Micro-fluidic chip and its preparation and uses

The invention relates to a micro fluidic chip, in particular to a micro fluidic chip and the preparation thereof as well as the application as a solid phase extraction column. The chip is formed by sealedly connecting an upper base chip and a lower base chip, wherein, the upper base chip is provided with a sample inlet, a sample outlet and a microchannel. The microchannel of the upper base chip is provided with a particle guide channel and the inlet of the particle guide channel; dam structures are respectively arranged between the inlet of the particle guide channel and the sample outlet andbetween the inlet of the particle guide channel and the sample outlet. The two dam structures form a double-cofferdam structure, and the microchannels between the two dam structures form a packed column bed channel. Moreover, the places of the lower base chip corresponding with the dam structures are respectively provided with microchannels, and apertures are reserved between the top surfaces of the dam structures and the microchannel of the lower base chip; wherein, the depth of the apertures is smaller than the depth of the microchannels in the upper base chip. The invention has the advantages of simple and quick production, perfect repeatability, extensive application range and good using effect.