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Anal Bioanal Chem

Title:		Evaluation of needle trap micro-extraction and automatic alveolar sampling for point-of-care breath analysis
Author(s):		Trefz P; Rosner L; Hein D; Schubert JK; Miekisch W;
Address:		"Department of Anaesthesia and Intensive Care, University of Rostock, Rostock, Germany"
Journal Title:		Anal Bioanal Chem
Year:		2013
Volume:		20130207
Issue:		10
Page Number:		3105 - 3115
DOI:		10.1007/s00216-013-6781-9
ISSN/ISBN:		1618-2650 (Electronic) 1618-2642 (Linking)
Abstract:		"Needle trap devices (NTDs) have shown many advantages such as improved detection limits, reduced sampling time and volume, improved stability, and reproducibility if compared with other techniques used in breath analysis such as solid-phase extraction and solid-phase micro-extraction. Effects of sampling flow (2-30 ml/min) and volume (10-100 ml) were investigated in dry gas standards containing hydrocarbons, aldehydes, and aromatic compounds and in humid breath samples. NTDs contained (single-bed) polymer packing and (triple-bed) combinations of divinylbenzene/Carbopack X/Carboxen 1000. Substances were desorbed from the NTDs by means of thermal expansion and analyzed by gas chromatography-mass spectrometry. An automated CO2-controlled sampling device for direct alveolar sampling at the point-of-care was developed and tested in pilot experiments. Adsorption efficiency for small volatile organic compounds decreased and breakthrough increased when sampling was done with polymer needles from a water-saturated matrix (breath) instead from dry gas. Humidity did not affect analysis with triple-bed NTDs. These NTDs showed only small dependencies on sampling flow and low breakthrough from 1-5 %. The new sampling device was able to control crucial parameters such as sampling flow and volume. With triple-bed NTDs, substance amounts increased linearly with increasing sample volume when alveolar breath was pre-concentrated automatically. When compared with manual sampling, automatic sampling showed comparable or better results. Thorough control of sampling and adequate choice of adsorption material is mandatory for application of needle trap micro-extraction in vivo. The new CO2-controlled sampling device allows direct alveolar sampling at the point-of-care without the need of any additional sampling, storage, or pre-concentration steps"
Keywords:		Adsorption Breath Tests/instrumentation/*methods Gas Chromatography-Mass Spectrometry Humans Needles Point-of-Care Systems Pulmonary Alveoli/*chemistry Solid Phase Microextraction/instrumentation/*methods Volatile Organic Compounds/*analysis/*isolation &;
Notes:		"MedlineTrefz, Phillip Rosner, Lisa Hein, Dietmar Schubert, Jochen K Miekisch, Wolfram eng Evaluation Study Germany 2013/02/08 Anal Bioanal Chem. 2013 Apr; 405(10):3105-15. doi: 10.1007/s00216-013-6781-9. Epub 2013 Feb 7"