Determination of (-)menthone and menthol in Coughpill by GC

OBJECTIVE To establish a method for the determination of (-)menthone and menthol in coughpill. METHODS The analysis was carried out on an HP-FFAP capillary column(25 m×0.2 mm, 0.3 µm). Column temperature was at 90 ℃(2 min), 6 ℃·min^-1→150 ℃, 30 ℃·min^-1→220 ℃(4 min).Carrier was N2. Detector was FID. Temperature of the column entrance was 230 ℃. Temperature of the detector was 250 ℃. Fractional flow ratio was 10∶1. Sample quantity was 1.0 μL. RESULTS The linear range of (-)menthone was 0.044 86-0.897 2 mg·mL^-1(r=0.999 7). The average recovery was 98.12%, RSD=0.86%. The linear range of menthol was 0.064 88-0.973 2 mg·mL^-1(r=0.999 8). The average recovery was 100.91%, RSD=1.16%. CONCLUSION This method is simple, quick, accurate and reliable for the quality control of coughpill.