Determination of micromolar concentrations of iodine with aqueous micellar hexadecyltrimethylammonium bromide

1982 ◽  
Vol 54 (4) ◽  
pp. 789-791 ◽  
Author(s):  
Iolanda Midea. Cuccovia ◽  
Hernan. Chaimovich
Keyword(s):  
Hexadecyltrimethylammonium Bromide

A novel reagent for spectroscopic determination of Mo(VI)

2012 ◽  
Vol 66 (1) ◽  
Author(s):  
Sülin Taşcıoğlu ◽  
Esra Kakı ◽  
Senay Taşcıoğlu
Keyword(s):  
Gallic Acid ◽  
Spectrophotometric Determination ◽  
Isoelectric Point ◽  
Hexadecyltrimethylammonium Bromide ◽  
Micellar Effects ◽  
Surface Active Agents ◽  
Binary Complexes ◽  
Molecular Charge ◽  
Surface Active

AbstractA new reagent for spectrophotometric determination of Mo(VI) was developed utilizing micellar effects. For this purpose, differences in the ultraviolet and visible spectral properties of Mo(VI), gallic acid, L-serine, and their binary and ternary solutions were studied in the presence and absence of cationic, anionic, and non-ionic surface active agents. L-serine was observed to form binary complexes and a ternary complex with Mo(VI) and gallic acid below its isoelectric point. The maximum Mo(VI) sensitivity was exerted by the Mo(VI) + gallic acid + L-serine + hexadecyltrimethylammonium bromide system at pH of 4.5. This system was proposed for use in the spectrophotometric determination of Mo(VI) as a superior alternative to the Mo(VI) + gallic acid + hexadecyltrimethylammonium bromide system and to most of the instrumental analysis methods referred to in the literature. The mechanism of micellar effects was discussed on the basis of the spectral data obtained above and below the isoelectric point of L-serine and explained in terms of the molecular charge of the substrates and the surfactants.

Colloidal Aspects of the Formation of the Interactions between Humic Substances and Surfactants

2020 ◽  
Author(s):  
Michal Kalina ◽  
Tomas Duchacek ◽  
Jitka Krouska ◽  
Petr Sedlacek ◽  
Jiri Smilek
Keyword(s):  
Light Scattering ◽  
Humic Substances ◽  
Sodium Dodecyl ◽  
Tween 20 ◽  
Titration Calorimetry ◽  
Hexadecyltrimethylammonium Bromide ◽  
Waste Waters ◽  
Tetradecyltrimethylammonium Bromide ◽  
The Individual

<p>Humic substances (HS) represent fascinating heterogeneous mixture of natural molecules, which possess a high potential to interact with various substances e.g. metals, surfactants, dyes, pesticides. This beneficial property allows their further utilization as the reactive part of sorbents with possible applications in remediation processes of soils and waste waters treatment plants. Surfactants represent a group of substances, which are artificially introduced in the nature by human driven applications causing the undesirable foaming of waters and enhancing the solubility of hydrophobic organic pollutants such as highly toxic polycyclic aromatic hydrocarbons. The present work is focused on the study of colloidal aspects of interactions between selected representatives of surfactants and humic substances, as the example of a promising sorbent and flocculant. For purposes of present work Hexadecyltrimethylammonium bromide, Tetradecyltrimethylammonium bromide, and Carbethoxypendecinium bromide were used as selected cationic surfactants, Sodium dodecyl sulphate as anionic and TWEEN-20 as a non-ionic. The interactions between the individual components were studied by using a combination of dynamic light scattering (determination of the changes in particle size distributions), electrophoretic light scattering (zeta potential – stability investigation) and isothermic titration calorimetry (thermodynamic parameters of interactions) in titration mode of measurement. This set-up provided us the determination of the critical aggregation concentrations of the surfactant-humic system, which corresponded to its phase separation. Moreover, the interactions between the components were confirmed also by routine physico-chemical methods (e.g. thermogravimetry and Fourier transform infrared spectroscopy).  We believe that the outcomes of our work will help to shed a new light on the phenomenon of the formation of the interaction between surfactants and humic substances and will provide the crucial insight in the broader utilization of specific fractions humic substances as the universal sorbent for surfactants mainly from the waste waters.</p>

Fluorescence Enhancement of Carbendazim in the Presence of Cyclodextrins and Micellar Media: A Reappraisal

2005 ◽  
Vol 59 (7) ◽  
pp. 873-880 ◽  
Author(s):  
Rubén M. Maggio ◽  
Gisela N. Piccirilli ◽  
Graciela M. Escandar
Keyword(s):  
Sodium Dodecyl ◽  
Fluorescence Emission ◽  
Hexadecyltrimethylammonium Bromide ◽  
Micellar Media ◽  
Experimental Conditions ◽  
Decyltrimethylammonium Bromide ◽  
Spectrofluorimetric Determination ◽  
Organized Media ◽  
Organized Assemblies

This study focuses on the spectrofluorimetric behavior of the pesticide carbendazim in the presence of selected organized assemblies and also on their potential analytical applications. The relatively weak fluorescence emission band of carbendazim is significantly enhanced by micellar media formed by sodium dodecyl sulfate, hexadecyltrimethylammonium bromide, hexadecyltrimethylammonium chloride, and decyltrimethylammonium bromide. The influence of the surfactant structures, concentrations, and working experimental conditions on the fluorescence spectra of carbendazim was thoroughly evaluated and discussed. Although the interaction of carbendazim with different cyclodextrins is rather weak, it was corroborated that the fluorescence intensity of this compound in the presence of (2-hydroxy)propyl β-cyclodextrin is increased by a factor of two. Among the studied organized media, the cationic surfactant hexadecyltrimethylammonium bromide produced the largest signals for the compound of interest. Consequently, the optimal working conditions for the spectrofluorimetric determination of carbendazim in the presence of the latter detergent were analyzed, concluding that previous literature reports should be reconsidered.

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