« Previous AbstractWhat mosquitoes want: secrets of host attraction    Next Abstract"Simultaneous sampling and analysis of indoor air infested with Cimex lectularius L. (Hemiptera: Cimicidae) by solid phase microextraction, thin film microextraction and needle trap device" »

J Sep Sci

Title:		Simple sample transfer technique by internally expanded desorptive flow for needle trap devices
Author(s):		Eom IY; Pawliszyn J;
Address:		"Department of Chemistry, University of Waterloo, Waterloo, Ontario, Canada"
Journal Title:		J Sep Sci
Year:		2008
Volume:		31
Issue:		12
Page Number:		2283 - 2287
DOI:		10.1002/jssc.200800024
ISSN/ISBN:		1615-9314 (Electronic) 1615-9306 (Linking)
Abstract:		"Needle trap devices (NTDs) are improving in simplicity and usefulness for sampling volatile organic compounds (VOCs) since their first introduction in early 2000s. Three different sample transfer methods have been reported for NTDs to date. All methods use thermal desorption and simultaneously provide desorptive flow to transfer desorbed VOCs into a GC separation column. For NTDs having 'side holes', GC carrier gas enters a 'side hole' and passes through sorbent particles to carry desorbed VOCs, while for NTD not having a 'side hole', clean air as desorptive flow can be provided through a needle head by a air tight syringe to sweep out desorbed VOCs or water vapor has been reported recently to be used as desorptive flow. We report here a new simple sample transfer technique for NTDs, in which no side holes and an external desorptive flow are required. When an NTD enriched by a mixture of benzene, toluene, ethylbenzene, and xylene (BTEX) or n-alkane mixture (C6-C15) is exposed to the hot zone of GC injector, the expanding air above the packed sorbent transfers the desorbed compounds from the sorbent to the GC column. This internal air expansion results in clean and sharp desorption profiles for BTEX and n-alkane mixture with no carryover. The effect of desorption temperature, desorption time, and overhead volumes was studied. Decane having vapor pressure of approximately 1 Torr at 20 degrees C showed approximately 1% carryover at the moderate thermal desorption condition (0.5 min at 250 degrees C)"
Keywords:		"Adsorption Chromatography, Gas/instrumentation/*methods Equipment Design Organic Chemicals/*analysis Volatilization;"
Notes:		"MedlineEom, In-Yong Pawliszyn, Janusz eng Germany 2008/06/20 J Sep Sci. 2008 Jul; 31(12):2283-7. doi: 10.1002/jssc.200800024"