Judul: Elektrooksidasi Reduksi Tembaga(II) dan Perak(I) pada Elektrode Pasta Karbon Termodifikasi Kuersetin
Abstrak: Quercetin is one of flavonoids that can form complexes with metal ions to be used as a modifier of carbon paste electrodes. The initial step to determine the performance of quercetin modified carbon paste electrode is by looking for patterns of elektrooxidation reduction with cyclic voltammetry method. Voltammogram cyclic of ions Cu(II) and Ag(I) produces anodic and cathodic peaks that are quasireversible. The increase in the anodic and cathodic current intensity were 7.55% and 60.89%, respectively, for Cu (II), while those for Ag (I) were 41.52% and 194.46%, respectively. Voltammogram of mixture of Cu(II) and Ag(I) produced two pairs of anodic and cathodic peaks that can be used for analysing mixture of Cu(II) and Ag(I).
Keyword: Bogor Agricultural University (IPB), voltammetry, silver(I), copper(II), quercetin, electrode

Judul: Elektrode Pasta Karbon Termodifikasi Kuersetin untuk Analisis Ion Tembaga(II) secara Voltammetri
Abstrak: Quercetin is a flavonoid compound that can form stable complexes with various metal ions. Its use as a modifier for carbon paste electrode is expected to improve sensitivity in measurement by voltammetry. Quercetin-modified carbon paste electrode used for copper(II) ions analysis was evaluated in terms of the effect of some parameters such as quercetin composition, scan rate, pH, preconcentration time, preconcentration potential, and linearity of measurement. Copper-(II) ions analysis with cyclic voltammetry at potential range of -0.5–1.0 V resulted well-defined 2 pairs of reduction-oxidation peaks with the optimum conditions for reliable measurement were 0.1 M NaCl pH 6, and 5% quercetin. The cyclic voltammetry response was linear with the determination coefficient 0.995 in the concentration range of CuCl2 2.0–100 mM. Anodic stripping voltammogram resulted the optimum preconcentration potential of -600 mV and preconcentration time of 80 s. The anodic stripping voltammogram was linear with the determination coefficient 0.983 in the concentration range of CuCl2 0.2– 0.8 mM. This modified electrode increases the intensity of the current and can be developed for environmental samples measurement.
Keyword: anodic stripping voltammetry, copper(II), electrode, quercetin

Judul: Karakteristik Anatomi Skelet Kepala Buaya senyulong (Tomistoma schlegelii).
Abstrak: Buaya sepit atau senyulong (Tomistoma schlegelii) merupakan jenis buaya asli Indonesia yang berhabitat di sungai-sungai Sumatera, Kalimantan, dan juga pedalaman Sulawesi. Salah satu ciri khas buaya senyulong adalah bentuk moncong yang runcing dan sempit, namun hingga saat ini informasi mengenai struktur skelet kepala buaya senyulong sangat terbatas. Penelitian ini bertujuan untuk mempelajari karakteristik anatomi skelet kepala buaya senyulong yang dikatikan dengan fungsi dan perilakunya. Penelitian dilakukan secara eksploratif dengan melakukan pengamatan, pencatatan, dan pengambilan gambar dari skelet kepala buaya senyulong. Skelet kepala berukuran panjang 70 cm, lebar 29 cm, dan tingggi 17 cm dengan permukaan kasar pada os nasale, os frontale, os maxilla, os mandibula, os lacrimale, os jugale. Jumlah gigi pada buaya ini sebanyak 78 buah, terdiri dari 4 buah gigi premaxila, 16 buah gigi maxila, dan 19 buah gigi mandibula. Pada regio orbitalis ditemukan dua pasang fenestrae temporales yang berkembang baik. Fenestra supratemporale merupakan lubang oval yang membentang di sepanjang os parietale. Fenestra infratemporale berbentuk segitiga dan dibatasi oleh os squamosum, os postorbitale, os jugulare, dan os quadratum. Os mandibula hewan ini mempunyai symphysis mandibularis yang panjang yaitu garis yang melintang di corpus mandibulae. Secara fungsional ukuran symphysis mandibularis berkaitan dengan adaptasi hewan terhadap diet makan.
Keyword: kepala, moncong, Tomistoma schlegelii