Isotachophoresis (ITP) was applied for the determination of some antirheuma
tic drugs (fenoprofen, naproxen, ibuprofen, and ketoprofen) in human serum.
The leading electrolyte contained hydrochloric acid (10 mmol.L-1), creatin
ine (pH 4.5) and methylhydroxyethyl cellulose (0.1%). The terminating elect
rolyte was 2-(N-morpholino)ethanesulfonic acid (10 mmol.L-1) adjusted with
tris(hydroxymethyl)aminomethane to pH 6.9. The ITP separations were carried
out in column-coupling configuration of the separation unit provided with
a preseparation column of 160 x 0.8 mm inner diameter. (ID) and analytical
column of 160 x 0.3 mm ID. The limit of detection for ibuprofen, fenoprofen
, and naproxen in serum by direct sampling was 0.008, 0.005 and 0.004 mmol.
L-1. The limit of detection for ketoprofen in serum after ethanol precipita
tion was 0.001 mol.L-1.