A method and apparatus for practicing solid phase extraction of samples for analysis where the method comprises the steps of providing a cassette having a plurality of tubes, each containing an absorbent substrate and having an upper and a lower opening; applying a preconditioning liquid reagent to each...http://www.google.fr/patents/US5260028?utm_source=gb-gplus-shareBrevet US5260028 - Method and apparatus for effecting solid phase extraction
Method and apparatus for effecting solid phase extraction
