelength of 418.80 nm. The antibacterial test showed an inhibitory effect of the C, the CCh, and the CGCh which are deposited the silver nanoparticles against of S. aureus, E. coli, and C.albicans. The CGChs which are deposited silver nanoparticles has the highest antimicrobial activity against the Staphylococcus aureus ATCC 25923. The CGs which are deposited silver nanoparticles provide the highest antimicrobial activity against the E. coli ATCC 25922 and the yeast Candida albicans ATCC 10231.
Irdhawati Irdhawati, Manuntun Manurung, Anisha Maulinasari
Published: 27 September 2016
Alchemy Jurnal Penelitian Kimia, Volume 11, pp 175-191; https://doi.org/10.20961/alchemy.v11i2.728

Abstract:
In this research, the modified carbon paste electrode with crown ether (dibenzo-18-crown-6) has been prepared, for determination of ascorbic acid. Some of parameters observed were optimization of crown ether composition in carbon paste, pH of solution, linear concentration range, limit of detection, reproducibility, and recovery. The optimum performance of the prepared electrode was applied for determination of commercialsampleswhich contain of ascorbic acid. The result of this research showsthat the optimum composition of crown ether in carbon paste is 0.6 % at pH 4. Linear range of concentration obtained is from 2 - 200 μM. The detection limit and percentage of recovery are 1.243 μM and 101.31 %, respectively. The modified electrode has HorRat value less than 2, it indicates a good reproducibility. Analysis of 4 commercial samples which contain of ascorbic acid were in agreement with the content listed in the label with the suitability of 94 - 100 %.
Khoirina Dwi Nugrahaningtyas, Eko Cahyono, Dian Maruto Widjonarko
Published: 27 September 2016
Alchemy Jurnal Penelitian Kimia, Volume 11, pp 111-126; https://doi.org/10.20961/alchemy.v11i2.712

Abstract:
This research deals with the study of the paraffin cracking reaction with termal reaction, active natural zeolite (ZAA) and NiMo / active natural zeolite (ZAA) catalyst. Temperature variation was done in order to study the optimum temperature of paraffin cracking reactions. Paraffin cracking reaction carried out at temperatures of 200 - 400 °C and a hydrogen flow rate of 30 mL / min. Cracking products obtained, and then analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry(GCMS). Catalyst activity (%) was defined as the amount of lighter fractions/the amount of feed (paraffin) (%). The results showed that the catalyst NiMo/ZAA has the highest activity (31.33 %) at the cracking reaction temperature of 300 ºC
Abdi Naufal Ramadhan, Luluil Maknun, Noerma Juli Azhari
Published: 27 September 2016
Alchemy Jurnal Penelitian Kimia, Volume 11, pp 192-199; https://doi.org/10.20961/alchemy.v11i2.724

Abstract:
The control of uric acid is important. A high level of uric acid can cause gout disease. Therefore a simple, fast, and accurate method for uric acid determination is required. In this research a conductometric biosensor has been developed by SPCE – Nata de coco for uric acid determination. The prepared biosensor was optimized to get a good performance of biosensor and it is applicable for human serum samples. The optimized variables were enzyme concentration, membrane thickness and pH solution. The various enzyme concentration were 6 μg/mL; 12 μg/mL; 18μg/mL; 24 μg/mL. The various membrane thickness were 5 μm; 10 μm; 15 μm. Meanwhile, the various pH solution were 7; 7.5; 8; 8.5; 9. The optimum enzime concentration was 18 µg/mL with the membrane thickness and pH were 5 µm and 8, respectively. The prepared biosensor can determine the uric acid concentration at range of 0 – 1.2 ppm with the sensitivity of 7.74 µS/ppm and the limit detection is 0 ppm. The biosensor was applied to uric acid detection in human serum with accuracy of 95 %.
Ganjar Fadilah, Pramudita Putri Kusuma,
Published: 27 September 2016
Alchemy Jurnal Penelitian Kimia, Volume 10, pp 195-206; https://doi.org/10.20961/alchemy.v10i2.544

Abstract:
Gelatin has been successfully extracted from chicken clawsby acid hydrolysis method through four major stages of degreasing, demineralization, extraction and drying. The yield of extracted gelatin obtained from wet chicken claws was about 6.21 % (w/w). The effectiveness of gelatin as preservative applied in beef and fish was physically, chemically and microbiologically studied by organoleptic analysis, peroxide test, bacteria inhibition test and number calculation, respectively. Organoleptic analysis by hedonic test shows there were significant differences for color and texture parameters between gelatin coated samples and control samples at concentrations of 1:1 (w/w). Peroxide number analysis by iodometry indicates the use of gelatin in the preservation of meat and fish decreased the oxidation number. The result of inhibition test againts Staphylococcus aureus bacteria shows the gelatin concentration of 20 % provided greatest halo zone diameter (inhibitory region) as 19.44 ± 2.11 mm. The colony bacteria test shows the use of gelatin potentially inhibited the growth of bacteria up to 75 %. Overall, the results conclude that gelatin extracted from chicken claws has the potential activities as a natural preservative for beef and fish.
Isya Fitria Andhika, Carissa Hertiningtyas, Ardian Aji, Alifia Desy, , Patiha Patiha
Published: 27 September 2016
Alchemy Jurnal Penelitian Kimia, Volume 10, pp 186-194; https://doi.org/10.20961/alchemy.v10i2.542

Abstract:
Fabrication with carbon-modified TiO2 by arc discharge method in liquid medium has been studied. This research was performed in two steps including fabrication and characterization. This fabrication was done by arcdischarge method with graphite electrodes from dry cell batteries and liquid medium suspension of TiO2 in ethanol 30, 50 and 70 %. A strong current was applied to electrode as 10 -50 A (20-40 V). Nanocomposites formed on the liquid medium surface were collected and characterized using X-ray diffraction (XRD),scanning electron microscope (SEM) dan energy dispersive spectroscopy (EDS) to determine crystallinity, surface morphology and the constituent elements, respectively. XRD data shows that the most effective fabrication TiO2/Karbon by liquid medium in ethanol 50 % indicated from the formation of a new peak with high intensity of TiC on 2Ɵ= 36.02 °. SEM data shows that the morphology of each aggregated TiO2/Karbon compared to the morphology of TiO2. In addition, EDS data shows the presence of the element carbon, titanium and oxygen in the same area indicating that the successful formation of composite material between TiO2 dan carbon.
Sentot Budi Rahardjo, Surya Dewi Marliyana, Nur Asih Siwi Wulandari
Published: 27 September 2016
Alchemy Jurnal Penelitian Kimia, Volume 10, pp 137-148; https://doi.org/10.20961/alchemy.v10i2.534

Abstract:
The purpose of the research is to find out the synthesis, formula and characteristic of complex of Nickel(II) with hydantoin (hyd). Complex of nickel(II) with hydantoin have been synthesized in 1 : 1 mole ratio of metal to ligan in methanol.The formula of complex which are predicted from analysis of % Ni in complex by Atomic Absorption Spectroscopy (AAS) is Ni(hyd)2(H2O)3.SO4. Ratio of cation and anion of complex is measured by conductivitymeter correspond to 1: 1. The thermal analysis is determined by Differential Thermal Analyser (DTA) indicate that complex contain some hydrate, thus possibility formula of complex is [Ni(hyd)2(H2O)2]SO4.H2O (Diaquadihydantoinnikel(II) sulfat monohidrat). Data of infra red spectra show a shift of N-H group and tertier N group 138 absorption and indicate this functional group coordinated to the center ion. Magnetic Suscepbility measurement show that the complex is paramagnetic with μeff = 3.2 BM. The UV-Vis spectra appear do to 2 transition peak on λ = 740 nm (13,513 cm-1) and 405 nm (24,691 cm-1). The peak indicate that structure of complex is octahedral with transition 3A2g→ 3T1g(P)(ν2) andtransition 3A2g → 3T1g(F)(ν3). One peak which is not appear is transition 3A2g → 3T2g (F)(ν1) which also estimate of 10 Dq (Δ0) is 103.615 kJ mol-1.
Desi Suci Handayani, Zainal Arifin Almaqqomul Amin, , Abu Masykur
Published: 27 September 2016
Alchemy Jurnal Penelitian Kimia, Volume 10, pp 49-53; https://doi.org/10.20961/alchemy.v10i1.730

Abstract:
Synthesis of C-hexyl calix[4]resorcinarene through condensation reaction between resorcinol and heptanal with HCl catalyst has been investigated. Synthesis conducted by the ratio of resorcinol: heptanal (1:1) using reflux for 6 hours in ethanol. Structural analysis of the product was done by FTIR and 1 H-NMR spectroscopy, while the characterization was done by determining melting point. The product was golden brown powder with a yield 99.43% and melting point more than 300 °C. Structural analysis with FTIR and 1 HNMR known vibration and signals characteristic of calix[4]resorcinarena group, the vibrations of the CH bridge. Vibration of CH bridge appearance at wave number 1445 cm-1 and 1456 cm-1, while signal of CH bridge appearance at chemical shifts from 4.17 to 4.21 ppm.
Khoirina Dwi Nugrahaningtyas, Yuniawan Hidayat, Tiara Diah Saputri
Published: 27 September 2016
Alchemy Jurnal Penelitian Kimia, Volume 10, pp 40-48; https://doi.org/10.20961/alchemy.v10i1.9

Abstract:
The preparation and characterization of bimetallic catalysts using impregnation method with a variation of concentration of precursor sequence Co and Mo metal obtained catalyst K 1 [Co (0.018 M) - Mo (0.037 M)/USY]. K 2 [Co (0.026 M) - Mo (0.055 M)/USY], K 3 [Co (0.035 M) - Mo (0.074 M)/USY], K 4 [Co (0.05 M) - Mo (0.11 M )/USY] and K 5 [Co (0.107 M) - Mo (0.22 M)/USY].Character of the catalyst in terms of crystallinity was analyzed by XRD. The result shows that there is no cristalinity damage of USY after impregnation but the amorphous cristalin structure was obtained. Amount of metal content was analyzed by XRF and the catalyst morphology by SEM-EDS. The result shows that the higher the concentration of Co and Mo so that find the higher content of metal in catalyst of the prepared catalyst increase. K 4 shows the best characteristic of catalysts prepared in this research. Analysis of K 4 is proving that Co and Mo are presented in catalyst
Dyah Choiriyah, Esfi Riandini, Arinta Wulandari
Published: 9 December 2015
Alchemy Jurnal Penelitian Kimia, Volume 11; https://doi.org/10.20961/alchemy.v11i1.100

Abstract:
The study of ceramic membrane fabrication from natural zeolite and its utilization for filtration of procion red MX8B and methylene blue has been investigated. The purposes of this study are to determine the effect of pressure on membrane permeability and selectivity and utilize natural zeolite as ceramic membranes procion red MX8B and methylene blue filtration. The membrane was prepared by metide press pellets and then calcined at 850 oC. The membranes were characterized by mechanical test, flux and rejection of dye. The compression test of the membrane found the values of 1369.178 psi in dry conditions to 1388.933 psi in wet conditions. The flux test found that the higher the pressure applied, the flux was increase. However, the high pressure also decreased the selectivity. Rejection test found that the rejection of methylene blue filtration up to 70 %. Meanwhile, procion red MX8B filtration has rejectivity less than 20 %.
Erin Ryantin Gunawan, Siska Ayu Wulandari, Emmy Yuanita, Dedy Suhendra
Published: 27 September 2016
Alchemy Jurnal Penelitian Kimia, Volume 10; https://doi.org/10.20961/alchemy.v10i2.528

Abstract:
Fossil fuel is commercial energy sources in many communities where their abundance progressively reduced and the resulting environmental pollution. Biodiesel is one alternative fuel made from vegetable which oils are suitable to replace the function of fossil fuels and environmentally friendly. Synthesis of biodiesel from cotton seeds oil was carried out by chemically ransesterification process. Composition of methyl esters in biodiesel thatwas analyzed by GC-MS are methyl palmitate (16.71%), methyl 8,11-octadecadienoic (46.45 %) and methyl linoleate (4.21 %).The highest amount of biodiesel conversion isat ratio of oil and methanol (1:1) with the catalyst 1% (weight of oil). The produced biodiesel was 93.7 %. Chemical properties of the produced biodiesel meets the standard SNI 04-7182-2006 i.e. saponification value of 120.167 mg KOH / g, acid value of 0.28 mg KOH / g and iod value 55.84g iod/100g of sample.
Dindha Ramah Mulia, Nestri Wulandari, Muhammad Widyo Wartono
Published: 27 September 2016
Alchemy Jurnal Penelitian Kimia, Volume 10; https://doi.org/10.20961/alchemy.v10i2.56

Abstract:
A xanthone, named ananixanthone (1) has been isolated and identified from the ethyl acetate extract of the root barks of Calophyllum soulattri. Structure of the compound was determined based on spectroscopic data, including UV, IR, NMR 1D, NMR 2D and by comparison with references.
Rais Nur Latifah, Roro Ernia, Edi Pramono
Published: 27 September 2016
Alchemy Jurnal Penelitian Kimia, Volume 10; https://doi.org/10.20961/alchemy.v10i1.13

Abstract:
Research of Pb ions adsorption with chicken feathers adsorbent has been conducted. This research aims to determine adsorption properties of activated chicken feathers and the chicken feathers that were not activatedby Na2S for Pb ions. The adsorption process was conducted by batch method with variation of the concentration, pH, and contact time. Pb content in solution is characterized by AAS spectroscopy (Atomic Absorption Spectroscopy). The results show that the contact time and pH condition for adsorption equilibrium are 60 min for activated chicken feathers and 90 min for chicken feathers which were not activated by Na2S at pH 8. Pb absorption by chicken feathers follows Freundlich isotherm and the reaction kinetics follow the Ho equation.
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