Mass Spectrometric Determination of Unresolved Components in Gas Chromatographic Effluents.

Determination of chlorinated dibenzo-p-dioxins and dibenzofurans in various materials.

“…When this method was applied to a 1-g sample of material used by Bionetics Research Laboratory in a teratology study (14), the results shown in Figure 1 were obtained. The use of gas-liquid chromatography in combination with mass spectrometry (GC-MS) offers significant potential for selective determination of particular components in complex mixtures (15,16). Figure 2 shows the schematic diagram of the GC-MS which uses the Becker-Ryhage double molecular jet separator.…”

High‐resolution isotope‐dilution mass spectrometry using metabolism of isotope‐labeled compounds: Application to drug metabolites

“…In this manuscript we describe the analytical utility of revisiting this approach, but employing (stable) isotope dilution mass spectrometry (IDMS) of organic molecules and all of the well-documented, and considerable, advantages of this quantitative technique when applied to the analysis of organic molecules. [1][2][3] Note: The term stable isotope dilution MS will not be used here since IDMS is the more generic term, and whether an isotope is radioactive or not is unimportant in our context. The term 'stable isotope labeled' will be used when appropriately referring to a labeled compound.…”

“…In pharmacology, quantitative (kinetic) and qualitative analysis of the radioactive constituents in tissues and fluids in vivo and in excreta following administration of a 14 C-labeled drug is a standard protocol required for drug development and registration (radiolabeled distribution, or 'mass balance', and metabolism study; the quantitative and qualitative analysis of drug-related material). Far earlier in the drug discovery and development process, questions related to the biotransformation of drugs occur and these include: (1) What are the rates of metabolism across species in vitro and in vivo and what is the role of metabolism in drug clearance (CL), and (2) What is the qualitative nature of the drug metabolite profile including formation of reactive metabolites? It is important to determine not only the qualitative nature of the drug metabolic profile, but to also make a reasonable estimate of the amounts of drug metabolites produced in preclinical species and in man.…”

Determination of Serum Glucose by Isotope Dilution Mass Spectrometry

“…We used 13C glucose instead of deuterium labeled glucose, because isotope effects from deuterium, such as the separation of labeled material from natural one on the GC column, have often been reported and discussed. 2 From a mass spectrometric measurement the unlabeled glucose content in the labeled glucose we used was estimated to be less than 1%.…”