Judul: Metode Penambahan Standar Titik-H untuk Penentuan Simultan Natrium Benzoat dan Kalium Sorbat
Abstrak: H-point standard addition method (HPSAM) can be used as a method of choice for the development of simultaneous determination of sodium benzoate and potassium sorbate concentrations because of its precision, accuracy, selectivity, and rapidity, in addition to its simplicity. HPSAM is based on twowavelength spectrophotometry and the standard addition method. Analyte concentrations to be determined were measured simultaneously using ultravioletvisible spectrophotometry at wavelength pairs selected; the standard calibration curve of interference is needed to calculate the concentration of interference. The data obtained were processed using a mathematical calculation. Potassium sorbate was selected as the analyte and sodium benzoate was chosen as interference because it showed better accuracy. Simultaneous determination of the concentration of sodium benzoate and potassium sorbate with HPSAM produced selected wavelength pairs at 212.2 and 233.4 nm. Sodium benzoate and potassium sorbate in some synthetic mixtures were determined simultaneously in the range of 4 and 1-1.5 mg/L, respectively, with good precision and accuracy.
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Judul: Metode Penambahan Standar Titik-H untuk Penentuan Simultan Natrium Benzoat dan Kalium Sorbat
Abstrak: H-point standard addition method (HPSAM) can be used as a method of choice for the development of simultaneous determination of sodium benzoate and potassium sorbate concentrations because of its precision, accuracy, selectivity, and rapidity, in addition to its simplicity. HPSAM is based on twowavelength spectrophotometry and the standard addition method. Analyte concentrations to be determined were measured simultaneously using ultravioletvisible spectrophotometry at wavelength pairs selected; the standard calibration curve of interference is needed to calculate the concentration of interference. The data obtained were processed using a mathematical calculation. Potassium sorbate was selected as the analyte and sodium benzoate was chosen as interference because it showed better accuracy. Simultaneous determination of the concentration of sodium benzoate and potassium sorbate with HPSAM produced selected wavelength pairs at 212.2 and 233.4 nm. Sodium benzoate and potassium sorbate in some synthetic mixtures were determined simultaneously in the range of 4 and 1-1.5 mg/L, respectively, with good precision and accuracy.
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Judul: Populasi Dan Habitat Lutung Jawa (Trachypithecus Auratus) Di Cagar Alam Dungus Iwul Kabupaten Bogor
Abstrak: Cagar Alam Dungus Iwul (CADI) dengan luasan ± 9 ha merupakan salah satu habitat alami Lutung Jawa (Trachypithecus auratus). Menurut Daftar Merah IUCN status konservasi lutung jawa adalah vulnerable dan termasuk dalam daftar Appendix II CITES. Keberadaan lutung jawa di CADI sudah ada sejak tahun 1931. Hasil penelitian yang dilakukan ditemukan dua kelompok lutung jawa yaitu kelompok 1 terdiri atas 24 individu dan kelompok 2 terdiri atas 2 individu. Sex ratio individu dewasa pada kelompok 1 (1:2.67) dan pada kelompok 2 (1:1). Aktivitas harian yang paling sering dilakukan adalah makan 41%. Wilayah jelajah seluas ± 6 ha dengan jumlah sebanyak 26 individu lutung jawa.Proporsi pakan lutung jawa didominansi oleh daun sebesar 76%. Tumbuhan iwul (Orania sylvicola) merupakan tumbuhan yang paling dominan. Pohon tidur lutung jawa paling banyak menggunakan pohon pohon kihujan(Engelhardtia spicata Lesh.), asem keranji (Dialum indum L) dan kibangkong (Endiandra rubescens). Aktivitas istirahat, makan dan aktivitas sosial lutung jawa banyak dilakukan pada strata A dan B, dan aktivitas berpindah banyak dilakukan pada strata C.
Keyword: habitat, lutung jawa, populasi