Fluorescence Studies of Associating Polymers in Water: Determination of the Chain end Aggregation Number and a Model for the Association Process

1995 ◽  
Vol 28 (4) ◽  
pp. 956-966 ◽  
Author(s):  
Ahmad Yekta ◽  
Bai Xu ◽  
Jean Duhamel ◽  
Hendra Adiwidjaja ◽  
Mitchell A. Winnik
Keyword(s):  
Aggregation Number ◽  
Water Determination ◽  
Fluorescence Studies ◽  
Associating Polymers

scholarly journals Interaction of rice (Oryza sativa) lectin with N-acetylglucosaminides. Fluorescence studies

1985 ◽  
Vol 229 (3) ◽  
pp. 687-692 ◽  
Author(s):  
F Tabary ◽  
J P Frénoy
Keyword(s):  
Oryza Sativa ◽  
Binding Sites ◽  
Wheat Germ ◽  
Equilibrium Dialysis ◽  
Blue Shift ◽  
Association Constants ◽  
Fluorescence Studies ◽  
Saccharide Binding ◽  
Binding Enthalpy

The interaction of lectin isolated from rice (Oryza sativa) embryos with N-acetylglucosaminides was studied by equilibrium dialysis and fluorescence. Equilibrium dialysis with 4-methylumbelliferyl-(GlcNac)2 showed that rice lectin (Mr 38000) contains four equivalent saccharide-binding sites. Addition of the N-acetylglucosaminides GlcNac, (GlcNac)2 and (GlcNac)3 enhanced the intrinsic fluorescence of rice lectin and this was accompanied by a 10nm blue-shift of its maximum fluorescence with (GlcNac)2 and (GlcNac)3. These changes in intensity allowed determination of the association constants, which increased with the number of saccharide units: at 20 degrees C, Ka = (1.3 +/- 0.1) X 10(3), (5.1 +/- 0.4) X 10(4) and (2.6 +/- 0.1) X 10(5) M−1 for GlcNac, (GlcNac)2 and (GlcNac)3 respectively. The binding enthalpy, delta H0, for the three glucosaminides were very low and ranged from −12.1 to −20.6 kJ X mol-1. The results are compared with those obtained with wheat-germ agglutinin, another GlcNac-specific gramineaous lectin.

scholarly journals Iron in Well Water: Case Study in Dulalowo and Heledulaa Districts

2020 ◽  
Vol 2 (2) ◽  
pp. 46-52
Author(s):  
Hendri Iyabu ◽  
Anita Muhammad ◽  
Jafar La Kilo ◽  
Akram La Kilo
Keyword(s):  
Water Samples ◽  
Iron Concentration ◽  
Well Water ◽  
Iron Level ◽  
Water Determination ◽  
Drinking Water Standard ◽  
Water Wells ◽  
Fe Content

This study aims to determine the iron content of water wells in Dulalowo and Heledulaa, Gorontalo City. Ten well water samples were taken randomly from five different wells in each district. Water samples at each well consist of top, middle, and bottom water. Determination of iron level using Atomic Absorption Spectrophotometer (AAS) at a wavelength of 248.33 nm. The results showed that the iron concentration of well water in Dulalowo was 0.030 (D1), 0.265 (D2), 0.224 (D3), 0.158 (D4), 0.149 ppm (D5). Meanwhile, iron levels in Heledulaa were 0.100 (H1), 0.039 (H2), 0.159 (H3), 0.198 (H4), and 0.235 ppm (H5). These results prove that the Fe content in the well water in the two districts is still fulfil the drinking water standard which is a maximum of 0.3 mg/L iron.

scholarly journals Penentuan Konsentrasi Efektif Ekstrak Tanaman Patikan Kebo (Euphorbia Hirta) Merah Dan Hijau Dalam Melarutkan Kalsium

2018 ◽  
Vol 6 (4) ◽  
pp. 208
Author(s):  
Hamdiana Hamdiana ◽  
Minarni Rama Jura ◽  
Ratman Ratman
Keyword(s):  
Calcium Phosphate ◽  
Kidney Stones ◽  
Laboratory Experiments ◽  
Effective Concentration ◽  
Distilled Water ◽  
Water Determination ◽  
Euphorbia Hirta ◽  
Flame Photometer

The use of traditional materials is one alternative for the treatment of kidney stones. One of them is utilizing a plant of patikan kebo (Euphorbia hirta). This study is conducted by using laboratory experiments and the extract of the plant of patikan kebo red and patikan kebo green to dissolve the calcium phosphate as a substitute for kidney stones. The extraction of samples is conducted by decoction. The aim of the study is to determine the effective concentration of the extracts of patikan kebo red and green to dissolve calcium and test the effectiveness of the extracts of patikan kebo to dissolve calcium compared to Batugin elixir and distilled water. Determination of the concentration of dissolved calcium in the extracts using a flame photometer. The results show that the extract of patikan kebo red with a concentration of 2.1% is effective in dissolve the calcium with a concentration of 5.2 ppm. The extract of patikan kebo green with a concentration of 27.4% is effective in dissolving the calcium with a concentration of 27.5 ppm. When compared with Batugin elixir and distilled water, Batugin elixir can only dissolve the calcium with concentration 15.3 ppm, while distilled water can only dissolve 3 ppm of the calcium.

Determination of Water in Molasses by Karl Fischer Method

1971 ◽  
Vol 54 (5) ◽  
pp. 1231-1235
Author(s):  
Boris Kviesitis
Keyword(s):  
Collaborative Study ◽  
Oven Method ◽  
Vacuum Oven ◽  
Water Determination ◽  
Cane Molasses ◽  
Karl Fischer ◽  
Karl Fischer Method ◽  
Fischer Method

Abstract Successful use of the method depends on several factors, one of which is the size of the sample because it affects the result of the titration. In this study, 2 sizes of cane molasses samples were tested and the results were compared with those from the vacuum oven method. The use of larger samples with or without the addition of surfactant increased the precision of the analysis. It is recommended that the Karl Fischer method for water determination in molasses and sugar sirups be subjected to collaborative study.

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