Patent ID: 7666686

Claim:
A method for sample preparation for analysis of liquid samples comprising: providing a solid phase extraction cartridge which comprises a first container having an inlet and an outlet, said first container containing a bed of a first sorbent; providing a gas filter which comprises a second container having an inlet, an outlet, and a luer fitting at said outlet, said second container containing a bed of a second sorbent; introducing a liquid sample comprising a solvent and one or more analytes into the solid phase extraction cartridge, such that the liquid sample is not passed through the bed of the second sorbent before being introduced into the solid phase extraction cartridge; adsorbing the one or more analytes onto the first sorbent and passing the solvent through the bed of the first sorbent; forming an essentially gastight connection between the inlet of the solid phase extraction cartridge and the outlet of the gas filter using an adapter so dimensioned as to form a tight fit to the inlet of the solid phase extraction cartridge and receive the luer fitting of the outlet of the gas filter; passing a gas through the gas filter and the solid phase extraction cartridge such that the gas passes through the bed of the second sorbent in the gas filter before passing through the bed of the first sorbent in the solid phase extraction cartridge to dry the bed of the first sorbent; introducing a second solvent into the solid phase extraction cartridge, such that the second solvent is not passed through the bed of the second sorbent before being introduced into the solid phase extraction cartridge; passing the second solvent through the dried bed of the first sorbent to elute the one or more analytes adsorbed to the first sorbent; and collecting the second solvent containing the one or more eluted analytes.