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All Journal Jurnal Riset Kimia Sains Natural: Journal of Biology and Chemistry Chemistry Indonesian Journal of Chemical Research Journal Of Research and Education Chemistry (JREC) Makara Journal of Science Indonesian Journal of Chemical Engineering
Lee Wah Lim
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Agriculture, Biological Sciences & Forestry Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Chemistry Education Engineering Environmental Science Materials Science & Nanotechnology

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OPTIMATION STUDY OF CARRAGEENAN EXTRACTION FROM RED ALGAE (Eucheuma cottonii) -, Refilda; Munaf, Edison; Zein, Rahmiana; Dharma, Abdi; -, Indrawati; Lim, Lee Wah; Takeuchi, Toyohide
Jurnal Riset Kimia Vol 2, No 2 (2009): March
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v2i2.151

Abstract

 ABSTRACT Carrageenan is a general name for polysacharides, it is made up of sodium, potassium, magnesium, and calcium sulphat esters of galactose and 3.6-anhydrogalactose units. Research about parameters influencing extraction process of carrageenan from red algae (Eucheuma cottonii) has been studied. The parameters were particle size of red algae, pH of NaOH solution, heating time and heating temperature. About 64.30% of carrageenan was extracted from red algae (Eucheuma cottonii) under optimum condition, 425 µm particle size of red algae, solution pH 8.5, heating time 18 h, and heating temperature 95°C. The FTIR spectra of extracted carrageenan showed the same spectra as the pure carrageenan. Keywords : carrageenan, red algae (Eucheuma cottonii), and extraction    
DETERMINATION OF CYCLODEXTRINS BY CAPILLARY LIQUID CHROMATOGRAPHY WITH INDIRECT CONDUCTIMETRIC DETECTION Toyohide Takeuchi; Anang Sedyohutomo; Lee Wah Lim
Jurnal Riset Kimia Vol. 4 No. 1 (2010): September
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v4i1.112

Abstract

   ABSTRACT Cyclodextrins (CDs) contained in a bottled Japanese tea and a wasabi (Japanese horseradish) paste were determined by capillary liquid chromatography (LC) with indirect conductimetric detection based on dilution of the mobile phase due to the analytes. High electrical conductivity background was maintained by addition of 5 mM sodium nitrate in the mobile phase, and the analytes were visualized by decreases in the background when they eluted. The dynamic reserve, defined as the ratio of the background to its noise level, achieved under the present conditions was 1.7×105, which was much larger than that achieved by UV absorption detection. This means that indirect conductimetric detection gave better sensitivity than indirect UV absorption detection. A capacitively coupled contactless conductivity detector was convenient to monitor the effluents from capillary columns with minimum extra-column band broadening. The signals as negative peaks were linear to the concentration of the analytes, and the concentration detection limits achieved at S/N=3 were 0.02, 0.05 and 0.02% (w/v) for α-, β- and γ-CD, respectively, corresponding to the mass detection limits of 30-75 ng for 0.15 μL injection. The present detection method is not selective but universal, and it is useful in capillary LC when analytes have neither chromophore nor fluorophore groups. Keywords: Capillary liquid chromatography, Indirect conductimetric detection, Capacitively coupled contactless conductivity detector, Cyclodextrins
OPTIMATION STUDY OF CARRAGEENAN EXTRACTION FROM RED ALGAE (Eucheuma cottonii) Refilda -; Edison Munaf; Rahmiana Zein; Abdi Dharma; Indrawati -; Lee Wah Lim; Toyohide Takeuchi
Jurnal Riset Kimia Vol. 2 No. 2 (2009): March
Publisher : Universitas Andalas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25077/jrk.v2i2.151

Abstract

 ABSTRACT Carrageenan is a general name for polysacharides, it is made up of sodium, potassium, magnesium, and calcium sulphat esters of galactose and 3.6-anhydrogalactose units. Research about parameters influencing extraction process of carrageenan from red algae (Eucheuma cottonii) has been studied. The parameters were particle size of red algae, pH of NaOH solution, heating time and heating temperature. About 64.30% of carrageenan was extracted from red algae (Eucheuma cottonii) under optimum condition, 425 µm particle size of red algae, solution pH 8.5, heating time 18 h, and heating temperature 95°C. The FTIR spectra of extracted carrageenan showed the same spectra as the pure carrageenan. Keywords : carrageenan, red algae (Eucheuma cottonii), and extraction    
Determination of Polycyclic Aromatic Hydrocarbons (PAHs) Using Environmentally Friendly Liquid Chromatography Kurnia, Asep; Lim, Lee Wah; Takeuchi, Toyohide
Makara Journal of Science Vol. 22, No. 1
Publisher : UI Scholars Hub

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Abstract

An analytical methodto determine polycyclic aromatic hydrocarbons (PAHs) is required to obtain high-quality analytical results. The purpose of this study is to achievegood separation ofa few PAHs by using environmentally friendly liquid chromatography. Accordingly, a liquid chromatograph incorporating a fluorescence detector, UV detector, and a capillary column is employed herein to simultaneously minimize the use of chemicals and obtain analytical results better than those obtained using aconventional column. Observation parameter include single analysis ofeach PAH, method valida-tion, the new stationary phase, the effectof mobile phase concentration, and Quenchereffect. The PAHs tested include naphthalene, phenanthrene, anthracene, fluoranthene, and pyrene. The test results show that when using an acetonitrile concentration of 100%, the retention times of different PAHs do not differ significantly. Furthermore, upon decreasing the acetonitrile concentration, the retention time increases, and better separation was achieved. The value ranges of precision, LOD, LOQ, and linearity are 3.43 – 12.42%, 4.7–15.1 mg/L, 15.6 – 50.5 mg/L, and 0.87–0.99, respectively. The new Sil-S-ImC30 stationary phase showed good results in terms of separation of PAHs. Likewise, the use of 60, 70, 80, and 90% acetonitrile as the mobile phase in combination with 0.03 M acrylamide as the quencher affected retention time but not separation.
Determination of Carbofuran on Hydrophilic Interaction Liquid Chromatography using TSKgel®Amide-80 as a Stationary Phase Kurnia, Asep; Lim, Lee Wah; Takeuchi, Toyohide
Makara Journal of Science Vol. 20, No. 4
Publisher : UI Scholars Hub

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Abstract

Hydrophilic interaction liquid chromatography (HILIC) equipped with an environmentally friendly capillary column was employed to investigate the retention behavior of carbofuran; a polar stationary phase was used as well. Several conditions were conducted to investigate the retention behavior of carbofuran, such as a comparison study TSKgel®Amide-80 with another polar column, a comparison study retention behavior of carbofuran on various wavelengths, the water content effect on HILIC mode, the effect of buffer concentration on HILIC mode, and the analytical performance of carbofuran. The results showed that TSKgel®Amide-80 exhibited a better performance than other polar stationary phases in carbofuran determination, and observations at wavelengths of 251 and 254 nm showed higher absorbance for carbofuran than others. In addition, the increase of water content and salt buffer concentration in the mobile phase led to a shorter retention time. The recovery of this method was 101 ± 10.1%, while the limit of detection and the limit of quantification were 0.66 ppm and 2.22 ppm, respectively. Consequently, TSKgel®Amide-80 offers a good perform
The Multi Soil layering Method for Wastewater Treatment: Review Rahayu, Aster; Mulyadi, Irwan; Fajri, Joni Aldilla; Jamilatun, Siti Jamilatun; Nuraini, Nuraini; Wulandari, Nurul; Marlena, Yuni; Ningsih, Devi Yogi Noviana; Lim, Lee Wah
Indonesian Journal of Chemical Research Vol 10 No 2 (2022): Edition for September 2022
Publisher : Jurusan Kimia, Fakultas Sains dan Teknologi, Universitas Pattimura

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30598//ijcr.2022.10-ast

Abstract

Liquid waste is the main source of contamination of water bodies, especially river water. This pollution causes decreased water quality in water bodies. One of the wastewater treatment treatments is the Multi Soil Layering (MSL) method. Some of the advantages of using the MSL method are that it is known to be cheap in terms of cost, easy to implement, does not require complicated maintenance so that it can be used continuously, and is also environmentally friendly. One of the constituent materials of the MSL reactor is andesol soil, gravel, and pearlite. MSL has two wastewater treatment zones, the aerobic zone, and the anaerobic zone. The article review aims to compare the efficiency of reducing the levels of pollutant parameters from aerobic and anaerobic processes in MSLmethod in wastewater.
Isotherm Adsorption of Ion Phosphate from Vinasse Waste Using Quaternary Ammonium Polymer as Adsorbent in Term Effect of Temperature Veranica; Rahayu, Aster; Maryudi; Dhias Cahya Hakika; Lee Wah Lim; Lia Anggresani
Sains Natural: Journal of Biology and Chemistry Vol. 14 No. 2 (2024): Sains Natural
Publisher : Universitas Nusa Bangsa

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31938/jsn.v14i2.720

Abstract

Vinasse liquid waste is a waste product resulting from the ethanol distillation process. Phosphate in high concentrations can harm the environment, such as by polluting water sources and underground surfaces. In this research, adsorption of phosphate ions was carried out in vinasse waste to remove these pollutants using quaternary ammonium polymers. The study examined the effect of vinasse waste sample temperature on the adsorption of phosphate ions. The first step in this work was to create a quaternary ammonium polymer utilising a one-pot technique using 2-[methacryloyloxy)ethyl trimethylammonium chloride solution, also referred to as META. Subsequently, the adsorption process was performed using temperature variations of 25, 30, 40, 50, and 60 . Phosphate ion adsorbance was measured with UV-Vis spectrometers at a wavelength of 880 nm. The quaternary ammonium polymer succeeded in adsorbing the phosphate ion content of the vinasse waste at an optimal temperature of 40 , with an adsorption capacity of 3.78 mg/L and a removal efficiency of 75.70%.  The adsorption isotherm model for phosphate ions onto quaternary ammonium polymer was studied using the Freundlich and Langmuir equations. The obtained data indicated that the Langmuir isotherm model, with an value of 0.9921, is well-suited for describing the adsorption behaviour in this research.
Isothermic Adsorption Study of Nitrate Ion Adsorption in Bioethanol Waste Using Quaternary Ammonium Polymer Amrillah, Nafira Alfi Zaini; Rahayu, Aster; Dhias Cahya Hakika; Vivi Sisca; Veranica; Firda Mahira Alfiata Chusna; Lia Anggresani; Lee Wah Lim
Sains Natural: Journal of Biology and Chemistry Vol. 15 No. 1 (2025): Sains Natural
Publisher : Universitas Nusa Bangsa

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31938/jsn.v15i1.770

Abstract

The global shift towards renewable energy sources has led to a significant increase in bioethanol production, particularly from sugar mills. Despite being an environmentally friendly alternative to fossil fuels, bioethanol production produces large amounts of waste containing dangerous contaminants such as nitrate ions (NO₃⁻). These contaminants pose severe environmental and health risks, including water pollution and eutrophication. This study explores the use of ammonium polymer as an adsorbent and the influence of pH in the adsorption process as a promising technique for removing nitrate ions from bioethanol waste. Based on the analysis that has been carried out, the optimal pH for adsorption of nitrate ions is around 9, where the removal efficiency (%RE) reaches 98.43% and the adsorption capacity (Qe) is 24.86 mg/g. These experiments show that the Freundlich model, with a heterogeneity factor (n) of 1.0947 and a Freundlich constant (KF) of 1.92 x 10³ units, provides the best fit to the adsorption data, indicating a heterogeneous adsorption process with a strong affinity for nitrate ions.
Utilizing Anadara granosa Shells and PVA for Porous Hydroxyapatite Synthesis Anggresani, Lia; Nurmelinda, Nurmelinda; Yulianis, Yulianis; Lee Wah Lim
Indonesian Journal of Chemical Engineering Vol. 1 No. 2 (2023)
Publisher : Universitas Ahmad Dahlan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26555/ijce.v1i2.663

Abstract

The majority of the inorganic material that makes up teeth and bones is called hydroxyapatite (Ca10(PO4)6(OH)2), and it is produced by isolating calcium oxide (CaO) from the high calcium carbonate content of anadara granosa shells, which is over 98%. The porous HAp is the type of hydroxyapatite that can be used for bone repair. The aim of this work is to use the polymer polyvinyl alcohol to synthesis porous hydroxyapatite from anadara granosa shell. The anadara granosa powder (AGP) was furnaced for 3 hour at 800oC. CaO powder was produced. Then, the CaO powder was treated with (NH4)2HPO4 at a mol Ca/P 1.67 to obtained the HAp. Then, HAp is combined with a PVA polymer at a 10:1 ratio. Compressive strength tests, FTIR, SEM, and XRD are carried out. The compressive strength resulted for HAp and porous HAp were14.58 and 50.43 Mpa., respectively. The results indicated that PVA achieved a good compressive strength with Hydroxyapatite – Anadara granosa shell.
Pengaruh Suhu dalam Pembuatan Fasa Diam Silika Hibrid Monolit sebagai Studi Awal untuk Kromatografi Cair Sistem Kapiler Furqani, Firda; Bella, Ilona; Hillman, Prima Fitria; Lim, Lee Wah
Journal of Research and Education Chemistry Vol. 7 No. 2 (2025): Oktober
Publisher : UIR Press

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.25299/jrec.2025.vol7(2).25260

Abstract

Penelitian ini merupakan studi awal mengenai pembuatan dan karakterisasi fasa diam silika hibrid monolit untuk aplikasi pada kromatografi cair sistem kapiler. Material monolit disintesis melalui metode sol-gel dengan menggunakan trimetoksipropilsilana (TPMS) dan (3-glisidoksipropil)trimetoksisilan (GPTMS) sebagai prekursor silika, yang dimodifikasi dengan asam amino sebagai monomer organik untuk memperkenalkan gugus fungsional aktif pada permukaan. Struktur dan morfologi monolit yang dihasilkan diamati menggunakan mikroskop elektron pemindai (SEM), sedangkan stabilitas mekaniknya dievaluasi melalui pengukuran penurunan tekanan (pressure drop) pada sistem aliran. Uji performa kromatografi dilakukan untuk menilai kemampuan kolom monolit dalam memisahkan dua analit model, yaitu urasil (senyawa polar) dan toluena (senyawa nonpolar). Hasil penelitian menunjukkan bahwa monolit yang disintesis memiliki morfologi berpori homogen dengan adhesi kuat pada dinding kapiler, serta menunjukkan stabilitas mekanik yang baik terhadap tekanan aliran. Kemampuan pemisahan yang ditunjukkan menandakan potensi material silika hibrid monolit ini untuk dikembangkan lebih lanjut sebagai fasa diam pada sistem capillary liquid chromatography (CLC).
Co-Authors Abdi Dharma Amrillah, Nafira Alfi Zaini Anang Sedyohutomo Dhias Cahya Hakika Edison Munaf Edison Munaf Fajri, Joni Aldilla Firda Mahira Alfiata Chusna Furqani, Firda Hillman, Prima Fitria Ilona Bella Indrawati - Indrawati Indrawati Jamilatun, Siti Jamilatun Kurnia, Asep Lia Anggresani Marlena, Yuni Maryudi Mulyadi, Irwan Ningsih, Devi Yogi Noviana Nuraini Nuraini Nurmelinda, Nurmelinda NURUL WULANDARI Rahayu, Aster Rahmiana Zein Refilda Refilda Toyohide Takeuchi Veranica Vivi Sisca Yulianis Yulianis