A method of extracting an analyte from a solution comprising the steps of a. Providing an extraction column comprising a column body comprising a pipette tip having an open upper end, an open lower end, and an open channel between the upper and lower end of the column body; a bottom frit bonded to the column body and extending across the open channel; a top frit bonded to the column and extending across the open channel between the bottom frit and the open upper end of the column body , wherein the top frit, bottom frit, and column body define an extraction media chamber ; and a bed of extraction media positioned inside the extraction media chamber , wherein the extraction media comprises agarose, sepharose or cellulose gel resin beads, b. Passing a sample containing an analyte through the extraction column and c. Eluting the analyte by passing a desorption solvent through the extraction column, wherein the bed of extraction media in the extraction column has a volume in the range between 0.1 and 100 μL; characterized in that said column, which provides for an appoximately linear relationship between backpressure and flow rate, has been adapted to provide a back pressure in the range of about 3,45 kPa (0.5 psi) to 13,79 kPa (2 psi) when an aqueous solution is passed through the column at a flow rate of 1 mL/min; and that the sample solution in step b. is passed back and forth through the bed of extraction media more than one time. a. Providing an extraction column comprising a column body comprising a pipette tip having an open upper end, an open lower end, and an open channel between the upper and lower end of the column body; a bottom frit bonded to the column body and extending across the open channel; a top frit bonded to the column and extending across the open channel between the bottom frit and the open upper end of the column body , wherein the top frit, bottom frit, and column body define an extraction media chamber ; and a bed of extraction media positioned inside the extraction media chamber , wherein the extraction media comprises agarose, sepharose or cellulose gel resin beads, b. Passing a sample containing an analyte through the extraction column and c. Eluting the analyte by passing a desorption solvent through the extraction column, wherein the bed of extraction media in the extraction column has a volume in the range between 0.1 and 100 μL; characterized in that said column, which provides for an appoximately linear relationship between backpressure and flow rate, has been adapted to provide a back pressure in the range of about 3,45 kPa (0.5 psi) to 13,79 kPa (2 psi) when an aqueous solution is passed through the column at a flow rate of 1 mL/min; and that the sample solution in step b. is passed back and forth through the bed of extraction media more than one time. wherein the bed of extraction media in the extraction column has a volume in the range between 0.1 and 100 μL; characterized in that said column, which provides for an appoximately linear relationship between backpressure and flow rate, has been adapted to provide a back pressure in the range of about 3,45 kPa (0.5 psi) to 13,79 kPa (2 psi) when an aqueous solution is passed through the column at a flow rate of 1 mL/min; and that the sample solution in step b. is passed back and forth through the bed of extraction media more than one time. <EOS>