Judul: Metode Cepat Penentuan Brazilin dalam Produk Jamu dan Kayu Secang menggunakan Spektrofotometri Derivatif Ultraviolet
Abstrak: Brazilin is an active compound in sappan wood with a lot of bioactivity and serves as fingerprint compound for sappan wood. Fast and efficient method must be used to measure brazilin contents in sappan wood and jamu product to control it’s quality. In this research, ultraviolet derivative spectrophotometry (UVDS) method was developed to determine the content of brazilin in sappan wood and jamu product. The optimum conditions of measurement and preparation for UVDS methods was determined beforehand. The optimum conditions for measurements obtained were scan speed at 200 nm / min, the second-order derivatives, the maximum wavelength of 231 nm (sappan wood) and 232 nm (jamu products), smoothing order of 4, and the number of points 11 (sappan wood) and 19 (jamu products). The optimum conditions of preparation with the parameter such as solvent, sonication time, and the volume of solvent, obtained for sappan wood were methanol, 5 min, and 5 mL, while for jamu product were ethanol, 30 minutes, and 30 mL respectively. The results of measurements of brazilin in sappan wood and jamu products by UVDS method were 5.4091 and -5.9585 mg/g. Those results were significantly different from those using high performance liquid chromatography, which were 2.2889 mg/g for sappan wood, and 0.7575 mg/g for jamu product. The developed UVDS method was less expensive and faster, but the accuracy of this method was still in doubt
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Judul: The Development of Brazilin Isolation Method from Sappan Wood (Caesalpinia sappan)
Abstrak: The objectives of this research was to develop efficient and effective the brazilin isolation method from sappan wood (Caesalpinia sappan) to obtain high yield and high purity. Brazilin is a compound with a lot of activities, but it is difficult to find this compound as standard. The development method was done by modifying the extraction method and optimizing the mobile and stationary phase in the separation process. Modification of the extraction was done by removing non-polar compounds with n-hexane. The yield of methanol fraction was 8.64 % (w/w) while the yield of n-hexane fraction was 0.93 %. The optimum mobile and stationary phase were chloroform: methanol (5:1) and silica gel for thin layer chromatography (TLC) and column chromatography. Methanol extract was column chromatographed, eluted with chloroform;methanol (5:1) to get the early fractions (Rf 0.89 in TLC condition). The fractions were further purified by preparative TLC. The results were analyzed by high performance liquid chromatography (HPLC) and characterized by UV-Vis and FTIR spectrometry. The yield of brazilin obtained 21.43 % (w/w) Rf value on TLC was 0.54 and the HPLC retention time was 15.695 minutes.
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Judul: Feeder kelinci ternak otomatis menggunkan prinsip aktuator solenoid
Abstrak: Feeder kelinci ternak otomatis merupakan prototipe yang diciptakan dengan pengaturan distribusi pakan berbentuk pellet pada konveyor sekrup termodifikasi dengan tambahan pintu akses teraktivasi oleh aktuator solenoid. Mikrokontroler Arduino Uno R3 pada prototipe ini digunakan untuk proses perhitungan jarak pintu akses, waktu tempuh pakan, dan kecepatan distribusi pakan. Prototipe ini bermanfaat untuk para pembudidaya/peternak kelinci sebagai inovasi teknologi dalam kegiatan pemeliharaan kelinci secara moderen. Pakan kelinci diatur melalui rotasi motor stepper pada penakar pakan sehingga dapat mengukur porsi pakan secara akurat. Penggunaan motor DC dilengkapi gearbox bertujuan mengendalikan konveyor sekrup agar berputar dengan konstan sehingga menghasilkan gaya dorong pada pakan yang akan didistribusikan. Hasil perhitungan kecepatan distribusi pakan menentukan waktu aktivasi aktuator solenoid yang akan membuka pintu akses pakan untuk keluar dari konveyor sekrup.
Keyword: Aktuator solenoid, feeder, penakar pakan, konveyor sekrup