Quantitation of 20-hydroxy-5,8,11,14-eicosatetraenoic acid (20-HETE) produced by human polymorphonuclear leukocytes using electron capture ionization gas chromatography/mass spectrometry

1992 ◽  
Vol 21 (5) ◽  
pp. 249-253 ◽  
Author(s):  
Elizabeth Hill ◽  
Robert C. Murphy
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Electron Capture ◽  
Polymorphonuclear Leukocytes ◽  
Eicosatetraenoic Acid ◽  
Gas Chromatography Mass Spectrometry ◽  
Chromatography Mass Spectrometry ◽  
Human Polymorphonuclear Leukocytes

Determination of Polychlorodibenzo-p-dioxins and Related Compounds in Commercial Chlorophenols

1972 ◽  
Vol 55 (1) ◽  
pp. 85-92 ◽  
Author(s):  
David Firestone ◽  
John Ress ◽  
N L Brown ◽  
R P Barron ◽  
J N Damico
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Electron Capture ◽  
Gas Chromatography Mass Spectrometry ◽  
Alumina Column ◽  
Spectrometric Data ◽  
Chromatography Mass Spectrometry ◽  
Related Compounds ◽  
Chromatographic Mass

Abstract Twenty-one commercial chlorophenols were examined for the presence of polychlorodibenzo- p-dioxins (chlorodioxins) and related compounds. The chlorophenols were dissolved in aqueous alkali, extracted with petroleum ether, and fractionated on an alumina column. Alumina fractions were examined by electron capture gas chromatography and combined gas chromatography-mass spectrometry. Chlorodioxin content was estimated by electron capture gas chromatography. The presence of chlorodioxins, polychlorodibenzofurans (chlorofurans), and polychlorodiphenyl ethers (chloroethers) was confirmed by combined gas chromatography-mass spectrometry. The 2,3,-7,8-tetrachlorodioxin was found in 3 of 6 samples of 2,4,5-trichlorophenol but was not detected in any of the 11 samples of tetra- and pentachlorophenol that were examined. Hexachlorodioxin was present at levels ranging from 0.17 to 39 ppm in all 8 pentachlorophenols examined. Hexa-, hepta-, and octachlorodioxins as well as a wide variety of chlorofurans and chloroethers of varying chlorine content were present in most of the tetra- and pentachlorophenols. In addition, the gas chromatographic- mass spectrometric data suggested that some of the chlorophenols contained methoxy- and dimethoxypolychlorofurans and methoxypolychloroethers as well as polychlorohy droxybiphenyl.

scholarly journals Rapid Determination of Imazapyr in Corn by Gas Chromatography/Mass Spectrometry with Electron Capture Negative Ion Chemical Ionization

1996 ◽  
Vol 79 (5) ◽  
pp. 1220-1226 ◽  
Author(s):  
Steven J Stout ◽  
Adrian R Dacunha ◽  
J Shahn Fletcher ◽  
Gerald L Picard
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Electron Capture ◽  
Chemical Ionization ◽  
Rapid Determination ◽  
Negative Ion ◽  
Gas Chromatography Mass Spectrometry ◽  
Chromatography Mass Spectrometry ◽  
Negative Ion Chemical Ionization ◽  
Cleanup Procedure

Abstract Imazapyr, an imidazolinone class herbicide, was developed recently for weed control in imidazolinonetolerant corn. Current methods for determining imidazolinone herbicides in crops involve laborious, time-consuming cleanup procedures after extraction. We developed an extremely simple cleanup procedure for imazapyr in corn commodities after extraction with acidic acetone-water by using gas chromatography/mass spectrometry with electron capture negative ion chemical ionization for final detection. Method sensitivity was 50 ppb, with controls showing <5 ppb. Average recoveries from corn forage, fodder, and grain were 98,106, and 101%, respectively.

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