n heptane/dichloromethane

The HPLC enantioseparation of nine atropisomeric 3,3',5,5'-tetrasubstituted-4,4'-bipyridines was performed in normal and polar organic (PO) phase modes using two immobilized polysaccharide-based chiral columns, namely, Chiralpak IA and Chiralpak IC. The separation of all racemic analytes, the effect

The determination of the dispersive component of surface free energies (gamma(s)d) at different temperatures and Lewis acid-base parameters of 1-allyl-3-methylimidazolium chloride ionic liquid ([AMIM]Cl) were investigated by means of inverse gas chromatography (IGC). Four n-alkanes, including

This paper describes the development of methods for selective extraction of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) from soils and sediments, using pressurized liquid extraction with in-cell clean-up (SPLE). Two binary solvent mixtures, viz.

Headspace solid-phase microextraction coupled with cryotrap gas chromatography and mass spectrometry was applied to the analysis of volatile organic compounds in pleural effusions. The highly volatile organic compounds were separated successfully with high sensitivity by the employment of a cryotrap

The aging process of bitumen has been paid more and more attention by the researchers. The four generic fractions (saturates, aromatics, resins and asphaltenes) of bitumen change significantly during the aging process. The analysis of the changes of the four generic fractions of bitumen is very

The concentrations of morphine and codeine were investigated in hair from the head, axillary and pubic regions obtained from 12 fatal heroin cases. Hair preparation involves a decontamination procedure in dichloromethane at 37 degrees C for 15 min, solubilization in sodium hydroxyde at 100 degrees C

A previously developed theoretical model was applied to investigate contaminant breakthrough on charcoal sampling tubes. Associated with the model are two important theoretical parameters. These parameters are k' (a rate constant) and tau (the time required for 50% contaminant breakthrough). In this

The effectiveness of extracting p,p'-DDT and p,p'-DDE from aged contaminated soil samples by means of pressurized liquid extraction (PLE) was evaluated. Two soil samples, which were contaminated more than 10 years ago, were used in the investigation. The static extraction time was optimised and then

The concentrations of morphine and codeine were investigated in hair from the head, axillary and pubic regions obtained from 20 fatal heroin cases. Hair preparation involves decontamination procedure in dichloromethane at 37 degrees C for 15 min, solubilization in sodium hydroxide at 100 degrees C

A sensitive, specific high-performance liquid chromatographic procedure was developed for the determination of plasma drotaverine levels. Basic plasma samples were adjusted to pH 1.5 and extracted with chloroform. HPLC [n-heptane-dichloromethane-diethylamine (50:25:2)] on a microporous silica

A test set of 100 basic drugs has been chromatographed on 16 preselected HPLC-systems using four different types of stationary phase (Si-, NH2-, CN- and C18-). A numerical treatment of the chromatographic data, based on the discriminating power concept, results in the selection of two preferred HPLC

An ultraviolet spectrophotometric procedure for the micro determination of carbamazepine in blood is described which is based on the original 9-methyl-acridine method proposed by Beyer, K.H. and Klinge, K. (1969) (Arzneim-Forsch. 19, 1759--1760). Carbamazepine is extracted from blood with

BACKGROUND Plants of the genus Heracleum L. (Apiaceae) have a long history of being used in traditional medicines for the treatment of alimentary tract disorders, and these biological effects have been ascribed to the presence of furanocoumarins (including bergapten). OBJECTIVE This study aimed to

Datura inoxia belongs to the family of Solanaceae. This is a very common plant in New Caledonia that contains two main toxic alkaloids, l-atropine and l-scopolamine. In this study, we report the case of a 20-year-old male admitted to an Emergency Unit after consumption of 6 dried flowers in hot

A rapid gas-liquid chromatographic method for the estimation of nicotine in plasma is described. Nicotine is extracted from alkalinized plasma into diethyl ether. This is then concentrated by evaporation and, after an acid back extraction is re-extracted into n-heptane (nitrogen detector) or