Introduction: In this assay, a selective, simplistic and sensitive new online heart-cutting Liquid
Chromatographic analysis method was developed for the quantification of linezolid in human serum. The
new method allows to the quantification of linezolid in serum without complicated sample preparation.
Materials and Methods: Before analysis, the samples were mixed with methanol and filtered. Separations
were carried out with following systems; 1st dimension is a system consisting of 2.1 x 50 mm Biphenyl
pre-separation column with acetonitrile and 0.03 M o-phosphoric acid solution mixture (15:85) as mobile
phase and the 2nd dimension is a system consisting of 4.6 x 150 mm Pentafluorophenyl propyl separating
column with acetonitrile and 0.03 M o-phosphoric acid solution mixture (25:75) as mobile phase. Two
systems were connected via a 6-port valve having 0.2 mL loop and separations were carried out continuously
during injections. For both systems, 250 nm has been selected as detection wavelength. The concentration
range of 0.5-20 µg/mL was found as linear calibration curve.
Conclusion: The new method was successfully applied for the quantification of linezolid in human serum
samples collected from a volunteer who has received 600 mg linezolid orally.