Judul: Prosedur Pengukuran Berbasis Fluorimetri Untuk Mengukur Konsentrasi Kurkumin Di Dalam Obat-Obat Herbal Komersial
Abstrak: Masyarakat Indonesia telah secara turun-temurun menggunakan obat herbal tradisional, yang dikenal sebagai jamu, untuk mengobati dan melindungi tubuh dari penyakit. Kebiasaan penggunaan jamu ini memberi implikasi akan pentingnya kebutuhan untuk meningkatkan dan mengembangkan beberapa standar kualitas jamu. Atas dasar ini, sistem standardisasi yang baik sangat diperlukan untuk mendapatkan kualitas jamu yang memenuhi standar kelayakan, efektif, dan berkualitas tinggi. Kunyit (Curcuma longa) dan temulawak (Curcuma Zanthorrhiza) adalah tanaman obat yang banyak dimanfaatkan sebagai bahan utama jamu oleh orang Indonesia. Kedua bahan tersebut mengandung kurkumin yang merupakan komponen aktif utama pada rhizoma (akar rimpang). Berbagai jenis metode telah dikembangkan dalam penentuan kadar kurkumin di dalam tumbuhan obat, seperti (1) teknik spektrofotometri UV-Vis, (2) teknik kromatografi lapisan tipis (Thin-Layer Chromatography), dan (3) teknik High Performance Liquid Chromatography (HPLC). Meskipun metode-metode tersebut tersedia dan dapat digunakan, suatu teknik analisis kurkumin yang penerapannya sederhana, memberikan hasil yang cepat, peka, tepat, dan berbiaya murah masih menjadi masalah utama di Indonesia. Dalam studi ini kami mengajukan dan menggunakan sebuah metode penentuan kadar kurkumin alternatif berbasis fluorimetri. Metode ini dapat diterapkan untuk analisis obat herbal yang mengandung komponen zat yang dapat berfluoresensi, seperti kurkumin, yang menunjukkan gejala fluoresensi kuat di dalam pelarut organik. Metode fluorimetri ini memiliki kadar sensitivitas dan selektivitas yang lebih tinggi dibandingkan dengan teknik spektrofotometri dan metode ini juga lebih sederhana dan murah dibandingkan dengan teknik analisis kromatografi. Tiga tahap utama dalam studi ini meliputi: persiapan kurva standar kalibrasi kurkumin, penentuan konsentrasi kurkumin di dalam sampel, dan perbandingan terhadap hasil yang diperoleh menggunakan teknik HPLC. Pengukuran fluoresensi dilakukan pada fluorometer FLUOstar Omega yang menggunakan spektrometer UV-Vis. Level fluoresensi yang muncul berbanding lurus dengan intensitas cahaya yang datang dan konsentrasi dari bahan fluoresen yang diamati. Kurva kalibrasi standar yang dihasilkan menunjukkan hubungan yang linear dan positif antara konsentrasi dan intensitas fluoresensi. Tingginya nilai koefisien determinasi juga menunjukkan bahwa hubungan tersebut sangat jelas. Evaluasi kinerja dari metode fluorimetri ini dilakukan dengan membandingkan konsentrasi- konsentrasi yang diperoleh dari pembacaan hasil fluorometer terhadap hasil yang diperoleh dari HPLC.
Keyword: fluoresensi, kurkumin, kunyit, temulawak, fluorometer, analisa HPLC

Judul: Penentuan Kadar Kurkuminoid dalam Kunyit dengan Spektrofotometri Derivatif
Abstrak: Indonesia as one of agricultural countries has various kinds of plant than can be used for pharmaceutical product, including turmeric that contains curcuminoid compound. Curcuminoid has efficacy as an antihepatoxic, anticholesterol, tumor and cancer inhibiting compound. In recent years, research has been developing a simple, fast, and low-cost analysis method from spectroscopy and chemometric combination, i.e. ; derivative spectrophotometry. In this research, turmeric extraction was conducted using sonication method, and its curcuminoid content was determined using spectrophotometry method. Analysis with UV-vis spectrophotometry and high performance liquid chromatography (HPLC) were also conducted as reference methods. Curcuminoid in turmeric using derivative spectrophotometry was 14.33 mg/g whereas with UV-vis spectrophotometry and HPLC were 14.18 and 45.40 mg/g, respectively. Based on statistical analysis for these results, derivative spectrophotometry can be applied for analyzing curcuminoid content with good accuracy and precision. This developed method was cheaper, faster, and easier than the conventional method. In addition, matrices influence in samples can be reduced compared with that using conventional spectrophotometry.
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Judul: Thermal Characteristics and Dynamics of Tropical Cyclone over Western North Pacific Ocean: A Case Study of Typhoon Songda (Chedeng) 2011
Abstrak: The frequent occasion of Tropical Cyclone (TC) over Western North Pacific (WNP) Ocean lies from 10˚N to 26˚N and 121˚E to 170˚E. Sources of TC development come from warm ocean temperature where latent heat is released during condensation processes and subsequently concentrated in the boundary layer. Relative humidity at 850-700 hPa is responsible to produce the most intense storm. Meanwhile, weak vertical wind shear between 850-200 hPa is one of the dynamical factors that lead to the development of TC. Pressure level of 850-200 hPa is chosen to minimize the thermodynamic effect in the lower troposphere. Typhoon Songda (Chedeng in the Philippines) or TSC lasted from May 18th to 30th, 2011 and strengthened into powerful Super Typhoon stage between May 24th and 27th. Long curving track and the exhibition of all sequences of TC life cycle, TSC is then considered as an ideal case of TC. The objective of the study with case of TSC is to investigate the role of thermal characteristics and dynamics on TC intensity. The research is carried out by using Advanced Research of Weather Research and Forecasting model (WRF ARW model) version 3.3. Two domains are employed in the model. The first domain situate from 02˚N to 40˚N and 118˚E to 149˚E and cover spatial resolution () of 33.1 km. The second domain situate from 09˚N to 27˚N and 119˚E to 132˚E with of 11 km. Timestep of the model () is 120 seconds. The model is supported by the following physical parameterization, i.e., Yonsei University Scheme (YSU) in the boundary layer, Kain-Fritsch scheme (KF) in the cumulus, and WRF Single-Moment 3-class scheme in the microphysics. Initial meteorological condition prior to the formation of the cyclone is generated using WRF ARW standard-release model. Sensitivity of the model output is obtained from a selected single-parameter change scenarios, namely, 10 % to 20 % decrease and increase of wind shear initial data at 850-200 hPa, and by 10 % to 20 % decrease of relative humidity initial data at 850-700 hPa. The result showed that the negative correlations between wind shear and intensity are found in wind shear scenarios. Wind shears of 10 ms-1 which lead to strengthening of the wind intensity in the early period of Typhoon development are found in wind shear scenarios. The effect of wind shear changes on wind intensity is statistically significant in the 20 % wind shear scenarios. During mature stage, weak wind intensity occurred when wind shear increase as given in the WRF standard-release and the 20 % decreasing scenario. Different situation is found in the 20 % increasing scenario where wind shear tend to weak and lead to strong wind intensity at this stage. Meanwhile, the reduction of moisture supply at 850-700 hPa resulting from 20 % decreasing relative humidity play a major role in the weakening of wind intensity and reduces mechanical energy of the cycle process as much as 300 J kg-1.
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