Quantitation of natural triacylglycerols by reversed-phase liquid chromatography with direct liquid inlet mass spectrometry.
Using acetonitrile and propionitrile as eluting solvents and reagent gases the yields of both quasi-molecular and fragment ions were found to vary with the molecular weight, degree of unsaturation and positional distribution of the fatty acids in the triacylglycerol molecule, and appropriate calibration factors were necessary for accurate quantitation. In the absence of pure structural isomers and mixed acid standards, preliminary calibration factors have been determined for total ion and specific ion current responses by comparing the peak area ratios obtained by liquid chromatography-mass spectrometry with the proportions of the molecular species known to be present in randomized oils and in natural oils of known chemical composition. Although the derived factors include both chromatographic and mass spectrometric effects and are obtained with a gradient of reagent gases, they appear to be generally applicable. It was shown that positional isomers affected the yield of the (MH-RCOOH)+ ions over a 1-3-fold range of intensities, while the nature of the fatty acid affected it over a range of 1.25-fold. After suitable calibration of the relative ion responses it was possible to determine the identities and amounts of the individual molecular species in natural fats and oils.
The influence of an electric and magnetic field in chemical reactions
Abstract We have shown that a simultaneous application of uniform and constant electric and magnetic fields cannot affect the equality of the equilibrium enantiomeric populations in a racemic reaction mixture. Hence, whatever the sources of the rotations reported, they cannot have had their origin in uniform applied fields if the reactions have gone to completion.
History, criminology and the ‘use’ of the past
This article considers why, despite an apparent congruence of subject matter and methodologies, the disciplines of sociological criminology and criminal justice history are not more closely aligned. It contends that intellectual traffic between the two fields is not usually limited by institutional barriers, nor is it a legacy of the disciplinary antipathy which existed between history and sociology in Britain during the mid-twentieth century. Rather, it is due to the different ‘purposes’ with which sociological criminologists and criminal justice historians imbue their work and to the differing disciplinary perceptions of the relationship between the past, present and future which result from this. These different ‘purposes’ are traced via a consideration of the paths of development of the two disciplines from the 1940s. The article concludes by proposing an arena for future collaboration between criminal justice historians and sociological criminologists.