DETector Engineering &Technology, inc.
486 N.Wiget Lane,Walnut Creek, CA 94598 USA
DEl
telephone: (925) 937-4203
fax: (925) 937-7581
e-mail :
innovations in chemical detection
VISITDET at Pln CON 2011, March 13 - 17, Atlanta, Georgia, USA
Booth 4078
Sunday Poster 180-16P
CHEMICAL DETECTION PRODUCTS by DET
featuring novel applications of the principles of
THERMIONIC SURFACE IONIZATION and FLAME IONIZATION
GC detectors and stand-alone transducers manufactured by DET all have an original
common design feature consisting of an electrically heated, cylindrically shaped ion source
element positioned on the axis of an ion collector cylinder. Ion source elements are
fabricated from proprietary ceramic coatings; aremounted on a flange for easy self-aligning
installation into detector tower structures; and are availablewith different ceramic coatings
formultiplemodes of chemical detection using the same basic equipment.
DETECTIONPRINCIPLES USED INDETPRODUCTS:
Thermionic Surface Ionization (TID
&
NPD) - Samples form gas phase negative ions by
extraction of electrons from a hot, catalytically active solid surface. Key parameters are the
surface {composition, surface temperature, gas composition around the surface, and
polarization of the surface relative to a surrounding ion collector. Multiple detectionmodes
are obtained through systematic changes in these four parameters. Some modes, like the
widely used NPD, combine reactive gas phase chemistry to decompose incoming samples,
and then ionize the decomposition products by interactionwith the surface. In other modes,
intact sample molecules are ionized by direct impact with the surface with no intervening
gas phase chemistry.
Conventional Flame Ionization (FlO) - Samples decompose and form ions in gas phase
reactions with radical species like H,
0,
andOH that are present in self-sustained HydrogenÂ
Air flames. A polarizer voltage and ion collector located near the flame effectively measure
ions formed by combustion of organic compounds.
Remote Flame Ionization (RFID) - Like an FlO, samples are decomposed in a self-sustained
flame, but the polarizer and collector electrode are located further downstream of the flame.
In this detection, hydrocarbon ions dissipate by recombination processes near the flame,
and only long lived ion species remain to be selectively measured at the collector.
Detectable ion species include decomposition products of compounds containing P, Pb,
Sn, or Si atoms, and the selectivity versus Hydrocarbon interferences is greatly improved
by using aHydrogen-Methane-Air fueled flame.
Website :
E-mail :
TelNo : 03 9762 2034 . . . inAUSTRALIA
