Determination of linezolid in human breast milk by high-performance liquid chromatography with ultraviolet detection

J AOAC Int. 2009 Nov-Dec;92(6):1658-62.


A rapid and simple HPLC method was developed for the determination of linezolid (LNZ) in human breast milk after a simple protein precipitation with methanol. The chromatographic separation was achieved on a C18 column (5 microm, 250 x 4.6 mm id) using a mobile phase of acetonitrile-10 mM acetic acid (25:75, v/v) at a flow rate of 1 mL/min. The LNZ peak was measured by photodiode array detection at 250 nm. The calibration graph was linear over the range of 0.5-20.0 microg/mL. The limits of detection and quantitation were found to be 0.1 and 0.5 microg/mL, respectively. The precision of the assay and the recovery of LNZ from breast milk at three different concentrations were assessed. The intraday and interday RSD values were found to be < 5%. The mean absolute recovery was 85.33%. The developed method was successfully applied to the determination of LNZ in breast milk obtained from the breastfeeding mother after oral administration of LNZ.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetamides / analysis*
  • Anti-Bacterial Agents / analysis*
  • Chromatography, High Pressure Liquid
  • Female
  • Freezing
  • Humans
  • Indicators and Reagents
  • Linezolid
  • Milk, Human / chemistry*
  • Oxazolidinones / analysis*
  • Reference Standards
  • Reproducibility of Results
  • Solutions
  • Spectrophotometry, Ultraviolet


  • Acetamides
  • Anti-Bacterial Agents
  • Indicators and Reagents
  • Oxazolidinones
  • Solutions
  • Linezolid