Determination of borneol and menthol in Tongning gel by GC

To establish a GC method for the determination of borneol, isobornel and mentol in Tongning gel. The GC column was packed with 5% diphenyl and 95% dimenthyl polysiloxanc(30 m×0. 32 mm×0. 2 μm), and the split ratio and column temperature were 50 ∶1 and 88 °C, respectively. The results showed that borneol, isoborneol and menthol in Tongning gel were well-separated. The calibration curves were linear over the concentration ranger of 0. 116 9-1. 402 8mg/mL, 0. 107 8-1. 293 6mg/mL and 0. 112 7-1. 352 4 mg/mL for borneol, isoborneol and menthol, respectively. The average recoveries were 98. 02%(RSD=1. 76%), 100. 00%(RSD=1. 78%)and 101. 77%(RSD=1. 33%)respectively. The established method is accurate, sensitive and reproducible in the quality control of Tongning gel.