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All Journal Indonesian Chimica Letters
Adiwinata, I Nyoman
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Chemistry

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Effect of Zeolite Concentration on Hydrogel Characteristics of Arrowroot-Based Starch-G-Poly(Acrylic Acid)/Zeolite Composite Sjaifullah, Achmad; Saputra, Beny Akhmat; Adiwinata, I Nyoman; Santoso, Agung Budi; Busroni; Reza, Muhammad
Indonesian Chimica Letters Vol. 1 No. 2 (2022)
Publisher : Department of Chemistry, Faculty of Mathematics and Natural Sciences, University of Jember

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (856.304 KB) | DOI: 10.19184/icl.v1i2.201

Abstract

This study aims to synthesize a hydrogel zeolite composite of arrowroot starch graft copolymerized with acrylic acid through a radical polymerization reaction in a water. Various scenarios were tested using different natural zeolite concentration to determine the impact on swelling/water absorption of the composite. The resulting product was a solid gel-the test results showed that the swelling increased as the ratio of starch to acrylic acid decreased. Increased starch concentrations generally lead to decreased water absorption (swelling capacity). Adding a zeolite improved swelling to some extent and the optimum zeolite concentration was 60%. The increased concentration of zeolite also hardened the hydrogel composite. The highest swelling in the hydrogel composite of starch-g-poly(acrylic acid)/zeolite 60% is 1056.25 g.g-1. FTIR analysis of functional groups was conducted to determine differences in the IR spectra of arrowroot starch, acrylic acid, hydrogels, zeolites, and composite hydrogel. Si-O signal appearing on the IR spectra of hydrogel composite with wave number 1030 cm-1 indicates that composite hydrogel with zeolite was synthesized
Analysis of Flavonoid Contents in Coffee Mistella (Dendrophthoe pentandra (L.) Miq.) Using Thin Layer Chromatography-Densitometry Techniques Saputri, Nora Dwi; Adiwinata, I Nyoman; Muflihah, Yeni Maulidah
Indonesian Chimica Letters Vol. 3 No. 1 (2024)
Publisher : Department of Chemistry, Faculty of Mathematics and Natural Sciences, University of Jember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.19184/icl.v3i1.941

Abstract

Flavonoids, a class of phenolic compounds widely distributed in plants, are present in the coffee mistletoe Dendrophthoe pentandra (L.) Miq. The extraction of flavonoids from Dendrophthoe pentandra (L.) Miq leaves involve the use of methanol as a solvent in maceration extraction methods. The presence of flavonoids was ascertained through color changes from green to yellow-green, yellow, and yellow-orange when subjected to AlCl3 5%, NaOH 10%, and Mg-HCl, respectively. Thin-layer chromatography using aluminum plates coated with silica gel F254 as the stationary phase and methanol-chloroform 4:1 (v/v) as the mobile phase was employed to separate the flavonoids. The method validation demonstrated strong linearity in the concentration range of 60-130 ppm for flavonoid standard solutions, with a correlation coefficient (r) of 0.998. The Limit of Detection (LOD) and Limit of Quantitation (LOQ) were determined to be 182.5 ng and 608.3 ng, respectively. Precision, expressed as Relative Standard Deviation (RSD), was found to be 5.1%, 2.8%, and 2.5% for concentrations of 80, 90, and 100 ppm, respectively. These RSD values were also less than 2/3 CV Horwitz, which were 5.5, 5.4, and 5.4. The method's accuracy was assessed through percent recovery values for each concentration (80, 90, and 100 ppm), which were found to be 102.46 ± 1.78%, 86.14 ± 1.74%, and 89.89 ± 1.44%. The flavonoid content in the dried coffee mistletoe powder was determined to be 1.404x10-2 ± 0.0007 mg per gram, with a water content of 8.7%.
Co-Authors Achmad Sjaifullah Agung Budi Santoso Busroni Muhammad Reza Saputra, Beny Akhmat Saputri, Nora Dwi Yeni Maulidah Muflihah