A high performance liquid chromatography-tandem mass spectrometric(HPLC-MS/MS) method was established for the determination of bimatoprost in eyelash enhancing cosmetics serums.The samples were extracted with 50%(by vloume) methanol

then separated on an Agilent Poroshell 120 EC-C18(4.6 mm×100 mm

2.7 μm) column by isocratic elution

with 5 mmol·L-1 ammonium acetate containing 0.02% formic acid-acetonitrile(55∶45) as mobile phases at a flow rate of 0.3 mL·min-1.The analyte was detected by HPLC-MS/MS with electrospray ionization source in positive ion mode(ESI+) and multiple reaction monitoring(MRM)

and quantified by external standard method.Results showed that there existed a good linear relationship for bimatoprost in the range of 0.50-100 ng·mL-1 with a correlation coefficient(r2) of 0.998 2.The limit of detection(LOD

S/N=3) and limit of quantitation(LOQ

S/N=10) were 0.015 and 0.05 μg·g-1

respectively.The recoveries at low

medium and high spiked levels were 98.6%

101% and 99.2%

with relative standard deviations(RSDs) of 2.4%

2.1% and 1.2%

respectively.The method is simple

rapid and high sensitive

and is suitable for the rapid determination of bimatoprost in eyelash enhancing cosmetics serums.