Abstract: Sample preparation is very important in the chromatographic analysis due to its time consumed and deviations produced, therefore the problem of on-line sample preparation techniques is the front project in the field of analytical chemistry. In this paper, the progress of on-line sample preparation techniques in chromatographic analysis, including solid phase extraction, solid phase microextraction, liquid phase microextraction, membrane assisted extraction, field assisted extraction, gas phase extraction, thermal desorption and microfluidic chip is reviewed.

Key words: chromatographic analysis, review , on-line sample preparation