Objective: To investigate effect of compatibility on alkaloids in Aconiti Radix Cocta from Wutou Tang. Method: HPLC-ESI-MS positive ion mode was adopted to analyze alkaloids in Aconiti Radix Cocta single decoction and Wutou Tang

parsing each component of MS2 and MS3 spectra

thus comparing alkaloids between Aconiti Radix Cocta single decoction and Wutou Tang. Result: Thirty-six common compositions were detected in Aconiti Radix Cocta single decoction and Wutou Tang

13 ingredients were detected in single decoction

which were not detected in Wutou Tang

such as dehydrared 10-OH-aconitine

dehydrated 10-OH-aconine

mesaconitine and so on. 10-OH-mesaconine in Wutou Tang was not detected in single decoction solution of Aconiti Radix Cocta. Conclusion: A lot of aconitine type alkaloids in Aconiti Radix Cocta are missing after compatibility

ingredients are clearly different.This established HPLC-ESI-MS can effectively separate various aconitine type alkaloids by providing molecular weight and structure information of components.