Quantification of identical and unique segments in ethylene-propylene copolymers using two dimensional liquid chromatography with infra-red detection

Correspondence Quantification in Comprehensive Two-Dimensional Liquid Chromatography

This correspondence corrects the description in a recent paper by Mondello et al., “Quantification in Comprehensive Two-Dimensional Liquid Chromatography” [Mondello, L.; Herrero, M.; Kumm, T.; Dugo, P.; Cortes, H.; Dugo, G. Anal. Chem., 2008, 80, 5418-5424], of previous research on peak integration. This correspondence also shows that the peak integration method proposed in that paper is equiva...

On the Configurational Statistics of Ethylene-Propylene Copolymers

Mean-square unperturbed dimensions {r2)0 and their temperature coefficient d In{r2)0/dT have been calculated for ethylene-propylene copolymers by means of the rotational isomeric state theory of chain molecules. Conformational energies required in the analysis are shown to be readily obtained from previous analyses of polyethylene and polypropylene, without additional approximations. Results th...

Determination of 2-phenylethanol in Rose Water Using Dispersive Liquid-Liquid Microextraction with Gas Chromatography Flame Ionization Detection

A simple and rapid microextraction procedure based on dispersive liquid-liquid microextraction (DLLME) coupled with gas chromatography-flame ionization detection (GC-FID) was developed for the extraction and analysis of 2-phenylethanol in rose water sample. In the proposed approach, carbon tetrachloride and ethanol were used as extraction and dispersive solvents, respectively. Some important pa...

Intracellular delivery of VEGF165 encoding gene therapeutic using trifunctional copolymers of ethylene oxide and propylene oxide

detection of volatile compounds of medicinal plants with some nano-sorbents using modified or new methodologies and investigation of antioxidant activity of their methanolic extracts

in this work, a novel and fast method for direct analysis of volatile compounds (davc) of medicinal plants has been developed by holding a filament from different parts of a plant in the gc injection port. the extraction and analysis of volatile components of a small amount of plant were carried out in one-step without any sample preparation. after optimization of temperature, extraction time a...

Quantification of Lipopeptides Using High-performance Liquid Chromatography with Fluorescence Detection after Derivatization.

A highly sensitive and selective high-performance liquid chromatographic (HPLC) method has been developed for the determination of microbial lipopeptides of fluorescent derivatization with 1-bromoacetylpyrene to overcome the limitations of trace detection of lipopeptides in aqueous solutions. The derivatization of lipopeptides with 1-bromoacetylpyrene was conducted at 60°C for 20 min under cata...