Selective Detectors forGas Chromatography
ELCD
PFPD
XSD
PID
PID/FID
PID/ELCD
PID/XSD
While gas chromatography coupled with mass spectrometry (GC-MS) is a powerful analytical technique, there are significant advantages to using selective GC detectors alone or in tandem with a MS detector for many applications.
A mass spectrometer is a universal, nonselective detector that yields total ion chromatograms containing a large number of compounds. Post-run mass spectra library searching is required to identify target compounds.
Selective GC detectors enhance chromatographic performance by measuring trace levels of target compounds in the presence of higher concentration compounds, or matrix interferences.
Selective GC detectors provide precise retention time marking for improved MS library matching and peak identification.
Co-elution of interferences in essential oils can make locating compounds responsible for characteristic aromas in a MS chromatogram quite difficult. The accompanying GC-MS total ion chromatogram of galbanum oil contains a large number of co-eluted compounds. A simultaneous sulfur mode PFPD chromatogram helps pinpoint sulfur compounds contributing to the fragrance profile of the oil.
Enhancing Chromatographic Performance
Selective GC Detectors for Challenging Analytical Applications
OI Analytical selective GC detectors provide solutions to challenging analytical applications. Detecting sulfur species in petrochemicals, trace levels of organochlorine and organophosphorus pesticides in food samples, or sulfur and aromatic compounds in flavor and fragrance extracts are prime examples of applications that benefit from the use of selective GC detectors.
Compatible detectors are available for current models of GC instruments manufactured by Agilent, Bruker, Shimadzu, Thermo, and PerkinElmer.
Aromatics
Alkenes
Arsenic/Tin
BTEX
Chemical Weapon Agents (CWA)
Chlorinated Pesticides
Chlorinated VOC’s
Herbicides
Olefins
Organofluoride Compounds
PCBs
Phosphorus Compounds
S/P Pesticides
Sulfur Compounds
Trihalomethanes (THM)
VOCsSimultaneous sulfur mode PFPD chromatogram of galbanum oil.
FID chromatogram of galbanum oilGC-MS total ion chromatogram of galbanum oil.
Abundance
5e+07
4.5e+07
4e+07
3.5e+07
3e+07
2.5e+07
2e+07
1.5e+07
1e+07
5000000
Time 20.00 40.00 60.00
20.00 40.00 60.00
Abundance2.2e+07
2e+07
1.8e+07
1.6e+07
1.4e+07
1.2e+07
1e+07
8000000
6000000
4000000
2000000
Time 20.00 40.00 60.00
Abundance 1600000
1500000
1300000
1200000
1100000
1000000
900000
800000
700000
600000
500000
400000
Time 34.00 35.00 36.00 37.00 38.00 39.00 40.00
Abundance1e+07
9000000
8000000
7000000
6000000
5000000
4000000
3000000
2000000
1000000
Time
Selective GC Detectors
151 Graham RoadPO Box 9010College Station, Texas 77842-9010
(979) 690-1711(800) 653-1711 USA/CanadaFAX (979) 690-0440
www.oico.comE-mail: [email protected]
Publication 31670116
PFPD – Pulsed Flame Photometric DetectorThe PFPD excels at selective detection of sulfur and phosphorus compounds, and can be confi gured to detect 26 other elements.
XSDTM – Halogen Specifi c DetectorThe XSD halogen specifi c detector is designed for selective detection of halogenated compounds such as pesticides, THMs, and PCBs.
Tandem GC DetectorsOI Analytical patented* tandem GC detectors combine a photoionization detector (PID) with an FID or second selective detector providing two simultaneous chromatograms from a single run. The PID selectively responds to aromatic and unsaturated hydrocarbons in the presence of alkanes and saturated hydrocarbons. The second detector is used to further differentiate and identify compounds with specifi c heteroatoms.
ELCD-Electrolytic Conductivity DetectorThe ELCD is designed for high sensitivity measurement of halogenated compounds. Interfacing an ELCD with a PID as tandem detectors is prescribed in USEPA methods 502.2 and 8021 for measurement of chlorinated and aromatic volatile organic compounds (VOCs) in drinking water and wastewater samples.
* U.S. Patents 4,804,846 and 5,578,271