. A sample volume, from 1 to 50 mL, was adjusted
to pH 3 by the addition of 100 mM ammonium formate in water
(ratio sample-buffer 10:1 v/v) and loaded through the MIP cartridge
at an approximate speed of 2 mL min−1 using a SPE vacuum manifold.
Cartridge was washed with 1 mL deionized water and 1 mL
40% (v/v) acetonitrile in water