HPLC Retention Control of Antibiotics (Metronidazole and Norfloxacine) in Toothpaste

  Commercially available toothpaste has been known to include antibiotics. To demonstrate the retention control on the mixed-mode column Primesep 100, toothpaste was spiked with the antibiotics metronidazole and norfloxacin. In a 13 minute method, retention of the antibiotics was controlled by adjustment in ratio of organic in the mobile phase. This method demonstrates the flexibility of using mixed-mode columns such as Primesep 100.  


Column Primesep 100, 4.6x150 mm, 5 µm, 100A
Mobile Phase MeCN/H2O
Buffer H2SO4
Flow Rate 1.0 ml/min
Detection UV, 250 nm


Class of Compounds Drug, Antibiotics, Hydrophilic, Ionizable
Analyzing Compounds Metronidazole, Norfloxacine
Application Analytes: