Liquid-chromatographic quantification compared with gas-chromatographic-mass-spectrometric determination of XXXX and @entity55428 in plasma.

@entity4315 @entity1855 @entity1626 @entity23052 @entity1391 @entity15 @entity55428
A high-performance liquid chromatographic (HPLC) method for determining @entity1855 and @entity55428 in plasma is presented and compared with gas chromatography/mass spectrometry (GC- @entity15 ). The plasma samples were extracted at alkaline pH with @entity4315 containing @entity23052 (20 mL/L) and then back-extracted into @entity1391 buffer (0.1 mol/L, pH 3.0). For chromatography we used a reversed-phase column (Supelcosil LC-18 DB) with a mobile phase of the @entity1391 buffer and @entity1626 (70/30 by vol). Fluorescence detection was used (excitation at 203 nm, emission at 320 nm). Overall analytical recovery was 85%. Standard curves were linear from 1 to 1000 micrograms/L. The detection limit was 1 microgram/L. The assays are accurate and precise. We found no interferences by those substances tested. Results by HPLC and GC- @entity15 agreed well (r = 0.99) for both @entity1855 and @entity55428 determinations.
