Eti Rohaeti
Departemen Kimia, Fakultas Matematika dan Ilmu Pengetahuan Alam, Jl. Meranti, Kampus IPB Dramaga, Bogor, 16680, Indonesia

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Perlakuan Uap Panas (Vapor Heat Treatmant) untuk Disinfestasi Lalat Buah dan Mempertahankan Mutu Buah Belimbing (Averrhoa carambola L.) Rohaeti, Eti; Syarief, Rizal; Hasbullah, Rokhani
Jurnal Keteknikan Pertanian Vol 24, No 1 (2010): Jurnal Keteknikan Pertanian
Publisher : PERTETA

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Abstract The objectives of this research were to study mortality of carambola fruit fly (B. carambolae D & H) and to study responses of VHT on quality of carambola (A. carambola L). Fruit fly mortality due to heat has been investigated by immersing fruit fly eggs into hot water at temperatures of 40, 43, 46 dan 49oC for 30 minutes and then at temperature of 46.5oC for 0, 5, 10, 15, 20, 25, 30 minutes. Star fruit were treated at temperature of 46.5oC for 5, 15, 30 minutes and then stored in temperatures of 5, 15oC and room temperature (28-30 oC). The result show that mortality has been achieved 100% at temperature more than 43.0oC for 30 minutes and at temperature 46.0oC for more than 15 minutes. VHT had significant influences to decrease the fruit respiration rates, chilling injury, antraknose, to increase the weight loss, color, and soluble solid content. However, there were no significant change in the hardness, water content, vitamin C and organoleptic test. VHT at temperature 46.5oC for 20 up to 30 minutes were effective to kill fruit flies inside carambola and VHT combined by storing in temperature of 15oC were able to maintain carambola quality during storage. Keywords: vapor heat treatment, fruit fly, B. carambolae, carambola, disinfestation Diterima: 1 Februari 2010; Disetujui: 19 April 2010  
Perlakuan Uap Panas (Vapor Heat Treatment) untuk Disinfestasi Lalat Buah dan Mempertahankan Mutu Buah Belimbing (Averrhoa carambola L.) Rohaeti, Eti; Syarief, Rizal; Hasbullah, Rokhani
Jurnal Keteknikan Pertanian Vol 24, No 1 (2010): Jurnal Keteknikan Pertanian
Publisher : PERTETA

Show Abstract | Original Source | Check in Google Scholar | Full PDF (421.298 KB)

Abstract

AbstractThe objectives of this research were to study mortality of carambola fruit fly (B. carambolae D & H) and to study responses of VHT on quality of carambola (A. carambola L). Fruit fly mortality due to heat has been investigated by immersing fruit fly eggs into hot water at temperatures of 40, 43, 46 dan 49oC for 30 minutes and then at temperature of 46.5oC for 0, 5, 10, 15, 20, 25, 30 minutes. Star fruit were treated at temperature of 46.5oC for 5, 15, 30 minutes and then stored in temperatures of 5, 15oC and room temperature (28-30 oC). The result show that mortality has been achieved 100% at temperature more than 43.0oC for 30 minutes and at temperature 46.0oC for more than 15 minutes. VHT had significant influences to decrease the fruit respiration rates, chilling injury, antraknose, to increase the weight loss, color, and soluble solid content. However, there were no significant change in the hardness, water content, vitamin C and organoleptic test. VHT at temperature 46.5oC for 20 up to 30 minutes were effective to kill fruit flies inside carambola and VHT combined by storing in temperature of 15oC were able to maintain carambola quality during storage.Keywords: vapor heat treatment, fruit fly, B. carambolae, carambola, disinfestationDiterima: 1 Februari 2010; Disetujui: 19 April 2010
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
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.
Deteksi Simultan Kuersetin dan Rutin Menggunakan Screen-Printed Carbon Electrode Termodifikasi Grafena Elinda, Tamida; Wahyuni, Wulan Tri; Rohaeti, Eti
Jurnal Kimia Valensi Jurnal Kimia VALENSI Volume 5, No. 1, Mei 2019
Publisher : Department of Chemistry Faculty of Sciences and Technology UIN Jakarta

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Abstract

Kuersetin dan rutin merupakan senyawa antioksidan alami yang termasuk golongan flavonoid. Senyawa ini dapat dideteksi dengan beberapa teknik analisis, salah satunya dengan teknik elektrokimia. Pada penelitian ini, deteksi simultan kuersetin dan rutin dilakukan dengan teknik voltametri siklik menggunakan screen printed carbon electrode (SPCE) termodifikasi grafena. Elektrode disiapkan melalui modifikasi elektrode kerja SPCE dengan campuran grafena:natrium poliakrilat (1:1). Larutan etanol 70%:bufer fosfat pH 7 (6:4) digunakan sebagai elektrolit dalam pengukuran kuersetin dan rutin. Hasil penelitian menunjukkan puncak oksidasi kuersetin dan rutin terdeteksi pada potensial 0.179 V dan 0.310 V vs Ag/AgCl. SPCE termodifikasi grafena menghasilkan intensitas arus oksidasi dan sensitivitas yang lebih tinggi pada pengukuran kuersetin dan rutin. Deteksi simultan kuersetin dan rutin menggunakan SPCE termodifikasi grafena menunjukkan linearitas dengan R2 = 0.9905 dan R2 = 0.9816, masing-masing untuk kuersetin dan rutin. Limit deteksi pengukuran kuersetin dan rutin masing-masing sebesar 0.5369 mM dan 0.7495 mM serta limit kuantitasi sebesar 1.7898 mM dan 2.4985 mM. Presisi pengukuran kuersetin dan rutin memiliki nilai simpangan baku relatif (%SBR) sebesar 2.14% dan 2.44%, berturut-turut untuk kuersetin dan rutin. Hal ini menunjukkan bahwa SPCE termodifikasi grafena cukup potensial untuk deteksi simultan kuersetin dan rutin secara elektrokimia. Kata kunci: Grafena, kuersetin, rutin, screen printed carbon electrode, voltametri siklik. Quercetin and rutin are natural antioxidant from flavonoid group. The compounds can be detected using several analytical technique, including electrochemical technique due to its redox activity. In this study, simultaneous detection of quercetin and rutin was performed at graphene-modified screen printed carbon electrode (SPCE) using cyclic voltammetry technique. Graphene-modified SPCE was prepared from mixture of graphene:sodium polyacrylate (1:1) via drop casting method. Ethanol 70%:phosphate bufer pH 7 (6:4) was used as electrolyte solution for quercetin and rutin measurement. The result shows that oxidation peak of quercetin and rutin was detected at potential of 0.179 V and 0.310 V vs Ag/AgCl, respectively. Graphene-modified SPCE produce higher intensity of oxidation current and higher sensitivity for quercetin and rutin measurement. Simultaneous detection of quercetin and rutin at graphene modified SPCE provide linearity with R2 = 0.9905 and R2 = 0.9816, respectively for quercetin and rutin. Detection limits of quercetin and rutin respectively was 0.5369 mM and 0.7495 mM while limit quantitation was 1.7898 mM dan 2.4985 mM. Precision of quercetin and rutin measurement was moderate with percent relative standard deviation (%RSD) of 2.14% and 2.44%, consecutively for quercetin and rutin. This suggests that graphene-modified SPCE is potential for simultaneous electrochemical detection of quercetin and rutin. Keywords: Cyclic voltammetry, graphene, quercetin, rutin, screen printed carbon electrode.
A Simple Photometer and Chemometrics Analysis for Quality Control of Sambiloto (Andrographis paniculata) Raw Material Heryanto, Rudi; Permana, Derry; Tedjo, Aryo; Rohaeti, Eti; Rafi, Mohamad; Darusman, Latifah Kosim
The Journal of Pure and Applied Chemistry Research Vol 6, No 3 (2017): Edition of September - December 2017
Publisher : Chemistry Department, The University of Brawijaya

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In this paper, we described the use of a light emitting diode (LED)-based photometer and chemometric analysis for quality control of king of bitter or sambiloto (Andrographis paniculata) raw material. The quality of medicinal plants is determined by their chemical composition. The quantities of chemical components in medicinal plants can be assessed using spectroscopic technique. We used an “in house” photometer to generate spectra of sambiloto. The spectra were analyzed by chemometric methods, i.e. principal component analysis (PCA) and partial least square discriminant analysis (PLS-DA), with the aim of herbal quality classification based on the harvesting time. From the results obtained, based on thin layer chromatography analysis, sambiloto with different collection times (1, 2, and 3 months) contained different amounts of active compounds. Evaluation of sambiloto, using its spectra and chemometric analysis has successfully differentiated its quality based on harvesting time. PCA with the first two PC’s (PC-1 = 60% and PC-2 = 35%) was able to differentiate according to the harvesting time of sambiloto. Three models were obtained by PLS-DA and could be used to predict unknown sample of sambiloto according to the harvesting time
L-Histidine-Modified Silica from Rice Husk and Optimization of Adsorption Condition for Extractive Concentration of Pb(II) Nurhajawarsi, Nurhajawarsi; Rafi, Mohamad; Syafitri, Utami Dyah; Rohaeti, Eti
The Journal of Pure and Applied Chemistry Research Vol 7, No 2 (2018): Edition May-August 2018
Publisher : Chemistry Department, The University of Brawijaya

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Abstract

A new chelating agent, L-histidine-modified silica from rice husk (LHSRH), was prepared to increase the adsorption capacity and selectivity for Pb(II). LHSRH was synthesized by immobilizing L-histidine on silica from rice husk (RH) modified with 3-aminopropyltrimethoxysilane (APTMS). Silica from rice husk (SRH) was synthesized via precipitation process by adding hydrochloric acid solution to rice husk ash (RHA). The RHA was subsequently destructed with sodium hydroxide and heated to obtain sodium silicate (Na2SiO3). SRH was characterized by Fourier transform infrared spectroscopy and x-ray diffraction. The LHSRH was used further to adsorp Pb(II) metal ion. The pH range, amount of adsorbent, and adsorption time were optimized by response surface methodology. The optimum condition for the adsorption of Pb(II) was pH 5, an amount of adsorbent 0.1 g; and adsorption time 15 minutes. The adsorption capacity for Pb(II) ion was found to be 62.5 mg/g. The adsorption behavior of the matrix followed the Langmuir’s model.
Sintesis Dan Karakterisasi Natrium Silikat (Na2SiO3) Dari Sekam Padi Trivana, Linda; Sugiarti, Sri; Rohaeti, Eti
Jurnal Sains & 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 logam pengotor. Kandungan silika yang tinggi pada abu sekam padi dapat digunakan sebagai alternatif sumber silika yang potensial dalam sintesis natrium silikat. Natrium silikat murni disintesis melalui dua tahap, yaitu isolasi silika dari sekam padi dan sintesis natrium silikat. Isolasi silika terdiri atas proses pengarangan, pengabuan arang sekam pada suhu 600°C, selama 2 jam dan pemurnian silika dengan HCl 3%. Natrium silikat disintesis dengan cara destruksi dengan NaOH yang diikuti dengan peleburan. Natrium silikat yang diperoleh akan dikarakterisasi dengan teknik FTIR untuk 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 muncul umumnya adalah gugus silanol (≡Si-OH) dan siloksan (≡Si-O-Si≡). Pita serapan di 2800-3750 cm-1 menunjukkan gugus –OH silanol dan H2O yang diserap. Bilangan gelombang 682,8 cm-1 menunjukkan ikatan Si-O-Si dan vibrasi ulur Si-O pada silanol (≡Si-OH) pada bilangan gelombang 972,12 cm-1. Hasil EDS menunjukkan bahwa unsur-unsur yang terdapat dalam natrium silikat sintetis, yaitu oksigen 71,89%, natrium 22,63%, dan silikon 5,39%.
SYNTHESIS OF ZEOLITE AND COMPOSITE OF ZEOLITE/TiO2 FROM KAOLIN AND ITS APLICATION TO ADSORPTION-PHOTODEGRADATION OF METHILEN BLUE Trivana, Linda; Sugiarti, Sri; Rohaeti, Eti
ALCHEMY Jurnal Penelitian Kimia Vol 11, No 2 (2015): Alchemy Jurnal Penelitian Kimia
Publisher : UNIVERSITAS SEBELAS MARET (UNS)

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In this study, zeolite was synthesized from kaolin which was founded from Bangka Belitung as the starting material. Meanwhile, sodium silicate was used as silica source. Zeolite is material with many benefits, such as become an adsorbent. Kaolin has been used as starting material due to high content of silica and alumina, i.e 35 - 50 %. Zeolite was prepared by hydrothermal synthesis process, by mixing the metakaolin which was produced by calcination of kaolin at 700 °C for 6 hours, with sodium silicate and NaOH. The NaOH was used to activate the major components of Si and Al in the kaolin.The hydrothermal process was conducted at 100 °C for 24 hours with various concentrations of NaOH, i.e 1.5 N and 2.5 N. The NaOH concentration might determine the type of zeolite obtained. To improve the nature as adsorbent, zeolites modified into zeolit/TiO2. The addition of TiO2into the prepared zeolit aimed to produce a material with capability as adsorbent-photocatalyst. The result of research found that the addition of NaOH 1.5 N produced zeolite NaP1. Meanwhile, the addition of NaOH 2.5 N produced the NaP1 zeolite, zeolite X, and faujasite. The composite of zeolit/TiO2has ability on adsorption-photocatalytic as it was proven by methylene blue degradation under ultraviolet light.
CARBON PASTE ELECTRODE HEXADECYLTRIMETHYLAMMONIUM BROMIDE MODIFIED NATURAL ZEOLITE FOR CHROMIUM(VI) DETECTION Putra, Budi Riza; Darusman, Latifah K; Rohaeti, Eti
Indonesian Journal of Chemistry Vol 13, No 2 (2013)
Publisher : Universitas Gadjah Mada

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A simple voltammetric technique for quantification of chromium(VI) is presented in this work. The technique is based on linear sweep voltammetric reduction Cr(VI) on hexadecyltrimethylammonium bromide (HDTMABr) modified Lampung zeolite carbon paste electrode. Selected HDTMABr concentration for natural zeolite modification is obtained 200 mM. Working electrode for chromium(VI) detection is made by graphite, paraffin oil and HDTMABr modified Lampung zeolite. The effect of supporting electrolyte matrix, pH and also scan rate is also investigated. The calibration curve for chromium(VI) detection using the proposed method shows linearity from 0.2 to 1.0 mM with sensitivity, detection and quantification limit, and precision was 0.4294 mM, 3.63 x 10-4 mM, 1.197 x 10-3 mM, 4.49%, respectively.