HPLC system contamination minimizing

HPLC is a method for the analysis and characterization of steroid receptors based on characteristics such as molecular weight. Qualitative relationships and multiple forms of the receptor can be maintained by the rapid gel-exclusion system, and contaminants can be readily identified (P2). Advantages of using HPLC include rapid analysis time, minimal receptor modification, improved resolution, and high reproducibility. Unfortunately the HPLC assay is tedious, requiring saturation analysis for each sample and quantitative validity has not been established for this procedure. Other disadvantages associated with HPLC methods include the requirement for expensive equipment and sophisticated technical skills. Therefore, HPLC analysis of receptor proteins is currently used only in research studies. 

HPLC not only provides a very good cleanup of the sample performing separation of PCBs from other similar organic compounds such as polycyclic aromatic hydrocarbons (PAHs), but it also allows the separation of coplanar non-ortho substituted PCBs. Coupling of the extraction system with an online LC-GC system allows the whole analysis to be done in a closed system, minimizing the risk of sample contamination or loss of analytes. Moreover, automating the cleanup procedure may reduce the time of analysis and increase overall reproducibility. 

Column-switching techniques have been used to analyze a sample directly, without any pretreatment stages, with the advantage of easy automation. The increase in safety and the improved analytical speed and accuracy often make up for the initial cost of the additional equipment that is required. Automating the column-switching systems can usually be accomplished using the timed-event tables included with HPLC instrument-control software this enables a simpler and a more accurate control of complex column networks with minimal contamination and loss. 

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