The main components of a common cold medicine includes acetoaminophen, anhydrous caffeine, hesperidine, ethenzamide, tipepidine hibenzate, and apronalid. We examined the applicability of an X-Press Pak C18S column (2.1 mm .I.D. x 50 mmL.) packed with 2 µm diameter packing material for the ultra-high speed separation of the above medicines. The results were examined to determine whether the performance of the column and chromatography separation exceeds that of conventional HPLC.
LC-4000 UHPLC system
Column: X-PressPak C18S (2.1 mm I.D. x 50 mm L.)
Column temperature: 40 ºC
Mobile phase: methanol/0.1% phosphoric acid (40/60)
Flow rate: 0.5 mL/min
Detection: UV detection (wavelength: 260 nm)
Injection volume: 1 µL
Figure 1 shows the separation of a standard mixture including acetoaminophen (0.02 mg / mL), anhydrous caffeine (0.02 mg / mL), phenol (for internal standard, 0.02 mg/mL), hesperidine (0.02 mg/mL), ethenzamide (0.02 mg/mL), tipepidine hibenzate(0.02 mg/mL) and apronalid (0.1 mg/mL). Our UHPLC system provides an analysis time 6 times faster than conventional HPLC without sacrificing the resolution between each peak.
Figure1. Chromatogram of a standardmixture of components of cold medicines (Peaks: 1 = acetoaminophen (0.02 mg/mL), 2 = anhydrous caffeine (0.02 mg/mL), 3 = phenol (internal standard, 0.02 mg/mL), 4 = hesperidin (0.02 mg/mL), 5 = ethenzamide (0.02 mg/mL), 6 = tipepidine hibenzate (0.02mg/mL), and 7 = apronalid(0.1mg/mL))