Dilute and Shoot or Pre-treat the Sample

But sometimes more may be needed, either to protect expensive columns or to make the sample detectable. It is possible that a single injection of the wrong sample can destroy a column through contamination or plugging. Or perhaps a sample component must be enhanced to increase the concentration to a detectable level. Sometimes more is needed than just dilute and shoot . This chapter describes the various sample pretreatment methods, why they are used and where they are used. 

Sample pretreatment methods can be classified depending on need or effect  

Remove column contaminating material or particulate with a guard column. 

Enhance or enrich the concentration to improve the detection limit. 

Make the sample detectable by a process that collects the sample or converts the sample to a detectable form. 

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