The oxidation of n‐heptane has been studied in a jet‐stirred flow reactor in the temperature range 950–1200 K at atmospheric pressure for a wide range of fuel‐oxygen equivalence ratios (0.2 to 2.0). A chemical kinetic reaction mechanism developed from previous studies on smaller hydrocarbons and extended to C6 and C7 species was used to reproduce the experimental data. Good agreement between computed and measured concentrations of major chemical species was obtained for the entire range of experimental conditions. Sensitivity analyses were carried out to identify the reactions having the greatest influence on the modeling results. The major reaction paths for n‐heptane consumption and for the formation of the main products have been identified. In addition n‐heptane ignition delays behind a reflected shock wave measured by other investigators were used to validate the present reaction mechanism at higher temperature and pressure.

The oxidation of n-heptane has been studied in a jet-stirred flow reactor in the temperature range 950-1200 K at atmospheric pressure for a wide range of fuel-oxygen equivalence ratios (0.2 to 2.0). A chemical kinetic reaction mechanism developed from previous studies on smaller hydrocarbons and extended to Cs and C? species was used to reproduce the experimental data. Good agreement between computed and measured concentrations of major chemical species was obtained for the entire range of experimental conditions. Sensitivity analyses were carried out to identify the reactions having the greatest influence on the modeling results. The major reaction paths for n-heptane consumption and for the formation of the main products have been identified.In addition n-heptane ignition delays behind a reflected shock wave measured by other investigators were used to validate the present reaction mechanism at higher temperature and pressure.

Résumé -Introduction : Datura stramonium L., du nom local Chdeq ej-jmel, est utilisé en médecine traditionnelle marocaine. Matériels et méthodes : L'extrait organique issu des graines sèches réduites en poudre de Datura stramonium L. récoltées dans la région de Kénitra (ouest marocain) a été analysé par chromatographie gazeuse couplée à la spectrométrie de masse. Résultats : L'analyse a permis l'identification de huit alcaloïdes tropaniques, dont le 6-hydroxyatropine et le 6-hydroxyapoatropine qui sont détectés pour la première fois dans les graines de cette espèce. Par ailleurs, les analyses en chromatographie liquide couplée à la spectrométrie de masse ont confirmé que l'atropine et la scopolamine sont les alcaloïdes majoritaires. Discussion et conclusion : Ces deux agents antimuscariniques sont responsables, selon la dose, de sédation ou de délires hallucinatoires recherchés par les usagers. Mots clés : Datura stramonium L., graines, alcaloïdes tropaniques, CPG-SM, CLHP-SM Abstract -Introduction: Datura stramonium L. (Chdeq ej-jmel)is a traditional medicine used in Morocco. Materials and methods: Qualitative analyses of the basic extract of tropane alkaloids in seeds of Datura stramonium L. collected in the region of Kénitra (west of Morroco) were carried out by GC/MS. Results and discussion: Eight tropane alkaloids were identified. Six of these alkaloids were described in previous works, and the other two (6-hydroxyatropine and 6-hydroxyapoatropine) are reported for the first time for this species in the present work. On the other hand, analyses by LC/MS confirmed that atropine and scopolamine are the main tropane alkaloids in seeds of Datura stramonium L. Conclusion: These two drugs are involved in the hallucinogenic and sedative effects of the plant.