English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Zendy Open

Presents the pdf analysis as premium feature

PDF Analysis

Insights

Presents the summarisation as premium feature

Summarisation

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the zaia usage as premium feature

ZAIA

Zendy Tools

Zendy Plus

Presents the access of premium content as premium feature

Premium Content

The modification of the manual direct two-phase titration method for anionic surface active agent determination is presented. The purpose was to find such organic solvent which can replace solvents applied in the method i. e. chloroform or dichloromethane since both are harmful, exhibiting carcinogenic, mutagenic and, embryotoxic properties. As a new solvent 1-butanol or isobutyl alcohol was used. The reaction in the examined alcohols caused to be acidic during the titration process. Thus the solvatochromic dye (1) i. e. 5-(3-bromo-4-hydroxy-5-methoxyphenyl)-7,7-dimethyl-7H-indolo[1,2-a]quinolinium perchlorate has been replaced with 1-phenyl-2-[2-(3-nitro-4-hydroxy-5-methoxyphenyl)ethenyl]-3,3-dimethyl-3H-indolium perchlorate (2). The pK a  (3.51) of (2) facilitates its dissociation, and has the same color change at the titration endpoint. The modified method was tested on three different concentrations of sodium dodecyl sulfate solution, and the results are in good agreement with the real ones.

tenside surfactants detergents

Manual Direct Two-Phase Titration Method for Anionic Surface Active Agents Determination with Use of Solvatochromic Dye. The Modification Towards Toxicity Abatement