title: Enhanced sensitivity in the analysis of trace organochlorine compounds by negative-ion mass spectrometry with ammonia as reagent gas.
abstract: A comparison of the performances of ammonia and methane as reagent gases for the analysis of trace organochlorine compounds by gas chromatography coupled to negative-ion chemical ionization mass spectrometry is performed in the present study. Examples of standard mixtures and human blood samples analyzed with both reagents in scan and selected-ion monitoring mode are shown. Important advantages are observed as a consequence of the use of ammonia. These concern detection and quantitation limits and the lower dependence of sensitivity on the degree of chlorine substitution of the compounds.
authors.affiliation: Department of Environmental Chemistry (CID-CSIC), Barcelona, Catalonia, Spain.
authors.forename: R
authors.initials: R
authors.lastname: Chaler
authors.forename: R
authors.initials: R
authors.lastname: Vilanova
authors.forename: M
authors.initials: M
authors.lastname: Santiago-Silva
authors.forename: P
authors.initials: P
authors.lastname: Fernandez
authors.forename: J O
authors.initials: JO
authors.lastname: Grimalt
mesh_terms: D000641:Ammonia; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006581:Hexachlorobenzene / Q000032:analysis; D006801:Humans; D007202:Indicators and Reagents; D007306:Insecticides / Q000032:analysis* / Q000097:blood; D008697:Methane; D011078:Polychlorinated Biphenyls / Q000032:analysis; D012680:Sensitivity and Specificity
chemical_list: D007202:Indicators and Reagents; D007306:Insecticides; D006581:Hexachlorobenzene; D000641:Ammonia; D011078:Polychlorinated Biphenyls; D008697:Methane