[Influence of decoction methods and compatibility on content of cinnamaldehyde in Mahuang decoction]

To develop a GC-MS method for the determination of cinnamaldehyde and study on the influence of decoction methods and compatibility on the contents of cinnamaldehyde in Mahuang decoction.

Gas chromatography-mass spectrometry (GC-MS) was used. Chromatography/mass spectrometric conditions were: capillary column DB-17 (30 m x 0.5 mm, 0.25 micron), helium as carrier gas, non-split injection, column primary temperature 120 degrees C, 120 degrees C 8 degrees C/min-->250 degrees C, with 1.0 ml/min runoff, and injection volume 1 microliter. The results were analyzed by one-way ANOVA (SPSS).

The calibration curves were linear in the range from 0.0136 mg/ml to 0.136 mg/ml (r = 0.9999). The RSD of precison, stability and reproducibilities were 1.02% (n = 6), 2.57% in 24 h and 4.20%, respectively. The cinnamaldehyde content in the blended Mahuangtang decoction (BMHD) was significantly lower than the one in the separated and mixtured decoction and Ramulus cinnamomi decoction (P < 0.05). The separated and mixtured decoction was higher than Ramulus cinnamomi decoction (P > 0.05).

The main influencing factor of the cinnamaldehyde content was the compatibility. This method is precise and reliable to study cinnamaldehyde in Mahuang Decoction.