in this study, simple and efficient ultrasound-assisted emulsification microextraction (usaeme) combined with gas chromatography-flame ionization detector (gc-fid) was developed for the preconcentration and determination of carbamazepine in biological samples. in this method, the fine droplets of 1-octanol were formed and dispersed in the sample with the help of ultrasonic waves, which accelera...

in this study, we present changes of peroxidase (e. c. 1.11.1. 7) activities in the root of brassica napus var. okapi during rosette stage until ripening of the fruits. peroxidase activity was determined seasonally over an eight month period. results showed that total peroxidase activity in the root was highest in mid june and the lowest activities were observed from time of winter dormancy unt...

in this research, the characteristics of cmp dioxane lignin (hardwood origin) and soda bagasse lignin (ethanol soluble fraction) and dioxane lignin of bagasse were studied using gel permeation chromatography, gas chromatography-mass spectrometry and 13c nmr spectroscopy and dfrc degradation procedure. the results indicated that the main structural units in lignins are phenyl propane skeletons b...

from hexanic extract of aerial parts of peucedanum ruthenicum m. bieb (apiaceae) collected from mazandaran province of iran, four triterpenoids namely taraxasterol, y-taraxasterol, poriferasterol and b-sitosterol have been isolated by column chromatography, thin layer chromatography, and crystallization. their structures were elucidated by spectroscopic methods (uv, ir, ms, 1h and 13c-nmr).