Judul: Pengaruh Pelarut pada Rendemen Sintesis Zink bis(dibutil ditiofosfat)
Abstrak: Aditif pelumas yang digunakan di Indonesia masih diimpor. Salah satu aditif pelumas multifungsi adalah zink dialkilditiofosfat (ZDTP) yang berfungsi sebagai antioksidan, antiaus, antikorosi, dan penghambat lecet. Sintesis ZDTP telah banyak dilakukan dan beberapa metode telah dikembangkan. Metode yang digunakan pada penelitian ini relatif mudah dan sederhana, dengan pereaksi yang relatif mudah diperoleh. Digunakan beragam pelarut organik dalam sintesis tersebut, yaitu n-heptana, dietil eter, dan kloroform. Rendemen Zink bis(dibutil ditiofosfat) pada ketiga pelarut tidak berbeda nyata, untuk pelarut n-heptana, dietil eter dan kloroform berturut-turut 97%, 92%, dan 98% dengan waktu reaksi masing-masing 12 jam di kedua tahap. Pencirian gugus fungsi Zink bis(dibutil ditiofosfat) dengan spektrofotometer inframerah transformasi Fourier menunjukkan pita serapan yang hampir sama untuk ketiga pelarut. Hasil analisis kromatografi cair kinerja tinggi menunjukkan bahwa waktu retensi Zink bis(dibutil ditiofosfat) hasil sintesis dengan pelarut n-heptana, dietil eter, dan kloroform mirip dengan waktu retensi ZDTP autentik komersial.
Keyword: Bogor Agricultural University, Institut Pertanian Bogor, IPB, Diethyl ether, Chloroform, N-heptane, ZDTP, Zink bis(dibutyl dithiophosphate)

Judul: Pengaruh Pelarut pada Rendemen Sintesis Zink bis(dibutil ditiofosfat)
Abstrak: Lubricant additives used in Indonesia are still imported. Zink dialkyldithiophosphate (ZDTP) is a multifunctional oil additives, works as an antioxidant, antiwear, anticorrosion, and antiscuff. Synthesis of ZDTP has been widely performed and several methods have been developed. The method used in this study was relatively easy and simple, and the reagents were relatively easy to obtain. Various organic solvents were used in the synthesis, namely n-heptane, diethyl ether, and chloroform. Zink bis(dibutyl dithiophosphate) yield in all three solvents did not differ markedly, 97%, 92%, and 98%, respectively, with reaction time of 12 hours each in both steps. Functional group characterization of Zink bis(dibutyl dithiophosphate) using Fourier transform infrared spectrophotometer showed similar absorption bands for all three solvents. The high performance liquid of chromatography analysis results showed that the retention time of Zink bis(dibutyl dithiophosphate) synthesized using n-heptane, diethyl ether, and chloroform were similar to that of commercial authentic ZDTP.
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Judul: Mitochondrial DNA Gene Organization and Phylogenetic Relationship of Naja siamensis
Abstrak: Naja siamensis is one of Asiatic cobra in the Family of Elapidae, known as a cryptic snake. It has many morphological variations that lead to misidentification. Misidentification can cause the wrong concept in developing antivenom types due to high snakebite cases occur in Thailand. Thus, an accurate species identification using a molecular approach is crucially required. Mitochondrial DNA has been used widely in snake molecular studies. These studies were aimed to determine the arrangement of the N. siamensis partial mitochondrial genes using reptile-oriented primers and to reveal the phylogenetic relationship among other species of Asian cobra. DNA extraction was carried out based on the standard DNA salting-out protocol and was conducted by bioinformatics analysis using BLASTn and MEGA 6 software. Gene annotation was performed against N. kaouthia complete genome. A total of 3121 bp of N. siamensis mtDNA genes were sequenced consisting of partial of six regions: 16S rRNA, ND1, tRNA-Ile, CRII region, tRNA-Leu, tRNA-Gln, and COI genes. The mtDNA gene organization of N. siamensis was predicted to has a similar pattern with the common Elapidae mtDNA gene organization. This study showed that there is a monophyletic form in Naja genus and N. kaouthia is the closest species with N. siamensis based on partial 16S rRNA and ND1 gene.
Keyword: 16S rRNA, Elapidae, ND1, phylogenetic relationship