By analogy to gas chromatography/mass spectrometry, mass separation/mass spectral characterization (MS/MS) is defined as an analytical method in which mass spectrometry is used both for separation and for identification of the components of a mixture; identification utilizes collisional activation (CA) and metastable ion (MI) mass spectra. The applicability and potentialities of MS/MS are explored in terms of the sensitivity, selectivity, and value of the analytical information obtainable from a variety of organic mixtures. Different ionization methods are found to have complementary advantages. Interpretation of MI/CA mass spectra of molecular (M+), (M + H)+, and fragment ions using known correlations can provide valuable structural information, although computer matching of such spectra against reference electron-ionization mass spectra was relatively unsuccessful. As examples of specific detection of particular trace components In a complex mixture, thiophene, tetrahydropyran, and n-propylbenzene can be detected in gasoline at levels of <25 ppm, <50 ppm, and <500 ppm, respectively.

Die Titelverbindung (IV) wird als Dicyclohexylammoniumsalz ausgehend vom [′70]‐ P‐oxychlorid (I) und (‐)‐Ephedrin (II) dargestellt.

2-(5'-Coumaranyl)-exo-5,6-trimethylene-2-em/o-norbomanol was made by the addition of 5-coumaranyllithium5 [made from 5-bromocoumaran (16 g, 0.08 mol) and n-butyllithium (1.9 M, 42 mL, 0.08 mol)] in ether to exo-5,6-trimethylene-2-norbornanone (10.5 g, 0.07 mol) in ether at 0 °C. The endo alcohol was recrystallized from hexane-chloroform (70:30) to get the pure alcohol in 69% yield, mp 119-120 °C.

No abstract

Collisional acthation mass spectra confirm that tolyl ions can be produced from a variety of CH,C.&Y compounds. High pnrity 0-, mand ptolyl ions are prepared by chemical ionization of the corresponding fluorides (Y=F) as proposed by Harrison. In electron ionization of CW3C,&Y formation of the more stable tropylium and benzyl ionic isomers usually accompanies that of the 0-, m-and p-tolyl ions. Isomerhation of low energy [CH3C&€hY]+ * to [Y-methylenecyclohexadienel+' is proposed to account for most [benzyll+ formation, while the tropyfium ion appears to arke from the isomerization of tolyl ions formed with higher internal energies, [o-, m-, p-tolyl]+ -+ [benzyll+ -+ [tropylium]+, consistent with Dewar's predictions from MIND0/3 calculations.