ISSN:
0306-042X
Keywords:
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The [M-1]- ion sometimes observed in the methane electron capture/negative chemical ionization mass spectra of diazepam and nordiazepam is [M-H]-. Generation of the [M-H]- ion is caused by trace amounts of oxygen in the ion source. For nordiazepam the Hż lost from the [M]-ż ion is that on the amide nitrogen. For diazepam the Hż lost from the [M]-ż ion is that on the carbon adjacent to the amide carbonyl. The [M-1]- ion generated by negative chemical ionization is structurally different from the [M-1]+ ion generated by positive electron ionization. At ion source temperatures greater than 150°C, the methane electron capture/negative chemical ionization mass spectra of diazepam and nordiazepam consist principally of [Cl]- ions. A comparison of the relative sensitivities of various analogs of diazepam and nordiazepam suggests that electron capture occurs at the imine bond.
Additional Material:
2 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/bms.1200100305
