161 research outputs found
Kajian penentuan sebatian organoarsenik menggunakan pelbagai kaedah voltammetri dengan elektrod titisan raksa tergantung
No full textVarious voltammetric methods including cyclic voltammetry (CV), differential pulse cathodic stripping voltammmetry (DPCSV), differential pulse anodic stripping voltammmetry (DPASV) and differential pulse voltammmetry (DPV) were used for the determination of six organoarsenic compounds, namely (phenylarsonic acid (PAA), para-arsanilic acid (p-ASA), ortho-arsanilic acid (o-ASA), 4-nitrophenylarsonic acid (4-NPAA, nitarsone), 3-nitro-4-hydroxy phenylarsonic acid (3-NHPAA, roxarsone) and para-ureidophenylarsonic acid (p-UPAA, carbarsone). Hanging mercury drop electrode (HMDE) was used as the working electrode. Dilute 0.1 M HCl and Britton Robinson (BR) buffer 0.04 M at pH = 3.0 were used as the supporting electrolyte solutions. The experimental parameters optimized are the effects of scan rate, pH, initial potential, accumulation potential, accumulation time and interferences. DPCSV method was used for indirect determination of p-ASA and o-ASA based on diazotization and coupling reaction. Cyclic voltammogram cathodic scan showed an irreversible peak of arsonic acid group for PAA, p-ASA, o-ASA and p-UPAA. Whereas two irreversible peaks of nitro and acid arsonic groups were observed for 4-NPAA and 3-NHPAA. Anodic scan for all of the compounds showed two oxidation peaks for phenylarsine and phenylarsenous oxide groups respectively. Two couples of redoxs peaks for phenylarsine and phenylarsenous oxide groups were identified after two-cycles of cyclic voltammogram. By utilizing a pre-scan process, the DPCSV method showed two sharp peaks of phenylarsenous oxide and phenylarsine groups respectively for PAA, p-ASA, o-ASA, p-UPAA. On the other hand, one broad and low reduction peak was observed for acid arsonic group. DPCSV method also showed reduction peak of nitro group for organoarsenic compounds that certain nitro groups namely the 4-NPAA and 3-NHPAA. DPV cathodic scan result for PAA, p-ASA, o-ASA, p-UPAA showed one reduction peak of acid arsonic group, while two reduction peaks of nitro and acid arsonic group for 4-NPAA. The DPASV analysis for all the compounds, showed two oxidation peaks of phenyl arsine and phenylarsenous oxide. The method was validated by using reproducibility, limit of detection and recovery study. The limit of detection for all organoarsenic compounds were found to be in the range of 1.48 to 4.56 x 10-8 M (DPCSV), 1.35 to 4.27 x 10-8 M (DPASV) and 2.3 x 10-8 M (DPV cathodic scan). The RSD were found to be in range of 1.35 % - 4.64 %, while the percentage of recovery studies in the range of 80 % - 98.67 %. DPCSV method was succesfull to differentiate p-ASA and o-ASA via diazotization and coupling reaction at various conditions
ANALISA MORFOLOGI CARBON DOTS (C-Dots) DARI AIR TEBU
No full textCarbon dots (C-dots) measuring less than 10 nm are currently the center of attention in nanocarbon materials. C-dots have unique physicochemical and photochemical properties that make C-dots a promising platform for imaging, environmental, catalytic, biological and energy-related applications. Sugarcane (Saccharum officinarum) is an annual plantation crop that is used as raw material for making sugar. The main content of sugarcane juice is sucrose (70-88%). The sugarcane juice content and low price make sugarcane juice suitable for use as a basic material for making carbon dots (C-dots). The process of making C-dots from sugarcane juice is done by adding urea as a passivation agent using the microwave method with a power of 110 watts. Sugarcane juice and urea (10:1) were dissolved with distilled water, stirred and heated at a temperature of 70 C for 15 minutes. The solution was then put in the microwave to dry (20 minutes). The gel formed was then dissolved with distilled water, centrifuged and then dialyzed for 24 hours. Morphological analysis of C-dots was performed by TEM analysis, showing that C-dots had an average diameter of 6.2 nm
Effect of Nanocrystal Cellulose Isolated from Empty Fruit Bunches (Elaeis Guineensis Jack) Addition on Morphological and Mechanical Properties of Natural Rubber Latex Product.
No full textThe research about the effect of the addition of nano crystal cellulose (NCC) isolated from empty palm bunches (EPB) on the morphological and mechanical properties of natural rubber latex products was successfully conducted. This research was carried out in three steps: i.e isolation of α-cellulose from EPB, followed by isolation NCCs from α-cellulose using H2SO4 48.84% at 45ºC for 25 minutes, and manufacture of latex compound with varying filler NCC were 0, 0.6, 1.2, 1.8, 2.4, and 3.0. Manufacturing of natural rubber product was made with pour the NRL followed by vulcanized at 120ºC for 30 minutes. The sheet of NRL product was produced later characterized its mechanical properties through tensile test and surface morphology analysis by SEM. The optimum value of the tensile test result of the NRL product sheet was at the addition of 1,2 phr of NCC with values of tensile test, elongation at break, and Young’s modulus was 3.771 MPa, 877%, and 0.430 Mpa respectively. In addition, surface morphology analysis showed that the NCC was spread evenly
Penentuan Kadar Fosfat dalam Limbah Cair Industri Detergen dan Kadar Amonia dalam Limbah Cair pelayanan Kesehatan dengan Metode Spektrofotometri UV-Visible
No full textDetermination of Phosphate levels in detergent industrial liquid was wastewater and Ammonia levels in health service liquid was wastewater with the UV-Visible spectrophotometric method had been carried out at the UPT Laboratorium Lingkungan Dinas Lingkungan Hidup Provinsi Sumatera Utara. Determination of Phosphate levels, carried out by the addition of phenolphthalein indicator in to the sample, followed by the addition of a mixed solution consisting of sulfuric acid, potassium antimonyl tartrate, ammonium molybdate, ascorbic acid, then homogenized. The homogeneous solution was analyzed using a UV-Visible spectrophotometer at a wavelength of 880 nm. Determination of ammonia levels, carried out by the addition of phenol solution, sodium nitroprusid solution, and oxidizing solution into the sample and homogenized, then closed and left for 1 hour then analyzed using a UV-Visible spectrophotometer at a wavelength of 640 nm. Based on the results of the calculations carried out, Phosphate levels were obtained for each sample with codes A, B, and C, obtained at 0.7368 mg/L; 0.6831 mg/L; and 0.7737 mg/L. Ammonia levels for each sample with codes D, E, and F were obtained at 0.3713 mg/L; 0.6716 mg/L; and 1.5329 mg/L. In accordance with the Regulation of the Minister of Environment of the Republic of Indonesia No. 5 of 2014 concerning Wastewater Quality Standards, that the maximum level for Phosphate is 2 mg/L and the maximum level for Ammonia is 10 mg/L. Based on the analysis data that has been obtained, it shows that the Phosphate levels in industrial detergent liquid was wastewater and Ammonia levels in health service liquid was wastewater meet the requirements for wastewater quality standards.44 HalamanKertas Karya Diplom
Selektivitas dan Sensitivitas Nitrogen-Doped Carbon Dots Berbasis D-Glukosa Monohidrat yang Disintesis dengan Metode Hidrotermal untuk Deteksi Ciprofloxacin
No full textPeningkatan penggunaan ciprofloxacin (CIP), antibiotik golongan kuinolon, di Indonesia dan global menimbulkan kekhawatiran terhadap resistensi antimikroba dan kontaminasi lingkungan akibat residu obat yang tidak sepenuhnya terdegradasi dalam tubuh. Oleh karena itu, pengembangan metode deteksi yang sensitif dan selektif menjadi sangat penting. Penelitian ini bertujuan untuk mensintesis dan mengkarakterisasi carbon dots (CDs) dan nitrogen-doped carbon dots (N-CDs) berbasis d-glukosa monohidrat dengan metode hidrotermal, serta aplikasinya sebagai detektor terhadap ciprofloxacin. Karakterisasi CDs dan N-CDs dilakukan menggunakan spektroskopi UV-Vis, FTIR, Spektrofotometer fluoresensi, Raman, HR-TEM, dan XPS. Uji sensitivitas dilakukan dengan variasi konsentrasi CIP (0,50–3,50 μM), sementara uji selektivitas menggunakan antibiotik lain sebagai pembanding. Hasil penelitian menunjukkan bahwa CDs dan N-CDs dari uji HR-TEM memiliki ukuran partikel masing sekitar 2,72 nm dan 5,45 nm. Analisis UV Vis menunjukkan CDs dan N-CDs puncak serapan pada 273 nm dan 397 nm. Spektrum fluoresensi menunjukkan bahwa CDs dan N-CDs memiliki intensitas fluoresensi berada pada panjang gelombang 435 nm dan 445 nm serta menunjukkan emisi hijau kekuningan (CDs) dan biru (N-CDs). Analisis FTIR menunjukkan adanya gugus –NH, C–N, dan C=O yang menandakan bahwa nitrogen berhasil di doping pada permukan carbon dots. Analisis XPS dari CDs dan N-CDs menunjukkan adanya dua komponen unsur pada CDs yakni C1s (C–C 284,8 eV; C–O 286 eV) dan O1s (C–O 532,6 eV), sedangkan pada N-CDs memiliki kesamaan dengan CDs, tetapi ada sedikit perbedaan yaitu pada N1s (N–H 399,6 eV) dan O1s (O=C–N 531,1 eV dan O=C–O 532,1 eV). N-CDs digunakan sebagai detektor CIP dengan uji sensitivitas dan selektivitas. Nilai LOD yang dihasilkan sebesar 0,24 µM dengan rentang deteksi 0,50–3,50 µM dan detektor N-CDs sangat selektif terhadap analit.Lembaga Pengelola Dana Pendidikan139 PagesTesis Magiste
Pengaruh Suhu dan Konsentrasi Nacl Terhadap Tegangan Permukaan Larutan Pencuci Tangan Skripsi
No full textThe investigation of The effect of Temperature and concentration of NaCl to Surface
Tension of Hand Wash Liquid was carried out. The investigation was done by
measuring the surface tension of hand wash liquid with various temperature (300
C,
400 C, 500 C) and various concentration of NaCl (10%, 20%, 30%). The surface
tension of hand wash liquid was measured with using method of capillary rise tube.
From data and calculation result using variant analysis, it was showed that there was
the effect of temperature and concentration of NaCl to surface tension of hand wash
liquid. If the temperature and concentration of NaCl increase so surface tension of
hand wash liquid will be decrease. But if temperature and concentration of NaCl
decrease so surface tension of hand wash liquid will be increase.62 HalamanSkripsi Sarjan
Degradation of Natural Rubber as Asphalt Mixes Modifier using UV-Ozone Light
No full textThe elastic properties of natural rubber are indispensable in improving the physical properties of asphalt mixtures. However, the long natural rubber molecule chains make it difficult to modify with other polymeric materials, so it needs to be degraded. In this study, the authors succeeded in degrading natural rubber using a combination of UV light and ozone with the addition of an H2O2 initiator; from the FTIR data, it appears that there are peaks indicating vibrations of the C=O and –OH groups indicating that natural rubber chain termination has occurred. The addition of natural rubber to asphalt was carried out with several variations, namely 8; 10; 12; 14; 16 % (to asphalt content), from the results of the softening point and ductility test of the asphalt mixture explained that the addition of 12 % natural rubber was the most optimum mixture. This result explains that efforts to degrade natural rubber using the UV - ozone combination method can increase the optimum insertion of natural rubber into asphalt mixtures by up to 100 % from previous studies
Impact of the Concentration Ethylenediamine on Optical Properties of Carbon Dots from Jengkol Peel (Archinendron pauciflorum)
No full textCarbon dots (CDs) are a new member of fluorescent nano carbons that have attracted attention because of their potential applications derived from their optical, chemical, and electrical properties. CDs from jengkol peel via the solvothermal method at 200 oC for 7 h with the addition of ethylenediamine (EDA) as a heteroatom dopant have been successfully carried out. This study aims to determine the effect of concentration EDA on the optical properties of CDs for the possible reason. The results revealed that the CDs solution has fluorescence properties; that bluish-green glow can be observed under ultraviolet radiation (365 nm). The UV - Vis absorption peaks did not depend on the CDs concentration, but the absorbance intensity decreased with increasing EDA concentration. The best fluorescence properties were possessed by 10 % EDA in CDs which produced λex/λem of 370 nm / 518 nm, respectively, with a quantum yield of 42 %. The FTIR spectra of all samples showed that the CDs surface had functional groups such as carboxylic acids, hydroxyl, and amines. The obtained CDs have the potential to be used as heavy metal ion detectors, bioimaging, and antibacterial agents
Identifikasi Klorpirifos pada Komoditi Kakao dengan Metode Kromatografi Gas
No full textThe determination of chlorpyrifos pesticide residues in cocoa has been done that
comes from Karo and Labuhan Batu district performed in Balai Besar Proteksi
and Perbenihan Tanaman Perkebunan( BBPPTP ) Medan. Analysis has been done
by sample extraction using acetone and dichloromethane. Extract is evaporated
until almost dry and the residue is dissolved in isooctane and toluene and
determined by gas chromatography using a flame photometric detector ( FPD)
with filter P (526 nm). The Results showed that the cocoa from Karo and
Labuhan Batu district does not found the content of chlorpyrifos.42 HalamanKertas Karya Diplom
Sintesis dan Karakterisasi Selulosa Bakteri dari Ekstrak kulit Nanas dengan Penambahan Air Kelapa
No full textSynthesis of bacterial cellulose from pineapple peel extract with the addition of coconut water has been carried out. Pineapple skin extract and coconut water with at ratio of 1:0, 1:1, and 2:1, added 25 grams of sugar, 2 grams of Ammonium sulfate (ZA), then heated while stirring until boiling. Then the medium was cooled and glacial CH3COOH was added until it reached pH=4 and 10% Acetobacteri xylinum bacterial starter then fermented for 10 days. Bacterial cellulose obtained was in the form of a floating layer on the surface of the media, then purified with 2,5% NaOH for 24 hours, bleached with 2,5% NaOCl for 24 hours, and washed with aquadest until the pH reached neutral. The yield value of the bacterial cellulose obtained was determined and characterized by FTIR, XRD and SEM. Bacterial cellulose with at ratio of 1:1 gave the best results with a yield value of 0,71%. The FTIR spectrum shows the formation of pure bacterial cellulose which is characterized by the presence of functional groups O-H, C-H, C=O, C=C, C-O-C at each wave number 3286.69, 2923.83, 1245.02, 1554.22 and 951, 09 cm-1. The surface morphology of bacterial cellulose shows the formation of fine threads (microfibrils) that are tightly intertwined at random, overlapping each other and the shape of cellulose fibers is uneven. The XRD diffractogram shows a degree of crystallinity of 87,67%.59 HalamanSkripsi Sarjan
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