I. N. Glazkov

Supercritical fluid extraction of water samples containing ultratrace amounts of organic micropollutants

. Abstract: A true solventless off-line supercritical fluid extraction SFE method has been developed, which does not use organic solvents for trapping and for washing out of analytes. Determination of polynuclear aromatic hydrocarbons, chlorinated pesticides, and polychlorinated biphenyls in aqueous solutions based on their direct SFE extraction and on off-line solventless SFErgas chromatography coupling has been done. This new method has a detection limit at the parts per billionrparts per trillion level. For the ultralow concentration level of 0.1)1 ppt, direct SFE from water was more accurate, faster, and more reproducible than conventional sample preparation methods based on micro-liquidrliquid extraction and solid-phase extraction. Q 1999 John Wiley & Sons, Inc. J Micro Sep 11: 729)736, 1999

Determination of organic compounds in human hair

Data reported in the literature on methods for the determination of organic compounds of different classes in human hair are systematized. Special attention is given to methods for the extraction and preconcentration of organic compounds from hair. A comparative analysis of existing methods is performed.

Combination of supercritical fluid extraction and gas chromatography-mass spectrometry : Determination of impurities extracted from tablet preparations of the benzodiazepine series

A method is proposed for the determination of moderately volatile organic impurities in pharmaceutical tablet preparations based on a combination of solvent-free supercritical fluid extraction (SFE) and gas chromatography-mass spectrometry. The composition of moderately volatile impurities is determined in pharmaceutical tablet preparations of the benzodiazepine series (diazepam, phenazepam, nitrazepam, and clonazepam).

Direct supercritical-fluid extraction of polycyclic aromatic hydrocarbons from aqueous solutions

SummaryThe direct supercritical-fluid extraction (SFE) of polycyclic aromatic hydrocarbons (PAHs) from aqueous solutions was studied. The influence of supercritical fluid pressure and temperature on analyte recovery and kinetics of the direct SFE of PAH mixtures was investigated. A method for PAH determination in water based on their direct supercritical-fluid extraction and on offline solventless coupling with GC was developed. A detection limit for the developed method ppt level was achieved. The water sample was 10 mL The total extracted volume was analyzed by GC-FID or GC-MS.

Supercritical fluid extraction coupled with chromatography-mass spectrometry: Hair analysis. Chromatography-mass spectrometry data processing using the CODA mathematical algorithm

The composition of medium-volatility organic compounds extracted from human hair using supercritical fluid extraction (SFE) was determined. The entire extract was trapped from a gas flow in a sorption device at the extractor outlet and thermally desorbed into a gas chromatography-mass spectrometry (GC-MS) instrument. The extracted compounds were identified either by the direct processing of GC-MS data or using the CODA mathematical algorithm. The combination of solventless SFE with the transfer of the entire extract into a GC-MS instrument with the direct analysis of GC-MS data allowed us to determine organic compounds at a level of 3.9 pg/mg hair. The CODA mathematical algorithm for the processing of GC-MS data allowed us to determine compounds at a level of 1.7 pg/mg hair; in the majority of publications, this determination limit was achieved either by selective ion detection or using a GC-MS-MS technique.

A new approach to comparison of original pharmaceuticals and generics based on comparison of multidimensional impurity profiles using supercritical fluid extraction, liquid extraction, and GC-MS

This paper reports on our effort to study the possibility of comparing the original pharmaceuticals and their analogs (generics) based on comparisons of the multidimensional profiles of impurities isolated from samples by supercritical fluid extraction and liquid extraction and recorded by gas chromato-mass spectrometry (GC-MS) with electron ionization (EI) and atmospheric pressure photochemical ionization (APPhCI). Using the suggested approach makes it possible to increase the number of recorded impurities, to show that the pharmaceutical samples are authentic, and to compare the original pharmaceuticals and generics according to their quality.

Use of stabilized adsorbents for collecting extracts after supercritical fluid extraction

A method was proposed for preconcentrating small amounts of numerous organic contaminants. The method is based on supercritical fluid extraction and trapping the extracted compounds with a multilayer adsorption device followed by their thermodesorption directly to a gas chromatographic system. A method was described for preparing stabilized adsorbents on the basis of a support with a stationary phase using sol-gel synthesis.

Fast Screening of Water and Organic Solution Samples for Polychlorinated Compounds: Microliquid Extraction and GC/MS

Conventional approaches, used to determine polychlorinated organic compounds such as PCDDs, PCBs and CPs in water, are usually based on the time-consuming sample preparation and use of GC/MS with EI ionisation mode or GC coupled with ECD. Long sample preparation procedures and clean-up steps cause losses of solute material, the introduction of new impurities and they are less reliable. Final organic solution volume after sample preparation is usually about lmL. Only a small part of this volume (0.01–0.001) is usually injected into GC/MS. Consequently analysis sensitivity is lost at least by 100 times. Therefore it is important to simplify sample preparation and clean-up steps and to increase the sample volume injected into GC system.