Polyelectrolyte titration using fluorescent indicator. I. Direct titration of anionic and cationic polyelectrolytes with 104N standard solutions

1993 ◽  
Vol 31 (11) ◽  
pp. 2687-2691 ◽  
Author(s):  
Hiroo Tanaka ◽  
Yumi Sakamoto
Keyword(s):  
Fluorescent Indicator ◽  
Direct Titration ◽  
Polyelectrolyte Titration ◽  
Cationic Polyelectrolytes ◽  
Standard Solutions

Direct Titrimetric Microdetermination of Fluorodifen, Linuron, Faneron, and Pebulate

1973 ◽  
Vol 56 (2) ◽  
pp. 387-389
Author(s):  
Syed L Abbas ◽  
Asoke K Ghosh ◽  
Saiyid A I Rizvi ◽  
Om C Saxena
Keyword(s):  
Chloride Solution ◽  
Gallium Chloride ◽  
Direct Titration ◽  
Standard Solutions

Abstract The herbicides fluorodifen, linuron, faneron, and pebulate have been determined in individual standard solutions by direct titration against gallium chloride solution, using different indicators. The same technique is applied to estimation of these herbicides in treated soils. The complex between gallium chloride and fluordifen or linuron is formed in a 1:3 ratio, whereas the complex with faneron or pebulate is in a 1:1 ratio. Recoveries for fluorodifen, linuron, faneron, and pebulate were 99.9–101.5, 99.0–102.4, 97.1–101.3, and 98.3–101.2%, respectively. Treatment with herbicide lowered the pH of the soil.

Effect of cationic polyelectrolytes in contact-active antibacterial layer-by-layer functionalization

Holzforschung ◽  
2017 ◽  
Vol 71 (7-8) ◽  
pp. 649-658 ◽  
Author(s):  
Chao Chen ◽  
Josefin Illergård ◽  
Lars Wågberg ◽  
Monica Ek
Keyword(s):  
Cellulose Fibers ◽  
Antibacterial Activities ◽  
Layer By Layer ◽  
Cellulosic Fibers ◽  
Dimethyl Ammonium ◽  
Charge Interaction ◽  
Modification Technique ◽  
Polyelectrolyte Titration ◽  
A Charge ◽  
Cationic Polyelectrolytes

AbstractContact-active surfaces have been created by means of the layer-by-layer (LbL) modification technique, which is based on previous observations that cellulose fibers treated with polyelectrolyte multilayers with polyvinylamine (PVAm) are perfectly protected against bacteria. Several different cationic polyelectrolytes were applied, including PVAm, two different poly(diallyl dimethyl ammonium chloride) polymers and two different poly(allylamine hydrochloride) polymers. The polyelectrolytes were self-organized in one or three layers on cellulosic fibers in combination with polyacrylic acid by the LbL method, and their antibacterial activities were evaluated. The modified cellulose fibers showed remarkable bacterial removal activities and inhibited bacterial growth. It was shown that the interaction between bacteria and modified fibers is not merely a charge interaction because a certain degree of bacterial cell deformation was observed on the modified fiber surfaces. Charge properties of the modified fibers were determined based on polyelectrolyte titration and zeta potential measurements, and a correlation between high charge density and antibacterial efficiency was observed for the PVAm and PDADMAC samples. It was demonstrated that it is possible to achieve antibacterial effects by the surface modification of cellulosic fibers via the LbL technique with different cationic polyelectrolytes.

Complex formation of modified chitosan and carboxymethyl cellulose and its effect on paper properties

TAPPI Journal ◽  
2009 ◽  
Vol 8 (6) ◽  
pp. 29-35 ◽  
Author(s):  
PEDRAM FATEHI ◽  
LIYING QIAN ◽  
RATTANA KITITERAKUN ◽  
THIRASAK RIRKSOMBOON ◽  
HUINING XIAO
Keyword(s):  
Carboxymethyl Cellulose ◽  
Polymer System ◽  
Layer By Layer ◽  
Paper Strength ◽  
Anionic Polymer ◽  
Paper Properties ◽  
Modified Chitosan ◽  
Layer By Layer Assembly ◽  
Polyelectrolyte Titration ◽  
Layer Assembly

The application of an oppositely charged dual polymer system is a promising approach to enhance paper strength. In this work, modified chitosan (MCN), a cationic polymer, and carboxymethyl cellulose (CMC), an anionic polymer, were used sequentially to improve paper strength. The adsorption of MCN on cellulose fibers was analyzed via polyelectrolyte titration. The formation of MCN/CMC complex in water and the deposition of this complex on silicon wafers were investigated by means of atomic force microscope and quasi-elastic light scattering techniques. The results showed that paper strength was enhanced slightly with a layer-by-layer assembly of the polymers. However, if the washing stage, which was required for layer-by-layer assembly, was eliminated, the MCN/CMC complex was deposited on fibers more efficiently, and the paper strength was improved more significantly. The significant improvement was attributed to the extra development of fiber bonding, confirmed further by scanning electron microscope observation of the bonding area of fibers treated with or without washing. However, the brightness of papers was somewhat decreased by the deposition of the complex on fibers. Higher paper strength also was achieved using rapid drying rather than air drying.

Comparison of UV- and Derivative-Spectrophotometric and HPTLC UVDensitometric Methods for the Determination of Amrinone and Milrinone in Bulk Drugs

2020 ◽  
Vol 16 (3) ◽  
pp. 246-253
Author(s):  
Marcin Gackowski ◽  
Marcin Koba ◽  
Stefan Kruszewski
Keyword(s):  
Thin Layer ◽  
Thin Layer Chromatography ◽  
High Performance ◽  
Low Cost ◽  
Uv Spectra ◽  
Derivative Spectrophotometry ◽  
Therapeutic Monitoring ◽  
Bulk Drug ◽  
Layer Chromatography ◽  
Standard Solutions

Background: Spectrophotometry and thin layer chromatography have been commonly applied in pharmaceutical analysis for many years due to low cost, simplicity and short time of execution. Moreover, the latest modifications including automation of those methods have made them very effective and easy to perform, therefore, the new UV- and derivative spectrophotometry as well as high performance thin layer chromatography UV-densitometric (HPTLC) methods for the routine estimation of amrinone and milrinone in pharmaceutical formulation have been developed and compared in this work since European Pharmacopoeia 9.0 has yet incorporated in an analytical monograph a method for quantification of those compounds. Methods: For the first method the best conditions for quantification were achieved by measuring the lengths between two extrema (peak-to-peak amplitudes) 252 and 277 nm in UV spectra of standard solutions of amrinone and a signal at 288 nm of the first derivative spectra of standard solutions of milrinone. The linearity between D252-277 signal and concentration of amironone and 1D288 signal of milrinone in the same range of 5.0-25.0 μg ml/ml in DMSO:methanol (1:3 v/v) solutions presents the square correlation coefficient (r2) of 0,9997 and 0.9991, respectively. The second method was founded on HPTLC on silica plates, 1,4-dioxane:hexane (100:1.5) as a mobile phase and densitometric scanning at 252 nm for amrinone and at 271 nm for milrinone. Results: The assays were linear over the concentration range of 0,25-5.0 μg per spot (r2=0,9959) and 0,25-10.0 μg per spot (r2=0,9970) for amrinone and milrinone, respectively. The mean recoveries percentage were 99.81 and 100,34 for amrinone as well as 99,58 and 99.46 for milrinone, obtained with spectrophotometry and HPTLC, respectively. Conclusion: The comparison between two elaborated methods leads to the conclusion that UV and derivative spectrophotometry is more precise and gives better recovery, and that is why it should be applied for routine estimation of amrinone and milrinone in bulk drug, pharmaceutical forms and for therapeutic monitoring of the drug.

Adaptation of the AOAC Fluorine Method for Determining Fluoride in Fish Protein Concentrate

1970 ◽  
Vol 53 (1) ◽  
pp. 3-6
Author(s):  
R. Bruce Klemm ◽  
Mary E. Ambrose Klemm
Keyword(s):  
Steam Distillation ◽  
Silica Sand ◽  
Official Method ◽  
Protein Concentrate ◽  
Fish Protein ◽  
Direct Titration ◽  
Modified Method ◽  
Aoac Official ◽  
Aoac Official Method

Abstract The AOAC official method, 24.029–24.035, for the determination of fluorine in foods was modified slightly to o btain quantitative recoveries of fluorine from samples of fish protein concentrate (FPC). The most important alterations include the use of steam distillation, the addition of finely ground silica sand in the distillation, a decrease in the distillation temperature, and the utilization of direct titration. Recoveries of fluoride added to FPC before ashing, using this modified method, averaged 96.0 ± 3.0%. Our results are in agreement with those of several other analysts who used a variety of methods.

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