The invention belongs to the field of detection technology of
levofloxacin, and discloses a quantitative detection method of
levofloxacin in
plasma. The method comprises the following steps: weighinglevofloxacin reference substance and
levofloxacin-d8, diluting the levofloxacin reference substance and the levofloxacin-d8 with
methanol and a
methanol aqueous solution to obtain a series of levofloxacin working solutions and
internal standard working solutions; pretreating a
plasma sample by using the
internal standard working solutions and a
methanol precipitant, and performing LC-MS /
MS analysis; preparing a series of correction guide samples and accompanying
quality control samples by using blank
plasma and the series of levofloxacin working solutions, then respectively performing LC-MS / MSmeasurement, using a chromatographic
peak area ratio of the levofloxacin and the
internal standard levofloxacin-d8 as a
vertical coordinate, using the concentration of levofloxacin in the plasma as an abscissa to make a
standard curve, and calculating the concentration of the levofloxacin in the
plasma sample. The quantitative detection method disclosed by the invention has the advantages that measurement is performed via
precipitation pretreatment and an LC-MS / MS
mass spectrometer, so that the operation is quick and simple, the separation effect is good, the qualitative determination is accurate, and the detection sensitivity is high.