Online Heart-Cutting Liquid Chromatographic Analysis of Linezolid in Human Serum

Abstract

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. 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 mu g/mL was found as linear calibration curve. 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.