Endura SpA

A GC/FID/MS method was developed for the identification and quantification of d‐alle thrin (DA) and its major impurities in commercial samples. Optimisation of the experimental conditions was carried out considering such important requirements as resolution, reproducibility, detection limits of 0.1% (m/m) for the impurities, and short analysis time. Under the optimised final conditions the method was validated for specificity, precision (CV% = 0.133 at 2.10 mg/mL and CV% = 0.035 at 3.00 mg/mL), linearity (0–3.00 μg injected), limits of detection (0.09 ng injected) and quantitation (0.28 ng injected), and robustness. The DA related impurities were identified by using a GC/MS method with ion trap mass detection and also by comparison with synthesised standards. The most abundant impurities were crysolactone, allethrolone, chrysanthemic acid, and chloro‐derivatives of DA.

A review.A new environment-friendly synthesis of hydroxyphenylalkylketones was developed operating in vapor phase and using a com. pentasil-type zeolite, obtaining both high conversion values of the phenylacetate feed and high selectivity in the ortho-hydroxyacetophenone, together with a low amount of byproducts.Furthermore, good catalytic performances were also obtained with longer chain esters.The peculiar features of this catalyst-either as such or in the presence of finely ground Al₂O₃ as binder-were investigated by FT-IR spectroscopy, as such or using a non-hindered (acetonitrile) and a hindered nitrile (pivalonitrile) as probes, with a view to explaining its unusual behavior.These data suggest that the catalyst is a modified HZSM5 zeolite, probably externally covered by a layer of terminal silanols, with lowering of acidity and formation of small amounts of defects represented by enlarged channels.The alumina binder does not hinder the access to cavities, but seems to limit the number of defects or their availability.

A new environmentally friendly synthesis of hydroxyphenyl alkyl ketones operating in the vapor phase and using com. solid acid catalysts was developed.The role of reaction conditions and the behavior of different solid acid catalysts were first investigated and correlated to the catalyst features.High conversion values of the phenylacetate feed and high selectivity in o-hydroxyacetophenone, together with a low amount of byproducts, were obtained using a com. pentasil-type zeolite.The features of this catalyst as such or in the presence of finely ground SiO₂ or Al₂O₃ as binder are discussed with a view to explaining its unusual behavior.In addition, good catalytic performances were also obtained with longer chain esters.