[The use of extractive freezing-out at the stage of preliminary preparation of bioprobes in GC-MS chemico-toxicological analysis]. / Primenenie ékstraktsionnogo vymorazhivaniia na étape predvaritel'noi podgotovki bioprob v GKh-MS khimiko- toksikologicheskom analize.

The authors propose a new express method of low-temperature sample preparation based on the use of extractive freezing-out combined with a sample centrifugation as a stage of a preliminary preparation of a biological object (cadaveric liver, kidneys). The method made it possible to minimize sufficiently the so-called chemical noise of endogenous coextractive substances and to improve sufficiently the conditions of the GC-MS method.

[The determination of pyrovaleron in the urine by gas chromatography in the combination with the method of extractive chilling-out and centrifugation]. / Gazokhromatograficheskoe opredelenie pirovalerona v moche metodom ékstraktsionnogo vymorazhivaniia v sochetanii s tsentrifugirovaniem.

The express-method for the determination of pyrovaleron in the urine based on the combination with the method of extractive freezing-out and centrifugation of the samples as the preliminary stage of the preparation of a biological object for the analysis. The identification and quantitative determination of the substance of interest were performed using gas chromatography with nitrogen-selective detection. The preparation of the samples was carried out as a single-step procedure no longer than 30 min in duration. The limit of alpha-pyrovaleron detection in the urine was estimated at 1 mcg/ml. Its concentration after extraction from the urine increased by a factor of more than nine.