IN-BEAM ELECTRON IMPACT, CHEMICAL IONIZATION AND NEGATIVE ION CHEMICAL IONIZATION OF FLAVONOID GLYCOSIDES

1982 ◽  
Vol 11 (1) ◽  
pp. 49-52 ◽  
Author(s):  
Hideji Itokawa ◽  
Yoshiaki Oshida ◽  
Akira Ikuta ◽  
Yasuo Shida
Keyword(s):  
Electron Impact ◽  
Chemical Ionization ◽  
Negative Ion ◽  
Flavonoid Glycosides ◽  
Beam Electron ◽  
Negative Ion Chemical Ionization

Determination of 3,3'-Dichlorobenzidine in Industrial Wastewaters

2004 ◽  
Vol 39 (1) ◽  
pp. 29-34 ◽  
Author(s):  
Hing-Biu Lee ◽  
Thomas E. Peart ◽  
Ken Terry ◽  
James Maguire
Keyword(s):  
Electron Impact ◽  
Chemical Ionization ◽  
Solid Phase ◽  
Negative Ion ◽  
Gas Chromatography Mass Spectrometry ◽  
Ms Detection ◽  
Negative Ion Chemical Ionization ◽  
Ionization Mode ◽  
Wastewater Samples

Abstract A solid-phase extraction, chemical derivatization, and gas chromatography/mass spectrometry (GC/MS) method has been developed for the determination of trace 3,3'-dichlorobenzidine (DCB) in industrial wastewater samples. Instead of an octadecylsilane (ODS) cartridge, a Porapak RDX cartridge was used since the latter could be optimized for the extraction of DCB. After the pre-concentration, interfering coextractives in the sample were selectively removed from the cartridge by elution with a 1:1 mixture of acetonitrile and water. DCB was then eluted with acetonitrile and derivatized with pentafluoropropionic acid anhydride. The product was subsequently analyzed by GC/MS in either the electron impact or negative ion chemical ionization mode. Recoveries of DCB and the surrogate, DCB-d6, were better than 90% at spiking levels of 10, 1, and 0.1 µg/L. Based on a concentration factor of 100, the detection limits for DCB in wastewater samples were determined to be 0.1 µg/L by electron impact GC/MS detection, and 0.01 µg/L by negative ion chemical ionization GC/MS detection, respectively. This method has been successfully applied to wastewater samples collected in the Toronto area.

Pulsed Positive Ion-Negative Ion Chemical Ionization Mass Spectrometry of Animal Drugs: Sulfonamides

1980 ◽  
Vol 63 (3) ◽  
pp. 452-459 ◽  
Author(s):  
John A G Roach ◽  
James A Sphon ◽  
Donald F Hunt ◽  
Frank W Crow
Keyword(s):  
Mass Spectrometry ◽  
Electron Impact ◽  
Chemical Ionization ◽  
Impact Analysis ◽  
Negative Ion ◽  
Ionization Mass ◽  
Sulfa Drugs ◽  
Single Experiment ◽  
Negative Ion Chemical Ionization ◽  
Positive Ion

Abstract The analysis of sulfa drugs, using pulsed positive ion-negative ion chemical ionization (PPINICI) mass spectrometry (MS), generates both positive and negative spectra in a single experiment. The spectra afforded by PPINICI-MS permit systematic interpretation and prediction of fragmentation for this class of compounds. Comparison of the electron impact and PPINICI spectra of 17 sulfa drugs and selected derivatives demonstrates that the useful information available with this new technique exceeds that afforded by electron impact analysis.

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