Flushing of an HPLC equipment

Flushing is certainly one of the best methods to prevent and to solve problems in HPLC. For most users a flushing step is simply part of a perfect gradient method. In isocratic elution, flushing is used at the end of a measurement series, to change to another method or merely when necessary, and is also advisable for economic reasons. Let s take a closer look at the symptoms that indicate the need to flush, what the underlying causes are and how best to flush. 

Note Some of the symptoms listed below (tailing, change of retention time) can also have other causes.. 

What are the causes and their symptoms (see within the parentheses). 

4 Memory effects, ghost peaks, negative peaks 

In order of efficiency methanol or acetonitrile, isopropanol (with the best flushing/efficiency ratio), CHCL, THF, hexane or heptane. As a last resort DMSO acidified with 0.1 % HCl 

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