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All Journal Jurnal Riset Kimia Makara Journal of Science
Lee Wah Lim
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Chemistry

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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
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
Co-Authors Abdi Dharma Anang Sedyohutomo Edison Munaf Edison Munaf Indrawati - Indrawati Indrawati Kurnia, Asep Rahmiana Zein Refilda Refilda Toyohide Takeuchi