High temperature injection in capillary high temperature liquid chromatography

Summary

A new high temperature sample introduction device for use in packed capillary high temperature liquid chromatography has been developed. In combination with a commercially available high temperature injection valve, samples with little solubility in any solvent at ambient temperature could be analyzed. Injections of synthetic high molecular weight hydrocarbon waxes were feasible at elevated temperatures with the high temperature sample introduction device. Compared to injection with a preheated conventional HPLC syringe, problems of precipitation and plugging were removed, the injection time was reduced and the relative standard deviation of area measurements was improved. The synthetic waxes could be separated with temperature programming and isocratic mobile phases, with packed capillary columns and evaporative light scattering detection. Key words: liquid chromatography; packed capillary columns; high temperature injection; temperature programming; hydrocarbon waxes