Gcms/pops
Hybrid technique which couples: the powerful separation potential of gas chromatography with the specific characterization ability of mass spectroscopy thanks to data banks constituted by more 350 000 mass spectra recorded in EI mode (70eV)
Gas Chromatography-Mass Spectrometry: case of Persistent Organic Pollutants (POPs)
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COUPLING GC-MS
Contents of the NIST/EPA/NIH Mass Spectral Library
LIBRARY NAME LIBRARY DESCRIPTION LIBRARY CONTENTS
Mainlib replib nist_salts nist_msms A mixture of compounds is separated by gas chromatography, then identified by mass spectrometry.
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Main EI/MS library Replicate spectra EI Salt Library MS/MS Library
191,436 spectra 28,307 spectra 717 spectra 14,802 spectra of
3,898 positive and 1,410 negative ions
nist_ri
Retention Index Library
293,247 Kovats RI values for 4 44,008 compounds
What is GC? a Separation Technique Sample is usually a complex mixture which requires to be separated into constituent components. Usually used to quantify some or all components e.g. Pharmaceuticals, Environmenmental pollutants, etc
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Persistent Organic Pollutants (POPs)
Pesticides (HCB, DDT, HCH, Toxaphene) Industrial Products, TIC : PolyChlorinated Biphenyls (PCBs),
POPs: the dirty dozen
Are toxic, bioaccumulate in fatty tissues of animals and humans and do not easily degrade Composed by: 8 chlorinated pesticides (dieldrin, endrin, aldrin, chlordane, heptachlor, DDT,mirex and toxaphene) two industrial chemicals (hexachlorobenzene (HCB) and polychlorinated biphenyls (PCBs)) two unintentionally produced compounds (polychlorinated dibenzo-p-dioxins (PCDDs)), also abbreviated as dioxins, and polychlorinated dibenzofurans (PCDFs), also abbreviated as furans)
- dielectric fluids for capacitors & transformers
– heat transfer fluids, lubricating & cutting oils – additives in pesticides, paints, adhesives, sealants, plastics, flame retardants, surgical implants
By-Product of combustion