background : thymol and carvacrol have previously demonstrated larvicidal activity against aedes aegypti (diptera: culicidae). in view of this fact, it was of our interest to obtain synthetic derivatives and evaluate their larvicidal ac­tivity on ae. aegypti larvae. methods : structural modifications were performed on thymol and carvacrol in an effort to understand the functional groups necessa...

Prediction problems from spectra are largely encountered in chemometry. In addition to accurate predictions, it is often needed to extract information about which wavelengths in the spectra contribute in an effective way to the quality of the prediction. This implies to select wavelengths (or wavelength intervals), a problem associated to variable selection. In this paper, it is shown how this ...

Botanical origin of the nectar predominantly affects the chemical composition of honey. Analytical techniques used for reliable honey authentication are mostly time consuming and expensive. Additionally, they cannot provide 100% efficiency in accurate authentication. Therefore, alternatives for the determination of floral origin of honey need to be developed. This study aims to discriminate cha...

The quality of motor fuels is more and strictly controlled in connection with many factors - users are particularly interested the anti-knock resistance automotive gasolines, quantitatively expressed by value research octane number (RON). paper presents FTIR spectrometry conjunction chemometry as an alternative method to standardized determination gasoline a according ?SN EN ISO 5164. An FTIR-P...

A green methodology was developed for the extraction and determination of lauryl ether sulfate in raw materials commercial liquid soap shower gel samples. The method avoids use organic solvents, offering a simple, cheap, safe analysis. is based on sorption an ionic pair consisting cationic dye anionic surfactant onto polyurethane foam. experimental variables were optimized by chemometry to obta...