Judul: Pembuatan dan pencirian elektrode selektif ion Lu3+ (Lutetium) dengan Ionofor 4- odekanadioilbis-(1-fenil-3-metil-5-pirazolon)
Abstrak: The ion selective electrode (ISE) performance is affected by the type of ionophore used. This research developed an Lu3+ ISE with dodecanedioylbis-(1- phenyl-3-methyl-5-pirazolone) (H2DdBP) as ionophore which has been proved selective in Lu3+ liquid-liquid extraction. The best composition of ISE obtained from this research was 33% PVC, 57% acetophenone, 5% H2DdBP, and 5% oleic acid. Linear measurement was obtained with Nernst factor of 16.57 mV/decade at 10-3−10-7 M concentration range in very acidic situation and response time was 15 to 250 seconds. ISE still could be used at pH 4 and 7, with 5% Nernst factor decrease after 30 days usage. Other ions such as Cu2+, Cd2+, Pb2+, Ni2+, Ca2+, and La3+ did not affect the measurement of ISE.
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Judul: Sintesis dan Pencirian Senyawa 4-Dodekanadioilbis(1-fenil-3-metil-5-pirazolon) sebagai Ionofor untuk Penentuan Ion Lu3+ dengan Teknik Elektrode Selektif Ion
Abstrak: Ion selective electrode (ISE) as an alternative potentiometric method is used widely in determining Lu3+. The success of this method depends on the ionophor used on the ISE. The compound of 4-dodecanedioylbis(1-phenyl-3-methyl-5-pyrazolone) or H2DdBP as pyrazolone derivatives will be used as ionophor on ISE-Lu3+. H2DdBP had been successfully synthesized by Jensen’s method. This method involved reaction of 1-phenyl-3-methyl-5-pyrazolone and dodecanedioyl chloride in basic condition. A compound was produced as a solid substance and was purified by recrystallization using chloroform-ethanol. High performance liquid chromatogram showed that the compound was pure. The compound was in keto form with melting point range of 150-152ºC. Infrared spectra showed vibration peaks (cm-1) were 3451 (br, OH), 1624 (s, C=O), 1589 (s, phenyl C=C), 1558 (s, pyrazolone ring). Chemical shifts (Hz) for 1H-NMR were 7.81–7.84, 7.43–7.46, 7.26–7.290 (m, 10H, Ph); 2.72–2.75 (t, 4H, (CH2)2); 2.47 (s, 6H, CH3); 1.71–1.76 (m, 4H, (CH2)2); 1.32 (m, 12H, (CH2)6). All of these properties showed the characteristics of H2DdBP. Nernst factor of ISE-Lu3+ for two repetitions were 10.40 mV/decade and 8.60 mV/decade which showed that ISE-Lu3+ had good response in determining Lu3+.
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Judul: Perubahan Penutupan Lahan Dan Faktor Penyebabnya Di Cagar Alam Gunung Papandayan, Provinsi Jawa Barat
Abstrak: Gunung Papandayan telah ditetapkan sebagai Taman Wisata Alam (TWA) yang semula bagian dari Cagar Alam (CA). Gunung ini telah meletus tahun 2002, yang mengakibatkan perubahan struktur vegetasi. Selain ini dinamika perubahan penutupan lahan juga sangat dipengaruhi aktivitas masyarakat di sekitar kawasan. Teknologi penginderaan jauh dan Sistim Informasi Geografi (SIG) dapat digunakan untuk pemantauan dan identifikasi perubahan secara reguler. Penelitian ini bertujuan untuk mengetahui perubahan penutupan lahan dan faktor penyebabnya pada periode tahun 1990, 2002 dan 2013. Hasil analisis menunjukkan bahwa jenis tutupan lahan yang mengalami perubahan tertinggi pada tahun 1990–2002 adalah hutan pegunungan menjadi semak belukar seluas 1019.29 ha. Adapun perubahan tutupan lahan terbesar yang terjadi pada tahun 2002-2013, yaitu semak belukar menjadi hutan pegunungan seluas 793.07 ha. Fakta tersebut mengindikasikan bahwa kerusakan yang pernah terjadi pada tahun 2002, sebagian telah bersuksesi menjadi hutan kembali.
Keyword: Cagar alam Gunung Papandayan, perambahan hutan, perubahan penutupan lahan