Determination of 14 Anti-Aging and Hair Growth Drugs in Shampoo by Ultra-High Performance Liquid Chromatography Tandem Mass Spectrometry

A method for the determination of 14 anti-aging and hair growth drugs including cimetidine, minoxidil, melatonin, methyl vanillate, ketoconazole, bimatoprost, finasteride, setipiprant, nilutamide, fluridil, spironolactone, flutamide, latanoprost and dutasteride in shampoo by ultra-high performance liquid chromatography-tandem mass spectrometry was proposed. The sample was dissolved in water, extracted with acetonitrile, and purified with amino solid phase extraction column. Gradient elution was performed using Waters Accquity UPLC BEH C₁₈ column as the stationary phase and acetonitrile-2 mmol·L^-1 ammonium acetate solution containing 0.1% (volume fraction) formic acid as the mobile phase system. The 14 separated targets were scanned by electrospray ion source with positive and negative ion modes and detected by multi-reaction monitoring mode. It was shown that linear relationships between the mass concentrations and corresponding peak areas of 14 targets were kept in the range of 1.0-50.0 μg·L^-1, with detection limits (3S/N) in the range of 0.05-3.0 μg·kg^-1. Test for recovery was made on the blank sample at 3 concentration levels by standard addition method, giving results in the range of 83.6%-99.0%, and RSDs (n=6) of determined values ranged from 5.6% to 15%. The method was applied to the analysis of 10 shampoo samples. Minoxidil, cimetidine, setipiprant, ketoconazole, nilutamide and fluridil were detected in one sample, and melatonin was detected in another sample, with detection amounts in the range of 0.4-47.8 μg·kg^-1.