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.
On-line hydrogenation of biodiesel-Toward a reference method for the determination of glycerides and total glycerol.
A reliable method with ensured traceability of the measurement results for free and bound glycerol (as monoacylglycerides, diacylglycerides and triacylglyerides) in biodiesel was developed, giving results beyond the state of the art of the current standard methodologies. The proposed method is based on an on-line hydrogenation using gas chromatography coupled to flame ionization detection and hydrogen as carrier gas. After sample introduction the hydrogenation takes place on a fused silica pre-column coated with a palladium catalyst. This approach allows an immediate and reliable hydrogenation of vegetable oils and biodiesels from different feedstocks. All glycerides are converted into their saturated analogues, resulting in simplified chromatograms with structurally clearly defined analytes, and increased sensitivity for trace amounts of compounds. The method has been successfully in-house validated and combined uncertainty values have been assigned to the final results, which were less than 8% for free glycerol, the sum of monoacylglycerides, the sum of diacylglycerides and the sum of triacylglycerides.
The Invention of the Jewish People
'All modern nation states have a story of their origins, passed down through both official and popular culture, and yet few of these accounts have proved as divisive and influential as the Israeli national myth. The well-known tale of Jewish exile at the hands of the Romans during the first century AD, and the assertion of both cultural and racial continuity through to the Jewish people of the present day, resonates far beyond Israel's borders. Despite its use as a justification for Jewish settlement in Palestine and the project of a Greater Israel, there have been few scholarly investigations into the historical accuracy of the story as a whole. In this bold and ambitious new book, Shlomo Sand shows that the Israeli national myth has its origins in the nineteenth century, rather than in biblical times - when Jewish historians, like scholars in many other cultures, reconstituted an imagined people in order to model a future nation. Sand forensically dissects the official story - and demonstrates the construction of a nationalist myth and the collective mystification that this requires. A bestseller in Israel and France, Shlomo Sand's book has sparked a widespread and lively debate. Should the Jewish people regard themselves as genetically distinct and identifiable across the millennia - or should that doctrine now be left behind and if the myth of the Jewish state is dismantled, could this open a path toward a more inclusive Israeli state, content within its borders?'