Supercritical fluid chromatography of industrial paraffins and waxes

Summary The application of capillary SFC for SIMDIST investigations of paraffins and waxes is reported. Pressure, density and temperature of the mobile phase are optimized to obtain high chromatographic resolution of complex mixtures of industrial products. Isothermal linear pressure programming and asymptotic pressure and density programming are used in the range from 15 to 35 MPa in the isothermic mode above 100°C. SFC chromatograms of natural and synthetic paraffins, microcrystalline wax and candle wax are compared. The retention behaviour of paraffin mixtures and waxes has been investigated on methyl/phenyl and biphenyl capillary columns. The polarity of the stationary phases influences the absolute retention time more than it influences the chromatographic resolution.     

Indirect electrochemical methods of nitration: Novel nitroacetamidation of dienes

Solutions of nitronium tetrafluoroborate in acetonitrile prepared by anodic oxidation of nitrogen dioxide, efficiently nitrate aromatics, enolsilyethers, alkenes and conjugated dienes to afford respectively nitroaromatics, α-nitroketones, vicinal nitroamides and mixtures of nitroacetamides by 1,2- and 1,4-addition.     

Synthesis of HyBeacons and dual-labelled probes containing 2'-fluorescent groups for use in genetic analysis

An FMOC-protected 2'-hydroxyethyl uridine phosphoramidite has been used to synthesise fluorescein-labelled HyBeacon probes and "FAM-ROX" dual-labelled fluorogenic oligonucleotides.     

Zur Bestimmung und Trennung des Titans

Ohne Zusammenfassung     

Synthesis of tetracyclic hydrazones,hydrazo- and azo- compounds by reaction of hydrazine with 4,8-dimethylbicyclo[3,3,1]nona-3,7-diene-2,6-dione

4,8-Dimethylbicyclo [3,3,1]nona-3,7-diene-2,6-dione with hydrazine gives a tetracyclic bishydrazone having two double bonds at bridgehead positions; the chemistry of hydrazo-and azo- compounds derived from this bishydrazone is described.     

The effect of processing conditions on the u.v. stability of polyolefins

It is shown that the lifetime of polyolefins in the presence of u.v. light is markedly dependent on the degree of oxidation occurring during the prior processing operation. This is influenced strongly by the presence of pro-oxidants and anti-oxidants, and their effect on subsequent u.v. life can be rationalized on the basis of their functions during processing.