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MODIFIKASI SCREEN PRINTED CARBON ELECTRODE DENGAN POLIMER TERCETAK MOLEKUL (MIP) DAN APLIKASINYA UNTUK DETEKSI GLUTATION Eti Rohaeti; Wulan Tri Wahyuni; Moh Arif Rohman Nur Hakim
Analit: Analytical and Environmental Chemistry Vol 3, No 1 (2018): Analit: Analytical and Environmental Chemistry
Publisher : Universitas Lampung Jl. Prof. Dr. Sumatri Brojonegoro No.1 Bandar Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/aec.v3i1.2018.p

Abstract

Penelitian ini bertujuan memodifikasi screen printed carbon electrode (SPCE)  dengan polimer tercetak molekul (MIP) dan mengaplikasikannya untuk deteksi glutation tereduksi (GSH) secara tidak langsung dengan mediator bromin menggunakan teknik voltammetri siklik. SPCE dimodifikasi dengan MIP polipirola (MIPpy) melalui teknik elektrodeposisi. Pengukuran GSH dilakukan dalam elektrolit NaClO4 0.2 M yang mengandung 1 mM NaBr. Hasil yang diperoleh menunjukkan SPCE-MIPpy telah berhasil diperoleh melalui teknik elektrodeposisi. Pada pengukuran diperoleh puncak oksidasi bromida pada potensial ±0.63 V vs. Ag/AgCl. Puncak ini berkorelasi linear dengan konsentrasi GSH dalam larutan sehingga dapat digunakan sebagai dasar penentuan GSH. Polipirola meningkatkan konduktivitas listrik elektrode sehingga dapat meningkatkan puncak arus oksidasi GSH. Pengukuran glutation dengan SPCE-MIPpy menunjukkan limit deteksi dan limit kuantitasi yang lebih baik dibandingkan SPCE, yaitu sebesar 7.6626 µM dan 25.4092 µM. Keberadaan interference glukosa tidak mengganggu pengukuran glutation. Kinerja SPCE-MIPpy dalam pengukuran GSH disimpulkan lebih optimum dibandingkan SPCE.  DOI: http://dx.doi.org/10.23960/aec.v3.i1.2018.p47-60 
Kajian Efisiensi Energi Proses Penyulingan Dan Sifat Fisik Hasil Penyulingan Minyak Serai Dapur Menggunakan Tungku Sekam Dan Heating Mantel Rohaeti, E.; Pamungkas, N. G.; Irzaman, Irzaman
BERKALA FISIKA Vol 13, No 2 (2010): Berkala Fisika, Edisi Khusus
Publisher : BERKALA FISIKA

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Abstract

Essential oil distillation has been carried out from the lemongrass material using two heaters there are rice husk and heating mantel. In comparison ingredients (lemongrass: water = 0.125 kg: 0.5 liters) distillation with rice husk heater requires energy 6022.5 kcal, 3660 second distillation time, costs Rp 912.5 with an average rendemen of oil produced 0.0635 %. Distillation with the same material amount using heating mantel requires the energy 832.143 Kcal, distillation time 6990 seconds, the cost Rp 608.6 and producing the rendemen 0.114%. Distillate debit is influenced by the heat generated which produced by the rice husk and heating mantel. The quality of lemongrass oil which produced by the rice husk heating is better than the heating mantel in term of the lemongrass oil color and oil refractive index. Lemongrass oil which is produced by the pale brown of heating rice husk and refractive index values were in the range of 1.4830 to 1.4890. Keywords: rice husk, heating mantel, distillation, lemongrass oil, energy.
Sintesis Dan Karakterisasi Natrium Silikat (Na2SiO3) Dari Sekam Padi Trivana, Linda; Sugiarti, Sri; Rohaeti, Eti
Jurnal Sains Dan Teknologi Lingkungan Vol 7, No 2 (2015): SAINS & TEKNOLOGI LINGKUNGAN
Publisher : Teknik Lingkungan Universitas Islam Indonesia

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Abstract

Abu sekam padi umumnya mengandung silika (SiO2) sebesar 86,90-97,30% dan sejumlah kecil alkali dan logampengotor. Kandungan silika yang tinggi pada abu sekam padi dapat digunakan sebagai alternatif sumber silika yangpotensial dalam sintesis natrium silikat. Natrium silikat murni disintesis melalui dua tahap, yaitu isolasi silika darisekam padi dan sintesis natrium silikat. Isolasi silika terdiri atas proses pengarangan, pengabuan arang sekam padasuhu 600°C, selama 2 jam dan pemurnian silika dengan HCl 3%. Natrium silikat disintesis dengan cara destruksidengan NaOH yang diikuti dengan peleburan. Natrium silikat yang diperoleh akan dikarakterisasi dengan teknik FTIRuntuk analisis gugus fungsional dan EDS untuk analisis komposisi serta kadar unsur yang terkandung dalam sampel.Analisa FTIR sampel natrium silikat membuktikan terjadinya pembentukan SiO2. Pola serapan silika yang munculumumnya adalah gugus silanol (≡Si-OH) dan siloksan (≡Si-O-Si≡). Pita serapan di 2800-3750 cm-1 menunjukkangugus –OH silanol dan H2O yang diserap. Bilangan gelombang 682,8 cm-1 menunjukkan ikatan Si-O-Si dan vibrasiulur Si-O pada silanol (≡Si-OH) pada bilangan gelombang 972,12 cm-1. Hasil EDS menunjukkan bahwa unsur-unsuryang terdapat dalam natrium silikat sintetis, yaitu oksigen 71,89%, natrium 22,63%, dan silikon 5,39%.Kata Kunci : sekam padi, silikat, natrium silika, FTIR, EDX
SCALING UP OF THE PYROLYSIS PROCESS TO PRODUCE SILICA FROM RICE HUSK Irzaman, Irzaman; Rohaeti, Eti; Hadjomidjojo, Hartrisari; Casnan, Casnan; Noor, Erliza
Journal of Engineering and Technological Sciences Vol 51, No 6 (2019)
Publisher : ITB Journal Publisher, LPPM ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2019.51.6.1

Abstract

Rice husk is a potential alternative source of silica and silicon. The mechanism of heating (pyrolysis) for the decomposition of rice husk is an important factor in obtaining silica of high purity. Medium-scale pyrolysis to produce silica from rice husk serves as a bridge to connect laboratory-scale production to industrial-scale production. The purpose of this study was to model and scale up the pyrolysis process as a guidance for industrial-scale production. The research method used was experimentally based. An experimental investigation was undertaken in five stages. 1) Analyzing rice husk mass conversion using thermogravimetry analysis (TGA); 2) pyrolysis modeling based on a laboratory investigation using COMSOL Multiphysics version 5.3; 3) medium-scale experiments according to the modeling results; 4) validation of the modeling results by carrying out a medium-scale experiment; 5) silica purity analysis using SEM-EDX. The medium-scale pyrolysis simulation of silica manufacture from rice husk obtained a heating rate of 1.5 °C/min. There was an increase in the heating rate of 1 °C/min when compared to the laboratory-scale process. The pyrolysis of rice husk for the production of silica affects the mass conversion and selectivity of the resulting silica product. The mass conversion produced was 13.33% to 17.87% and the purity of silica produced was 63.99% to 82.74%.
Hubungan Lama Distilasi, Kandungan Senyawa, dan Bioautografi Antioksidan Minyak Atsiri Bangle (Zingiber purpureum) Irmanida Batubara; Rahadyanoto Trimulia; Eti Rohaeti; Latifah K Darusman
INDONESIAN JOURNAL OF ESSENTIAL OIL Vol 3, No 1 (2018)
Publisher : Institut Atsiri Universitas Brawijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (301.695 KB)

Abstract

Bangle (Zingiber purpureum) merupakan salah satu tanaman obat yang mengandung minyak atsiri. Untuk mengambil minyak atsiri dari rimpang bangle dapat dilakukan distilasi dengan perbedaan lama distilasi. Tujuan penelitian ini adalah menentukan kadar minyak atsiri dari rimpang bangle dan membandingkan kandungan senyawanya berdasarkan waktu distilasi yang berbeda. Minyak atsiri bangle didistilasi dengan perbedaan rentang waktu, yaitu 0-3 jam, 3-6 jam, dan 6-9 jam. Rendemen minyak atsiri yang diperoleh berbeda walaupun selang waktu yang digunakan sama. Kadar senyawa minyak atsiri berbeda bergantung pada lama waktu distilasi. Perbedaan tersebut ditentukan melalui kromatografi gas-spektrometri massa. Kandungan senyawa sabinena optimum pada waktu distilasi 0-3 jam, osimena pada rentang waktu 3-6 jam, dan naftalena pada rentang waktu 6-9 jam. Profil kromatografi lapis tipis dan bioautografi antioksidan terhadap DPPH untuk ketiga minyak juga ditentukan.
SINTESIS ADSORBEN ZEOLIT@AuNPs@MET MENGGUNAKAN EKSTRAK DAUN BINAHONG (Anredera cordifolia) SEBAGAI BIOREDUKTOR PREKURSOR Au DAN KARAKTERISASINYA (Synthesis Zeolite@AuNPs@MET Adsorbent by Binahong (Anredera cordifolia) Leaf Extract as Au Precursor Bioreduc Nurdiani, Nurdiani; Darusman, Latifah K.; Rohaeti, Eti
Jurnal Hasil Penelitian Industri Vol 28, No 1 (2015)
Publisher : Baristand Industri Banda Aceh

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Abstract

Modifying zeolite with Au nanoparticles and mercaptoethanol ligand(zeolite@AuNPs@MET) has been developed as an adsorbent of heavy metal ions. The preparation ofzeolite@AuNPs@MET composite material was done in three steps. Firstly, incorporating gold precursorin to zeolite cavity. Secondly, reduction of gold nanoparticles by binahong leaf extract. Thirdly, modifyingzeolite@AuNPs with mercaptoethanol ligand. Binahong was used as bioreductor agent in the synthesis ofAu nanoparticles since it has large contents of flavonoids, saponins, tannins, and steroids which containreducing functional group. The zeolite@AuNPs@MET composite material was characterized by XRD,EDX, PSA, TEM, FTIR and UV Visible Spectrophotometer. EDX measurements showed Au content of0.88%, TEM and PSA measurement showed Au nanoparticle size in the range of 7.12 nm to 14.45 nmwith an average size distribution of 110.6 nm while gold nanoparticles immobilized in the pores ofzeolites have sizes ranging from 4.98 nm to 9.50 nm with an average size distribution of 279 nm. UVVisible absorption spectrum revealed a new formed peak at 537 nm, indicating formation of AuNPs. The characteristic peaks (at 526 nm and 532 nm) were also found in the UV-Vis absorption spectrum ofAuNPs immobilized in the zeolite pores and AuNPs in the zeolite@AuNPs@MET composite, respectively.FTIR measurements of mercaptoethanol ligand showed the presence of a peak at 2550 cm-1 regionindicating SH functional groups, which disappeared after modification of zeolite@Au with MET ligand,indicated the –SH bond was broken and the remained –S was attached to AuNPs. All of thecharacterization revealed the success of the composite material preparation, which is an interestingmaterial expected to have highly potential as a heavy metal ion adsorbent.
Differentiation of Curcuma longa, Curcuma xanthorrhiza and Zingiber cassumunar by Thin Layer Chromatography Fingerprint Analysis Mohamad Rafi; Eti Rohaeti; Ali Miftahudin; Latifah K. Darusman
Indonesian Journal of Chemistry Vol 11, No 1 (2011)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (748.207 KB) | DOI: 10.22146/ijc.21423

Abstract

Turmeric (Curcuma longa), java turmeric (Curcuma xanthorrhiza) and cassumunar ginger (Zingiber cassumunar) are widely used in traditional Indonesian medicine. These three herbs have relatively similar rhizomes colour so it is difficult to be differentiated especially if they are in powder form. A rapid and reliable method, thin layer chromatography (TLC) fingerprint, has been developed in order to identify, authenticate and differentiate these three herbs through fingerprint profile of chemical compounds. TLC fingerprints of the three herbs were obtained by visualization of separate zones with visible and UV (254 and 366 nm) light. The TLC fingerprint pattern is different each other and showed a specific marker zones respectively. Therefore, TLC fingerprint can be utilized for identification, authentication and differentiation method in quality control of the three herbs tested.
PENGGUNAAN METODE HOMOTOPI PADE’ UNTUK MENYELESAIKAN MASALAH LOTKA-VOLTERRA E. ROHAETI; J. JAHARUDDIN; A. KUSNANTO
MILANG: Journal of Mathematics and Its Applications Vol. 11 No. 1 (2012): Journal of Mathematics and Its Applications
Publisher : Dept. of Mathematics, IPB University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29244/jmap.11.1.31-40

Abstract

Model Lotka- Volterra merupakan model interaksi antar spesies mangsa dan spesies pemangsa pada sebuah lingkungan dan dinyatakan dalam bentuk persamaan taklinear. Persamaan Lotka-Volterra diselesaikan dengan metode homotopi Pade'. Metode hemotopi Pade' merupakan pengembangan dari metode homotopi. Dalam hal ini, penyelesaian dengan menggunakan metode homotopi Pade' diperoleh dengan menggunakan penyelesaian dengan menggunakan metode homotopi. Metode homotopi Pade’ lebih cepat mencapai kekonvergenan dibandingkan dengan metode homotopi. Dengan metode homotopi Pade' diberikan suatu interpretasi fisis untuk kasus mangsa lebih banyak dari pemangsa.
Gum Benzoin (Styrax benzoin) as Antibacterial against Staphylococcus aureus Asih Gayatri; Eti Rohaeti; Irmanida Batubara
Al-Kimia Vol 7 No 2 (2019): DECEMBER
Publisher : Study Program of Chemistry - Alauddin State Islamic University of Makassar

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (474.648 KB) | DOI: 10.24252/al-kimia.v7i2.10581

Abstract

Gum benzoin (Styrax benzoin) is one of nontimber forest product classified into the resin group. The aim of the study was to determine the component from gum benzoin as an antibacterial against Staphylococcus aureus. Indonesian gum benzoin was obtained from North Sumatra and has antibacterial activity against S. aureus with the MIC (minimum inhibitory concentration) and MBC (minimum bactericidal concentrationo) values of its ethyl acetic extract of 1.00 mg/mL and 2.00 mg/mL, respectively. Thin layer chromatography (TLC) was used in purification of ethyl acetate extract of the gum benzoin. The active component was detected by TLC contact bioautography. The bands with Rf of 0.21, 0.77, and 0.87 had growth inhibition activity to the S. aureus. The active antibacterial band with Rf of 0.21 was isolated and it could be an alkaloid component.
AKTIVITAS ANTIBAKTERI DAN TOKSISITAS MINYAK SERAI DAPUR (Cymbopogon citratus) DENGAN PERLAKUAN PEMEKATAN PADA SUHU BERBEDA Reni Febriani; Eti Rohaeti; Wulan Tri Wahyuni
Analit: Analytical and Environmental Chemistry Vol 6, No 2 (2021): Analit: Analytical and Environmental Chemistry
Publisher : Universitas Lampung Jl. Prof. Dr. Sumatri Brojonegoro No.1 Bandar Lampung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.23960/aec.v6i2.2021.p168-179

Abstract

Minyak atsiri serai (Cymbopogon citratus) dapur telah dipergunakan secara luas di berbagai industri, diantaranya sebagai agen antibakteri. Pada penelitian ini dievaluasi aktivitas antibakteri dan toksisitas minyak serai dapur yang dipekatkan pada suhu berbeda. Toksisitas dievaluasi melalui uji brine shrimp lethality test (BSLT), sementara uji antibakteri dilakukan terhadap bakteri Staphylococcus aureus dan S. epidermidis dengan metode difusi dan dilusi. Komponen kimia yang terdapat dalam minyak serai dianalisis menggunakan kromatografi gas spektrometri massa (GC-MS). Hasil yang diperoleh menunjukkan berdasarkan uji BSLT diperoleh nilai lethal concentration 50 (LC50) sampel minyak serai dapur semua perlakuan < 1000 ppm dengan LC50 terendah sebesar 16,53 ± 2,82 ppm. Nilai konsentrasi hambat minimun (KHM) dan konsentrasi bunuh minimum (KBM) minyak serai dapur terhadap S. aureus umumnya lebih rendah dibanding terhadap S. epidermidis. Aktivitas antibakteri minyak serai dapur terhadap S. aureus terkategori sangat kuat dengan nilai KHM dan KBM terendah ditunjukkan oleh minyak serai tanpa perlakuan pemekatan yaitu sebesar 1250 dan 2500 ppm terhadap S. aureus. Komposisi senyawa kimia utama dalam minyak serai dapur berdasarkan analisis GC-MS ialah sitral, neral dan β-myrcenehttp://dx.doi.org/10.23960/aec.v6.i2.2021.p168-179