Dwiarso Rubiyanto | Universitas Islam Indonesia (original) (raw)

Conference Presentations by Dwiarso Rubiyanto

Minyak atsiri merupakan jenis minyak yang diperoleh dari tanaman. Untuk membedakan minyak atsiri ... more Minyak atsiri merupakan jenis minyak yang diperoleh dari tanaman. Untuk membedakan minyak atsiri dengan jenis minyak nabati ada beberapa sifat yang harus diperhatikan. Minyak atsiri memiliki bau yang khas sesuai jenis tanamannya; ada yang harum lembut, ada yang menyengat bahkan bau tidak enak bagi yang sensitif penciumannya. Jadi bila dihadapkan pada kita dua jenis minyak dari tumbuhan, cukup mudah membedakan mana yang minyak atsiri dan mana yang minyak nabati, yaitu dari baunya. Hampir semua minyak nabati tidak berbau, kecuali yang terdegradasi atau rusak (rancid). Minyak nabati merupakan istilah khusus untuk minyak dari tanaman yang mengandung trigliserida. sementara minyak atsiri merupakan salah satu jenis bahan yang berbentuk minyak yang tersusun oleh campuran senyawa organik yang sebagian besar digolongkan ke dalam senyawa terpenoid.
Senyawa ini dicirikan oleh adanya ikatan lima karbon yang membentuk kerangka isoprenoid. Kerangka isoprenoid dapat berupa ikatan jenuh (isopentana) atau ikatan tak jenuh (isopentena). Dalam susunannya, kerangka isoprenoid dapat membentuk kelompok terpenoid yang berbeda yaitu monoterpen (10 karbon), seskuiterpen (15 karbon), diterpen (20 karbon), triterpen (30 karbon) dan tetraterpen (40 karbon).

Papers by Dwiarso Rubiyanto

Nucleation and Atmospheric Aerosols, 2021

This work studied the use of chitosan-based edible coatings enriched with essential oils to impro... more This work studied the use of chitosan-based edible coatings enriched with essential oils to improve storability of strawberries. It was started by analysis of the essential oil (Lemongrass oil and Basil oil) by gas chromatography-mass spectrometry. The main constituent of those essential oils was citral, as an antifungal activity. The edible coatings based on chitosan (CT), chitosan-lemongrass oil (CT-LO), and chitosan-basil oil (CT-BO). Thus, in this work CT, CT-LO, and CT-BO were elaborated and applied to fresh strawberries, and its effect on the strawberries shelf life during storage for 15 days was evaluated by fungal decay. The concentrations of essential oils were 0.25%, 0.5%, 0.75%, 1%, 1.25%. The edible coatings have been shown to prolong the storage life of strawberries

INDONESIAN JOURNAL OF CHEMICAL RESEARCH, 2020

Isolasi dan identifikasi sifat fisika-kimia minyak atsiri bunga kenanga (Cananga odorata) segar d... more Isolasi dan identifikasi sifat fisika-kimia minyak atsiri bunga kenanga (Cananga odorata) segar dan layu telah dilakukan dalam penelitian ini. Minyak atsiri bunga kenanga diisolasi dengan metode destilasi uap. Komponen kimia dari dua kondisi bahan bunga kenanga dianalisis menggunakan instrumen GCMS. Beberapa parameter fisika meliputi uji warna, bau, berat jenis dan indeks bias dilakukan dalam penelitian ini. Hasil analisis diketahui rendemen minyak atsiri pada bunga kenanga segar dan layu masing-masing adalah 0,325%(b/b) dan 0,276%(b/b). Komponen senyawa kimia utama yaitu 1-metoksi-4-metil benzena (3,05%) linalool (22,06%), geranil asetat (7,54%), trans-kariofilen (28,06%),a-humulen (8,65%) dan D-germacren (21,91%), sedangkan penyusun minyak kenanga layu adalah 1-metoksi-4-metil benzena (2,79%), linalool (21,76%), trans-kariofilen (31,87%), a-humulen (9,25%) dan D-germacren (21,62%). Hasil uji sifat fisika-kimia minyak bunga kenanga segar berwarna kuning bening, bau harum kenanga, b...

Indonesian journal of essential oil, Nov 1, 2016

Telah dilakukan penelitian secara eksperimen laboratorium tentang isolasi sitral yang merupakan k... more Telah dilakukan penelitian secara eksperimen laboratorium tentang isolasi sitral yang merupakan komponen terbesar dari minyak kemangi (Ocimum citriodorum, L). Minyak kemangi dapat diisolasi dari tanaman kemangi dengan penyulingan uap (steam distillation). Rendemen minyak kemangi hasil penyulingan sebesar 0,2 % b/b. Hasil kromatogram minyak kemangi (Ocimum citriodorum, L) menunjukkan konsentrasi sitral sebesar 33,82% dengan komposisi cis-sitral sebesar 14,86% dan trans-sitral sebesar 18,96%. Dalam penelitian ini sitral dalam minyak kemangi diisolasi dengan dua metode yaitu metode ekstraksi bisulfit dan metode distilasi uap. Isolasi sitral dengan metode ekstraksi bisulfit dilakukan secara kimia dengan mereaksikannya dengan larutan jenuh Natrium Bisulfit (NaHCO3) sementara isolasi sitral dengan metode distilasi uap dilakukan dengan rangkaian alat gelas kimia skala 500 mL. Isolasi sitral dengan metode distilasi uap dilakukan dengan perbandingan minyak kemangi dan air

3rd INTERNATIONAL SEMINAR ON SCIENCE AND TECHNOLOGY (ISSTEC) 2021: Science, Technology and Data Analysis for Sustainable Future

IJCR : Indonesian Journal of Cemical Research, Jun 2, 2018

Chemical engineering transactions, Mar 20, 2017

Slow release fertiliser (SRF) is one of the important materials, which provides benefit to the gr... more Slow release fertiliser (SRF) is one of the important materials, which provides benefit to the green chemistry and green chemical engineering in the agricultural applications. Various modifications on porous materials and super-adsorbent based composites have been developed to act as the host for fertilisers including nitrogenbased fertilisers. In this work, a scheme of organic nitrogen compound, methenamine, was used as the SRF compound and in order to increase the effectivity of the releasing nitrogen, immobilisation of the compound in montmorillonite clays has been conducted. Methenamine immobilised montmorillonite at varied methenamine contents (20 mmol/g; 50 mmol/g and 100 mmol/g) was prepared using intercalation process by employing microwave irradiation method. Study on the change of crystallinity and chemical structure of the composite was performed by x-ray diffraction (XRD) analysis, gas sorption analyser, and electronic microscope analysis. The kinetic study of the nitrogen release was conducted by FTIR and HPLC methods. Results showed that physicochemical character of the composite is affected by the methenamine content and the pH of the solution gives influence on the methenamine desorption from the composite.

Nucleation and Atmospheric Aerosols, 2022

Green capping agent and green sensitizer of TiO 2 for photocatalytic activity: Mini review

Jurnal Penelitian Saintek, 2013

Telah dilakukan reaksi tandem hidrogenasi-siklisasi menuju menthol dari citronellal secara satu t... more Telah dilakukan reaksi tandem hidrogenasi-siklisasi menuju menthol dari citronellal secara satu tahap dengan variasi metode berkatalis ZrO 2 montmorillonite (Zr-MMT). Tujuan penelitian adalah untuk menentukan keefektifan katalis Zr-MMTT dengan dua metode: metode dengan sistem flow terhadap campuran sitronellal-katalis setelah refluks dengan tekanan H 2 sebesar 3 kPa dan metode yang lain sistem flow terhadap campuran sitronellalkatalis pada 200 o C dengan tekanan H 2 2kPa. Hasil reaksi dianalisis menggunakan GC-MS dengan menentukan total konversi dan rendemen mentol. Hasil menunjukkan bahwa metode yang berbeda memberikan mekanisme reaksi yang signifikan. Metode pertama memberikan konversi sebesar 99% dengan produk utama isomenthon dan isopulegol sedangkan metode ke dua memberikan nilai konversi 5,18% dengan selektifitas sebesar 0,39% terhadap menthol. Dibandingkan dengan montmorillonit alam, kedua proses memberikan nilai konversi lebih besar dimana konversi menggunakan montmorillonit kurang dari 5%. Ketercukupan laju H 2 sebagai reaktan adalah faktor penting dalam menentukan mekanisme.

Nucleation and Atmospheric Aerosols, 2018

There are several challenges arose in the conduct of subjects which are supported with the labora... more There are several challenges arose in the conduct of subjects which are supported with the laboratory (lab) works as it was found in the course of Chromatography in the Study Program of Chemistry, Universitas Islam Indonesia. Firstly, the theoretical aspects in this course which are delivered in the class lecture were considered very broad and including various types of chromatography, in which not all of these could be applied for the lab work materials. Secondly, the chromatography lab work was conducted in the same semester with the course and the lab work series which was usually finished earlier than the class lecture. Lastly, the greatest difficulty faced by the students when they obtained data from the lab activities and they had to perform interpretation and analysis based on the results of the chromatography analysis to be written into the final lab report. Therefore in order to solve these problems, a new method containing learning activities in class which was designed in this research to synchronize the chromatographic course and the lab work was applied. The activity designed for the synchronization process in this research involved the application of problem based learning (PBL) method based on learning scenarios. Students were guided to extract some problems from the experiment performed in the lab especially those related to the analysis and interpretation of the data resulted followed by group discussion. After completing the task, on each schedule of class activity material related to the lab work material, some of the groups who had obtained the related topic in the lab work explained the problems they dealt with as well as the solutions they obtained to interpret the results of their analysis. At the end of the class activity, lecturer confirmed what the presenters in each group were delivered. Afterwards, the lecturer should explain the chromatographic material in accordance with the course outline.There are several challenges arose in the conduct of subjects which are supported with the laboratory (lab) works as it was found in the course of Chromatography in the Study Program of Chemistry, Universitas Islam Indonesia. Firstly, the theoretical aspects in this course which are delivered in the class lecture were considered very broad and including various types of chromatography, in which not all of these could be applied for the lab work materials. Secondly, the chromatography lab work was conducted in the same semester with the course and the lab work series which was usually finished earlier than the class lecture. Lastly, the greatest difficulty faced by the students when they obtained data from the lab activities and they had to perform interpretation and analysis based on the results of the chromatography analysis to be written into the final lab report. Therefore in order to solve these problems, a new method containing learning activities in class which was designed in this research to synch...

Bulletin of Chemical Reaction Engineering & Catalysis, Nov 13, 2019

Green conversion in organic synthesis is one of the interesting and important topics in green che... more Green conversion in organic synthesis is one of the interesting and important topics in green chemistry. The use of heterogeneous catalysis instead of homogeneous catalysis offers some advantages, such as easy separation and reusability. In this research, a heterogeneous acid catalyst was prepared from saponite by immobilizing ZnO in the form of a pillared clay (Zn/PILS) and Zn supported on porous clay heterostructure (Zn/PCH). Physicochemical studies involving X-ray diffraction measurement, surface analysis using a gas sorption analyzer, and surface acidity measurement were performed. Results indicated that the increasing surface acidity and the high specific surface area of the material were the relevant physicochemical properties that facilitate environment-friendly citronellal cyclization. The higher values for both parameters in Zn/PCH than in Zn/PILS linearly affected citronellal conversion and the selectivity for isopulegol production. Zn/PCH demonstrated a conversion rate of 98.9% for a 3-hour reaction and a selectivity of 100% for isopulegol production, and it exhibited reusability properties.

Nucleation and Atmospheric Aerosols, 2020

Nucleation and Atmospheric Aerosols, 2022

Green capping agent and green sensitizer of TiO 2 for photocatalytic activity: Mini review

Applied Clay Science, Aug 1, 2020

Nanocomposites of tin oxide immobilized in montmorillonite (Mt) with various Sn/Mt. mole-to-mass ... more Nanocomposites of tin oxide immobilized in montmorillonite (Mt) with various Sn/Mt. mole-to-mass ratios were prepared for photocatalysis application. The prepared samples were characterized by x-ray diffraction, transmission electron microscopy, N 2 adsorption-desorption analysis, and diffuse reflectance UV-visible spectroscopy. The relationships between the physicochemical characteristics and photocatalytic activities of the materials were evaluated in terms of rhodamine B photocatalytic degradation. From the results, the samples showed that the Sn/ Mt. mole-to-mass ratio affects the increase in the interlayer space of the montmorillonite structure, and the particle size of the dispersed SnO 2 nanoparticles increases with increasing ratio, ranging from 10 to 50 nm. The BET specific surface area, pore volume, and band gap energy of the nanocomposites are related with the structural changes, which are closely related with the SnO 2 content. The materials exhibit excellent photocatalytic activity as indicated by their higher turnover number and degradation efficiency than those of SnO 2 and related photocatalysts. Statistical optimization of the effect of the physicochemical characteristics of the photocatalyst on photocatalytic activity by using the logit model revealed that SnO 2 and pH affect the degradation efficiency and initial rate of rhodamine B degradation.

Sustainable Chemistry and Pharmacy, Mar 1, 2019

Citral and citronellal are important chemicals in the pharmaceutical and chemical industries, sin... more Citral and citronellal are important chemicals in the pharmaceutical and chemical industries, since they can be converted into other more valuable chemicals that are needed in many pathways. From the perspective of green catalysis, the present investigation examines the preparation of a recyclable heterogeneous catalyst of ruthenium-supported saponite clay for microwave assisted catalytic hydrogen transfer. Catalysts were prepared by supporting ruthenium bipyridine cations within saponite interlayers at various ruthenium contents, and the catalysts were then characterized by x-ray diffraction (XRD), gas sorption measurements, and scanning electron microscopy-energy dispersive x-ray spectrometry (SEMEDX) analyses. The catalytic activity was determined using microwave-assisted conversion of citral and citronellal. The prepared catalysts exhibited significant activity in the microwave-assisted catalytic hydrogen transfer of citral and citronellal. The catalytic activity was related to the content of the supported ruthenium in the catalysts, which also contributed to the increased specific surface area and external surface area of the materials.

Open Chemistry, Sep 25, 2019

Andrographis paniculata Ness is one of the plants that is under explored and could contain potent... more Andrographis paniculata Ness is one of the plants that is under explored and could contain potentially active substances to serve as an antimalarial. Structure investigation of major compounds that have responsibility for the antimalarial activity of Andrographis paniculata Ness's n-hexane extract is very important so that it is known whether the antimalarial activity is synergistic or from the major compounds. Menthol and dioctyladipate as major component from n-hexane extract of Andrographis paniculata Ness have been succesfully isolated using simple and inexpensive methods. The solvent system used are n-hexane : ethyl acetate (10:1) and n-hexane: chloroform (10:3) consecutively either for column or preparative thin layer chromatography. FT-IR, 1 H-NMR and GC-MS were used to determine the structure of compounds. The activity of n-hexane extract, menthol and dioctyladipate related to the inhibition of heme polymerization have been done comprehensively. The inhibition of heme polymerization activity of isolate compounds and n-hexane extract are classified to a good level (dioctyl adipate IC 50 = 1.15 ± 0.41 mg/mL, menthol IC 50 = 0.31 ± 0,01 mg/mL, and n-hexane extract IC 50 = 0.07 ± 0.03 mg/mL) and potentially as antimalarial. From the IC 50 , the antimalarial activity of Andrographis paniculata Ness's n-hexane extract is working synergistically, not by the major compounds.

Universitas Islam Indonesia eBooks, Jul 10, 2017

Telah dilakukan reaksi tandem hidrogenasi-siklisasi menuju menthol dari citronellal secara satu t... more Telah dilakukan reaksi tandem hidrogenasi-siklisasi menuju menthol dari citronellal secara satu tahap dengan variasi metode berkatalis ZrO2 montmorillonite (Zr-MMT). Tujuan penelitian adalah untuk menentukan keefektifan katalis Zr-MMTdengan dua metode: metode dengan sistem flow terhadap campuran sitronellal-katalis setelah refluks dengan tekanan H2 sebesar 3 kPa dan metode yang lain sistem flow terhadap campuran sitronellal- katalis pada 200oC dengan tekanan H2 2kPa. Hasil reaksi dianalisis menggunakan GC-MS dengan menentukan total konversi dan rendemen mentol. Hasil menunjukkan bahwa metode yang berbeda memberikan mekanisme reaksi yang signifikan. Metode pertama memberikan konversi sebesar 99% dengan produk utama isomenthon dan isopulegol sedangkan metode ke dua memberikan nilai konversi 5,18% dengan selektifitas sebesar 0,39% terhadap menthol. Dibandingkan dengan montmorillonit alam, kedua proses memberikan nilai konversi lebih besar dimana konversi menggunakan ...

Minyak atsiri merupakan jenis minyak yang diperoleh dari tanaman. Untuk membedakan minyak atsiri ... more Minyak atsiri merupakan jenis minyak yang diperoleh dari tanaman. Untuk membedakan minyak atsiri dengan jenis minyak nabati ada beberapa sifat yang harus diperhatikan. Minyak atsiri memiliki bau yang khas sesuai jenis tanamannya; ada yang harum lembut, ada yang menyengat bahkan bau tidak enak bagi yang sensitif penciumannya. Jadi bila dihadapkan pada kita dua jenis minyak dari tumbuhan, cukup mudah membedakan mana yang minyak atsiri dan mana yang minyak nabati, yaitu dari baunya. Hampir semua minyak nabati tidak berbau, kecuali yang terdegradasi atau rusak (rancid). Minyak nabati merupakan istilah khusus untuk minyak dari tanaman yang mengandung trigliserida. sementara minyak atsiri merupakan salah satu jenis bahan yang berbentuk minyak yang tersusun oleh campuran senyawa organik yang sebagian besar digolongkan ke dalam senyawa terpenoid.
Senyawa ini dicirikan oleh adanya ikatan lima karbon yang membentuk kerangka isoprenoid. Kerangka isoprenoid dapat berupa ikatan jenuh (isopentana) atau ikatan tak jenuh (isopentena). Dalam susunannya, kerangka isoprenoid dapat membentuk kelompok terpenoid yang berbeda yaitu monoterpen (10 karbon), seskuiterpen (15 karbon), diterpen (20 karbon), triterpen (30 karbon) dan tetraterpen (40 karbon).

Nucleation and Atmospheric Aerosols, 2021

This work studied the use of chitosan-based edible coatings enriched with essential oils to impro... more This work studied the use of chitosan-based edible coatings enriched with essential oils to improve storability of strawberries. It was started by analysis of the essential oil (Lemongrass oil and Basil oil) by gas chromatography-mass spectrometry. The main constituent of those essential oils was citral, as an antifungal activity. The edible coatings based on chitosan (CT), chitosan-lemongrass oil (CT-LO), and chitosan-basil oil (CT-BO). Thus, in this work CT, CT-LO, and CT-BO were elaborated and applied to fresh strawberries, and its effect on the strawberries shelf life during storage for 15 days was evaluated by fungal decay. The concentrations of essential oils were 0.25%, 0.5%, 0.75%, 1%, 1.25%. The edible coatings have been shown to prolong the storage life of strawberries

INDONESIAN JOURNAL OF CHEMICAL RESEARCH, 2020

Isolasi dan identifikasi sifat fisika-kimia minyak atsiri bunga kenanga (Cananga odorata) segar d... more Isolasi dan identifikasi sifat fisika-kimia minyak atsiri bunga kenanga (Cananga odorata) segar dan layu telah dilakukan dalam penelitian ini. Minyak atsiri bunga kenanga diisolasi dengan metode destilasi uap. Komponen kimia dari dua kondisi bahan bunga kenanga dianalisis menggunakan instrumen GCMS. Beberapa parameter fisika meliputi uji warna, bau, berat jenis dan indeks bias dilakukan dalam penelitian ini. Hasil analisis diketahui rendemen minyak atsiri pada bunga kenanga segar dan layu masing-masing adalah 0,325%(b/b) dan 0,276%(b/b). Komponen senyawa kimia utama yaitu 1-metoksi-4-metil benzena (3,05%) linalool (22,06%), geranil asetat (7,54%), trans-kariofilen (28,06%),a-humulen (8,65%) dan D-germacren (21,91%), sedangkan penyusun minyak kenanga layu adalah 1-metoksi-4-metil benzena (2,79%), linalool (21,76%), trans-kariofilen (31,87%), a-humulen (9,25%) dan D-germacren (21,62%). Hasil uji sifat fisika-kimia minyak bunga kenanga segar berwarna kuning bening, bau harum kenanga, b...

Indonesian journal of essential oil, Nov 1, 2016

Telah dilakukan penelitian secara eksperimen laboratorium tentang isolasi sitral yang merupakan k... more Telah dilakukan penelitian secara eksperimen laboratorium tentang isolasi sitral yang merupakan komponen terbesar dari minyak kemangi (Ocimum citriodorum, L). Minyak kemangi dapat diisolasi dari tanaman kemangi dengan penyulingan uap (steam distillation). Rendemen minyak kemangi hasil penyulingan sebesar 0,2 % b/b. Hasil kromatogram minyak kemangi (Ocimum citriodorum, L) menunjukkan konsentrasi sitral sebesar 33,82% dengan komposisi cis-sitral sebesar 14,86% dan trans-sitral sebesar 18,96%. Dalam penelitian ini sitral dalam minyak kemangi diisolasi dengan dua metode yaitu metode ekstraksi bisulfit dan metode distilasi uap. Isolasi sitral dengan metode ekstraksi bisulfit dilakukan secara kimia dengan mereaksikannya dengan larutan jenuh Natrium Bisulfit (NaHCO3) sementara isolasi sitral dengan metode distilasi uap dilakukan dengan rangkaian alat gelas kimia skala 500 mL. Isolasi sitral dengan metode distilasi uap dilakukan dengan perbandingan minyak kemangi dan air

3rd INTERNATIONAL SEMINAR ON SCIENCE AND TECHNOLOGY (ISSTEC) 2021: Science, Technology and Data Analysis for Sustainable Future

IJCR : Indonesian Journal of Cemical Research, Jun 2, 2018

Chemical engineering transactions, Mar 20, 2017

Slow release fertiliser (SRF) is one of the important materials, which provides benefit to the gr... more Slow release fertiliser (SRF) is one of the important materials, which provides benefit to the green chemistry and green chemical engineering in the agricultural applications. Various modifications on porous materials and super-adsorbent based composites have been developed to act as the host for fertilisers including nitrogenbased fertilisers. In this work, a scheme of organic nitrogen compound, methenamine, was used as the SRF compound and in order to increase the effectivity of the releasing nitrogen, immobilisation of the compound in montmorillonite clays has been conducted. Methenamine immobilised montmorillonite at varied methenamine contents (20 mmol/g; 50 mmol/g and 100 mmol/g) was prepared using intercalation process by employing microwave irradiation method. Study on the change of crystallinity and chemical structure of the composite was performed by x-ray diffraction (XRD) analysis, gas sorption analyser, and electronic microscope analysis. The kinetic study of the nitrogen release was conducted by FTIR and HPLC methods. Results showed that physicochemical character of the composite is affected by the methenamine content and the pH of the solution gives influence on the methenamine desorption from the composite.

Nucleation and Atmospheric Aerosols, 2022

Green capping agent and green sensitizer of TiO 2 for photocatalytic activity: Mini review

Jurnal Penelitian Saintek, 2013

Telah dilakukan reaksi tandem hidrogenasi-siklisasi menuju menthol dari citronellal secara satu t... more Telah dilakukan reaksi tandem hidrogenasi-siklisasi menuju menthol dari citronellal secara satu tahap dengan variasi metode berkatalis ZrO 2 montmorillonite (Zr-MMT). Tujuan penelitian adalah untuk menentukan keefektifan katalis Zr-MMTT dengan dua metode: metode dengan sistem flow terhadap campuran sitronellal-katalis setelah refluks dengan tekanan H 2 sebesar 3 kPa dan metode yang lain sistem flow terhadap campuran sitronellalkatalis pada 200 o C dengan tekanan H 2 2kPa. Hasil reaksi dianalisis menggunakan GC-MS dengan menentukan total konversi dan rendemen mentol. Hasil menunjukkan bahwa metode yang berbeda memberikan mekanisme reaksi yang signifikan. Metode pertama memberikan konversi sebesar 99% dengan produk utama isomenthon dan isopulegol sedangkan metode ke dua memberikan nilai konversi 5,18% dengan selektifitas sebesar 0,39% terhadap menthol. Dibandingkan dengan montmorillonit alam, kedua proses memberikan nilai konversi lebih besar dimana konversi menggunakan montmorillonit kurang dari 5%. Ketercukupan laju H 2 sebagai reaktan adalah faktor penting dalam menentukan mekanisme.

Nucleation and Atmospheric Aerosols, 2018

There are several challenges arose in the conduct of subjects which are supported with the labora... more There are several challenges arose in the conduct of subjects which are supported with the laboratory (lab) works as it was found in the course of Chromatography in the Study Program of Chemistry, Universitas Islam Indonesia. Firstly, the theoretical aspects in this course which are delivered in the class lecture were considered very broad and including various types of chromatography, in which not all of these could be applied for the lab work materials. Secondly, the chromatography lab work was conducted in the same semester with the course and the lab work series which was usually finished earlier than the class lecture. Lastly, the greatest difficulty faced by the students when they obtained data from the lab activities and they had to perform interpretation and analysis based on the results of the chromatography analysis to be written into the final lab report. Therefore in order to solve these problems, a new method containing learning activities in class which was designed in this research to synchronize the chromatographic course and the lab work was applied. The activity designed for the synchronization process in this research involved the application of problem based learning (PBL) method based on learning scenarios. Students were guided to extract some problems from the experiment performed in the lab especially those related to the analysis and interpretation of the data resulted followed by group discussion. After completing the task, on each schedule of class activity material related to the lab work material, some of the groups who had obtained the related topic in the lab work explained the problems they dealt with as well as the solutions they obtained to interpret the results of their analysis. At the end of the class activity, lecturer confirmed what the presenters in each group were delivered. Afterwards, the lecturer should explain the chromatographic material in accordance with the course outline.There are several challenges arose in the conduct of subjects which are supported with the laboratory (lab) works as it was found in the course of Chromatography in the Study Program of Chemistry, Universitas Islam Indonesia. Firstly, the theoretical aspects in this course which are delivered in the class lecture were considered very broad and including various types of chromatography, in which not all of these could be applied for the lab work materials. Secondly, the chromatography lab work was conducted in the same semester with the course and the lab work series which was usually finished earlier than the class lecture. Lastly, the greatest difficulty faced by the students when they obtained data from the lab activities and they had to perform interpretation and analysis based on the results of the chromatography analysis to be written into the final lab report. Therefore in order to solve these problems, a new method containing learning activities in class which was designed in this research to synch...

Bulletin of Chemical Reaction Engineering & Catalysis, Nov 13, 2019

Green conversion in organic synthesis is one of the interesting and important topics in green che... more Green conversion in organic synthesis is one of the interesting and important topics in green chemistry. The use of heterogeneous catalysis instead of homogeneous catalysis offers some advantages, such as easy separation and reusability. In this research, a heterogeneous acid catalyst was prepared from saponite by immobilizing ZnO in the form of a pillared clay (Zn/PILS) and Zn supported on porous clay heterostructure (Zn/PCH). Physicochemical studies involving X-ray diffraction measurement, surface analysis using a gas sorption analyzer, and surface acidity measurement were performed. Results indicated that the increasing surface acidity and the high specific surface area of the material were the relevant physicochemical properties that facilitate environment-friendly citronellal cyclization. The higher values for both parameters in Zn/PCH than in Zn/PILS linearly affected citronellal conversion and the selectivity for isopulegol production. Zn/PCH demonstrated a conversion rate of 98.9% for a 3-hour reaction and a selectivity of 100% for isopulegol production, and it exhibited reusability properties.

Nucleation and Atmospheric Aerosols, 2020

Nucleation and Atmospheric Aerosols, 2022

Green capping agent and green sensitizer of TiO 2 for photocatalytic activity: Mini review

Applied Clay Science, Aug 1, 2020

Nanocomposites of tin oxide immobilized in montmorillonite (Mt) with various Sn/Mt. mole-to-mass ... more Nanocomposites of tin oxide immobilized in montmorillonite (Mt) with various Sn/Mt. mole-to-mass ratios were prepared for photocatalysis application. The prepared samples were characterized by x-ray diffraction, transmission electron microscopy, N 2 adsorption-desorption analysis, and diffuse reflectance UV-visible spectroscopy. The relationships between the physicochemical characteristics and photocatalytic activities of the materials were evaluated in terms of rhodamine B photocatalytic degradation. From the results, the samples showed that the Sn/ Mt. mole-to-mass ratio affects the increase in the interlayer space of the montmorillonite structure, and the particle size of the dispersed SnO 2 nanoparticles increases with increasing ratio, ranging from 10 to 50 nm. The BET specific surface area, pore volume, and band gap energy of the nanocomposites are related with the structural changes, which are closely related with the SnO 2 content. The materials exhibit excellent photocatalytic activity as indicated by their higher turnover number and degradation efficiency than those of SnO 2 and related photocatalysts. Statistical optimization of the effect of the physicochemical characteristics of the photocatalyst on photocatalytic activity by using the logit model revealed that SnO 2 and pH affect the degradation efficiency and initial rate of rhodamine B degradation.

Sustainable Chemistry and Pharmacy, Mar 1, 2019

Citral and citronellal are important chemicals in the pharmaceutical and chemical industries, sin... more Citral and citronellal are important chemicals in the pharmaceutical and chemical industries, since they can be converted into other more valuable chemicals that are needed in many pathways. From the perspective of green catalysis, the present investigation examines the preparation of a recyclable heterogeneous catalyst of ruthenium-supported saponite clay for microwave assisted catalytic hydrogen transfer. Catalysts were prepared by supporting ruthenium bipyridine cations within saponite interlayers at various ruthenium contents, and the catalysts were then characterized by x-ray diffraction (XRD), gas sorption measurements, and scanning electron microscopy-energy dispersive x-ray spectrometry (SEMEDX) analyses. The catalytic activity was determined using microwave-assisted conversion of citral and citronellal. The prepared catalysts exhibited significant activity in the microwave-assisted catalytic hydrogen transfer of citral and citronellal. The catalytic activity was related to the content of the supported ruthenium in the catalysts, which also contributed to the increased specific surface area and external surface area of the materials.

Open Chemistry, Sep 25, 2019

Andrographis paniculata Ness is one of the plants that is under explored and could contain potent... more Andrographis paniculata Ness is one of the plants that is under explored and could contain potentially active substances to serve as an antimalarial. Structure investigation of major compounds that have responsibility for the antimalarial activity of Andrographis paniculata Ness's n-hexane extract is very important so that it is known whether the antimalarial activity is synergistic or from the major compounds. Menthol and dioctyladipate as major component from n-hexane extract of Andrographis paniculata Ness have been succesfully isolated using simple and inexpensive methods. The solvent system used are n-hexane : ethyl acetate (10:1) and n-hexane: chloroform (10:3) consecutively either for column or preparative thin layer chromatography. FT-IR, 1 H-NMR and GC-MS were used to determine the structure of compounds. The activity of n-hexane extract, menthol and dioctyladipate related to the inhibition of heme polymerization have been done comprehensively. The inhibition of heme polymerization activity of isolate compounds and n-hexane extract are classified to a good level (dioctyl adipate IC 50 = 1.15 ± 0.41 mg/mL, menthol IC 50 = 0.31 ± 0,01 mg/mL, and n-hexane extract IC 50 = 0.07 ± 0.03 mg/mL) and potentially as antimalarial. From the IC 50 , the antimalarial activity of Andrographis paniculata Ness's n-hexane extract is working synergistically, not by the major compounds.

Universitas Islam Indonesia eBooks, Jul 10, 2017

Telah dilakukan reaksi tandem hidrogenasi-siklisasi menuju menthol dari citronellal secara satu t... more Telah dilakukan reaksi tandem hidrogenasi-siklisasi menuju menthol dari citronellal secara satu tahap dengan variasi metode berkatalis ZrO2 montmorillonite (Zr-MMT). Tujuan penelitian adalah untuk menentukan keefektifan katalis Zr-MMTdengan dua metode: metode dengan sistem flow terhadap campuran sitronellal-katalis setelah refluks dengan tekanan H2 sebesar 3 kPa dan metode yang lain sistem flow terhadap campuran sitronellal- katalis pada 200oC dengan tekanan H2 2kPa. Hasil reaksi dianalisis menggunakan GC-MS dengan menentukan total konversi dan rendemen mentol. Hasil menunjukkan bahwa metode yang berbeda memberikan mekanisme reaksi yang signifikan. Metode pertama memberikan konversi sebesar 99% dengan produk utama isomenthon dan isopulegol sedangkan metode ke dua memberikan nilai konversi 5,18% dengan selektifitas sebesar 0,39% terhadap menthol. Dibandingkan dengan montmorillonit alam, kedua proses memberikan nilai konversi lebih besar dimana konversi menggunakan ...

AIP Conference Proceedings, 2020