On-line hydrogenation in GC-MS analysis of cyclic fatty acid monomers isolated from heated linseed oil
A simple on-line hydrogenation method in GC-MS analysis of unsaturated fatty acid esters is described. Using hydrogen as carrier gas, hydrogenation takes place in a capillary reactor connected to the outlet of the analytical column in the oven of the gas chromatograph. The reactor is a fused silica tube (60 cm×0.32 mm i.d.) coated with palladium acetylacetonate. Selective hydrogenation of olefinic bonds is achieved after a normal chromatographic run. Structural information (carbon-skeleton, double bond equivalents) can thus be deduced, and structural correlations between the saturated and unsaturated components can be obtained. Structures of cyclic fatty acid esters isolated from heated linseed oil were elucidated using this simple method which was found very useful for structural investigations on unsaturated compounds by GC-MS.
Special techniques in the combination of gas chromatography and mass spectrometry
Abstract On the basis of a new open split-type connection of a gas chromatograph and a mass spectrometer, particularly suitable for glass capillary columns, procedures are described for decreasing a peak concentration that is too high by dilution and increasing a maximum peak concentration that is too low by trapping and subsequent evaporation. On-line hydrogenation in a glass capillary reactor with palladium as catalyst and its analytical application is described. A low-cost quadrupole mass spectrometer as an independent detector has been mounted inside a mass spectrometer. The resulting possibilities and advantages are discussed.
The German centenary of the First World War
In the run up to the 2014 centenary of the First World War, the German public was gripped by a heated debate on the origins of the war. This article explores the nature of this controversy and its role in shaping national commemoration of the Great War. It also draws parallels between the commemorations of the fiftieth anniversary of the outbreak of the war in 1964 and those of 2014. Through a comparison of Germany’s national memories of the war with those in Britain and France, the article also reveals how different and sometimes conflicting national interpretations of the history of the First World War have affected centenary commemoration. Memories of the First World War are nation-specific, constructed and developed over time to suit a particular view of a country’s past. Moreover, they can be instrumental in influencing that country’s future development and relations with its neighbours.