Identification of Medicinal Barbiturates by Means of Mass Spectrometry

Rapid determination of barbiturates by gas chromatography-mass spectrometry

“…The postulated fragmentation patterns of the methylated barbituric acid derivatives are presented in Figure 3, and the major fragments for a given compound are listed in Table I according to the scheme presented in Figure 3. The fragmentation patterns are very similar to those previously obtained for unmethylated barbituric acid derivatives (8)(9)(10). They reflect an even higher stability of the ring system than shown by the unmethylated barbiturates.…”

“…The procedure presented here is a modification of the Brochmann-Hansen and Oke methodology and makes use of tri- (1) barbital, (2) probarbital, (3) aprobarbital, (4) butabarbital, (5) amobarbital, (6) pentobarbital, (7) secobarbital, (8) hexethal, (9) glutethimide, (10) phenobarbital, (11) heptabarbital, (12) diphenylhydantoin methylanilinium hydroxide both to extract the barbiturate from the organic phase and to methylate it. This considerably shortens the procedure necessary for the preparation of an injectable fraction for GC-MS identification.…”

The (M-43)+ Ion in the Mass Spectra of Some Medicinal Barbiturates

“…It is our opinion, however, that these authors have wrongly identified some ions in these spectra. An inconsistency with our own work in this field has already been reported (2). We now wish to report that the (M-43)f ion, present in some of the barbiturate spectra, does not have the composition ascribed to it.…”

Development of a Quantitative Gas Chromatography–Tandem Mass Spectrometry Method for the Determination of Pentobarbital in Dog Food

“…This situation was improved by the inclusion of the pentobarbital-d 5 internal standard, as seen in Table 2, where result reproducibility improved with CV ranging from 1.2 to 2.9%. There was a clear demarcation of the majority of these unfortified materials to one sample (sample 3 and its replicate) that had reproducibly varying results on two different 12 Loss of NCO and pyrimidine ring contraction are supported by the study of Miracco et al 13 Native pentobarbital is referred to as d0 and its d 5 -analog is referred to as d5 in this figure. samplings, as a result of sample heterogeneity.…”

“…Proposed origin of significant fragments in pentobarbital. Loss of the alkyl side chain and subsequent loss of CH 3 (CD 3 in d 5 ) from the remaining ethyl group are supported by the study of Coutts and Locock 12. Loss of NCO and pyrimidine ring contraction are supported by the study of Miracco et al13 Native pentobarbital is referred to as d0 and its d 5 -analog is referred to as d5 in this figure.…”