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Anal Chem

Title:		Silicon microfabricated column with microfabricated differential mobility spectrometer for GC analysis of volatile organic compounds
Author(s):		Lambertus GR; Fix CS; Reidy SM; Miller RA; Wheeler D; Nazarov E; Sacks R;
Address:		"Department of Chemistry, University of Michigan, Ann Arbor, 48109, USA"
Journal Title:		Anal Chem
Year:		2005
Volume:		77
Issue:		23
Page Number:		7563 - 7571
DOI:		10.1021/ac051216s
ISSN/ISBN:		0003-2700 (Print) 0003-2700 (Linking)
Abstract:		"A 3.0-m-long, 150-microm-wide, 240-microm-deep channel etched in a 3.2-cm-square silicon chip, covered with a Pyrex wafer, and coated with a dimethyl polysiloxane stationary phase is used for the GC separation of volatile organic compounds. The column, which generates approximately 5500 theoretical plates, is temperature-programmed in a conventional convection oven. The column is connected through a heated transfer line to a microfabricated differential mobility spectrometer. The spectrometer incorporates a 63Ni source for atmospheric-pressure chemical ionization of the analytes. Nitrogen or air transport gas (flow 300 cm(3)/min) drives the analyte ions through the cell. The spectrometer operates with an asymmetric radio frequency (RF) electric field between a pair of electrodes in the detector cell. During each radio frequency cycle, the ion mobility alternates between a high-field and a low-field value (differential mobility). Ions oscillate between the electrodes, and only ions with an appropriate differential mobility reach a pair of biased collectors at the downstream end of the cell. A compensation voltage applied to one of the RF electrodes is scanned to allow ions with different differential mobilities to pass through the cell without being annihilated at the RF electrodes. A unique feature of the device is that both positive and negative ions are detected from a single experiment. The combined microfabricated column and detector is evaluated for the analysis of volatile organic compounds with a variety of functionalities"
Keywords:		"Chromatography, Gas/*instrumentation/*methods Organic Chemicals/*chemistry Silicon/*chemistry Temperature Volatilization;"
Notes:		"MedlineLambertus, Gordon R Fix, Cory S Reidy, Shaelah M Miller, Ranaan A Wheeler, David Nazarov, Erkinjon Sacks, Richard eng R01-OH03692/OH/NIOSH CDC HHS/ Research Support, N.I.H., Extramural Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, Non-P.H.S. 2005/12/01 Anal Chem. 2005 Dec 1; 77(23):7563-71. doi: 10.1021/ac051216s"