ABSTRAKSintesis C-sinamal kaliks [4]resorsinarena (CSKR) dari minyak kayumanis dan penggunanannya untuk ekstraksi fasa padat logam berat Pb(II) dan Hg(II) telah dilakukan. CSKR diperoleh sebanyak 75% sebagai produk reaksi resorsinol dan sinamaldehida pada 77 o C selama 24 jam. Isolasi sinamaldehida dari minyak kayumanis melalui metode bisulfit menghasilkan sinamaldehida sebanyak 79% dengan kemurnian 99,5%. Ekstraksi fasa padat Pb(II) dan Hg(II) oleh CSKR dilakukan dalam sistem batch pada berbagai pH, waktu interaksi, dan konsentrasi logam. Ekstraksi fasa padat Pb(II) berlangsung optimum pada pH 4, waktu interaksi 180 menit, dan konsentrasi awal 6,6 mg/L, mengikuti model kinetika pseudo orde dua, mengikuti model isoterm Langmuir, serta memberikan kapasitas ekstraksi sebesar 1,986 mol/g atau 37,2%. Sementara itu, ekstraksi fasa padat Hg(II) berlangsung optimum pada pH 5, waktu interaksi 180 menit, dan konsentrasi awal 0,36 mg/L, mengikuti model kinetika pseudo orde dua, mengikuti model isoterm Freundlich, serta memberikan kapasitas ekstraksi sebesar 0,71 mol/g atau 79,1%. Kata kunci : Ekstraksi Fasa Padat, Kaliks[4]resorsinarena, Minyak Kayumanis, Hg(II), Pb(II) PENDAHULUANPelepasan kation logam berat ke dalam lingkungan perairan telah menjadi permasalahan yang makin meningkat dalam beberapa dekade terakhir. Polutan yang telah menjadi sumber permasalahan utama adalah keberadaan timbal, kromium, merkuri, uranium, selenium, seng, arsen, kadmium, emas, perak, tembaga, nikel, dan lain sebagainya. Polutan tersebut merupakan polutan yang bersifat karsinogenik dan mutagenik. Bahan-bahan ini dapat berasal dari pekerjaan pertambangan, pemurnian bijih, abu layang dari tungku pembakaran, pemrosesan bahan-bahan radioaktif, pelapisan logam, atau pabrik alat-alat listrik, cat, alloy, baterai, pestisida atau pupuk.Prosedur yang umum digunakan untuk menghilangkan kation logam dari perairan adalah presipitasi, koagulasi, pertukaran ion, osmosis balik, dan ekstraksi
Vetiver oil (Vetiveria zizanoides) has been used as perfume materials, cosmetics, fragrance soaps, anti-inflammation, repellent, and insecticidal agents. Organic vetiver oil has higher economical value than non-organic vetiver oil and it has been regarded to be able to compete in the global market. Therefore, studies have been carried out using 1 hectare of land and the first generation of organic vetiver oil has produced 0.57% of yield, greater than non-organic (0.50%). The quality of organic and non-organic vetiver oil was analyzed by Indonesian Standard (SNI) parameter, pesticide residue test, chemical composition by GC/MS, and the appearance of vetiver root. In general, the result of organic and non-organic vetiver oil has fulfilled the national standard; the quality of organic vetiver oil was better than non-organic one. Physically, the appearance of organic vetiver root was better than non-organic vetiver root; organic vetiver root was denser, more appealing, and did not have any black spots. The pesticide residue of organic vetiver oil was lower than non-organic vetiver oil. Based on SNI test, vetiverol (oxygen compounds) in organic vetiver oil was higher than non-organic vetiver oil.
This research has purpose to describe Students science process skills by using hypothesis deductive learning cycle in learning buffer solutions. This research method was descriptive with the subjects were 40 second class Senior High School in Bandung. The students were categorized into high, medium, and low categories. Instruments of this research were student worksheets, observation sheets and interview. Based on this research, the students able to develop 10 indicators science process skills which. They are observing, classifying, planning experiments, questioning, hypothesizing, predicting, using tools and materials, interpreting, applying of concepts, and communicating. The results show that students in high category, medium category, and low category are able to develop 10 indicator.
Pada penelitian ini telah dilakukan pengawetan susu sapi segar menggunakan sistem laktoperoksidase dengan penambahan aktivator peroksidase. Konsentrasi aktivator peroksidase yang ditambahkan yaitu 10 ppm, 20 ppm, dan 30 ppm dengan suhu penyimpanan 4oC. Uji ketahanan susu dilakukan dengan uji resasurin dan Total Plate Count (TPC) petrifilm serta analisa kandungan protein pada susu yang diawetkan. Hasil uji resasurin dan TPC menunjukkan bahwa susu yang diawetkan dengan penambahan activator 30 ppm lebih tahan lama dibandingkan dengan penambahan aktivator 10 ppm dan 20 ppm. Kandungan protein susu sapi segar dan susu sapi yang di awetkan tidak mengalami perubahan secara signifikan yaitu berkisar 2,80 – 2,90 % b/b. Penambahan aktivator lektoperoksidase sampai 30 ppm dapat membuat susu lebih tahan lama.Kata Kunci : Sistem laktoperoksidase, aktivator, konsentrasi, resasurin, TPC.
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