title: Handling of environmental and biological samples via pre-column technologies.
abstract: Sample handling is still a weak point in chromatography and in analytical chemistry in general. One consideration is the automation potential of new procedures. Solid-liquid extraction techniques in combination with pre-column technology are particularly promising in this regards. The construction and geometry of pre-columns both for conventional and narrow-bore HPLC are of major importance, since band broadening should be kept at a minimum for an optimal functioning of the analytical system. The various operations that can be carried out with such a pre-column are trace-enrichment, clean-up of the sample which depends on the type of adsorbents used in the precolumn, i.e., polar or apolar materials, ion exchangers or metal covered surfaces, etc., protection of the analytical column, field sampling and storage of samples and as a substrate for on-column chemical derivatizations. These various operations are demonstrated with practical examples from the fields of environmental and biological analysis. The selectivity can be further enhanced by coupling pre-column technology with selective detection models such as diode array UV, electrochemical or fluorescence detection. This enables the construction of optimal and integrated analysis systems which are fully automated and microprocessor controlled. They can also be made compatible with miniaturized LC-technology.
mesh_terms: D001322:Autoanalysis; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D002845:Chromatography; D002851:Chromatography, High Pressure Liquid; D013048:Specimen Handling / Q000295:instrumentation / Q000592:standards*; D014131:Trace Elements / Q000032:analysis
chemical_list: D014131:Trace Elements