Determination of 6 Kinds of Residual Organic Solvents in Tetrandrine by GC

OBJECTIVE To establish a capillary gas chromatography method for determination of six residual organic solvents including methanol, ethanol, acetone, trichloromethane, benzene and cyclohexane in tetrandrine. METHODS The determination was performed on a Rtx-1 capillary column(30 m×0.25 mm, 0.25 μm) with nitrogen gas as carrier and FID as detector. DMF was used as solvents. The initial column temperature was 30 ℃, maintaining for 7.5 min, then raising the temperature to 35 ℃ at the rate of 5 ℃·min^-1 and maintaining for 11.5 min, then raising the temperature to 200 ℃ at the rate of 40 ℃·min^-1 and maintaining for 10 min. RESULTS The six residual solvents showed good linearity (r=0.998 7-0.999 9) in the experimental concentration ranges. The average recovery rates of the preparation were in the range of 99.6%-105.9%. The detection limits were 0.30, 0.22, 0.16, 0.88, 0.03, 0.10 μg·mL^-1. CONCLUSION The method is simple, sensitive, accurate, and suitable for the determination of the residual organic solvents in tetrandrine.