Headspace sampler, determination gases

Summary Polydimethylsiloxanes (PDMS) were cleaved using boron trifluoride etherate under defined conditions in a headspace sampler, and the resulting fluorosilanes were quantified by gas chromatography. The method makes it possible to determine traces of mono- and trifunctional organosiloxy groups in PDMS in concentrations down to... 

Amino acids. Sugars and Organic Acids were analysed as previously described (4). Total Volatiles determination. Volatiles composition and concentration in the samples of melon flesh were determined using a headspace sampler (HP 19393) coupled to a gas chromatograph (HP 5890). Approximately 5g of flesh was obtained by using a cork borer to remove a number of cores from around the equator of the fhiit. This was immediately sealed in a headspace vial, placed in the headspace sampler at a bath temperature of 100 C, equilibrated for 15min before analysis on an HP 5890 GC equipped with an FID detector and fitted with a 30m x 0.32mm i.d. OVl fused silica colunm. 

Headspace and thermal desorption are thermal extraction methods which can be directly connected to gas chromatography and do not need additional sample preparation. Usually both methods are applied for the determination of volatile compounds in air and water. Only few applications are known for the direct treatment of soil samples. The investigations for analysis of phenylarsenic compounds were carried out with an Headspace Sampler HS40 (Perkin-Elmer Inc.) and a Thermal desorption system TDS 2 (Gerstel GmbH, Germany). 

Gadelle and co-workers [13,14] used a Hewlett Packard headspace sampler (HP-19395A) connected to a Hewlett Packard gas chromatograph (HP5890) equipped with a capillary column and a flame ionisation detector to determine benzene, chlorobenzene, toluene and xylene in ethylene oxide propylene oxide tri block copolymers. The headspace sampler consists of a valve and loop system to inject a vapour sample of a known volume (1 pi) into the gas chromatograph. Peak areas are then determined by a Hewlett Packard integrator (HP 3393A). 

Elke, K., Jermann, E., Begerow, J., and Dunemann, L., Determination of benzene, toluene, ethylbenzene and xylenes in indoor air at environmental levels using diffusive samplers in combination with headspace solid-phase microextraction and high-resolution gas chromatography-flame ionization detection, J. Chromatogr. A, 826(2), 191-200, 1998. 

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