Objective:

2

To establish a pre-column derivatization reverse-phase high-performance liquid chromatography (RP-HPLC) method for the simultaneous determination of 17 amino acids in Cynomorii Herba from different producing areas and conduct a multivariate statistical analysis.

Method:

2

RP-HPLC with pre-column derivatization was employed

with phenyl isothiocyanate (PITC) as derivatization reagent. Separation was performed on a WondaSil C

18

-WR column (4.6 mm×150 mm

5 μm)

with 0.05 mol·L

-1

sodium acetate solution (pH 6.5) as mobile phase A

and acetonitrile-methanol-water (3∶1∶1) as mobile phase B for gradient elution at a flow rate of 0.8 mL·min

-1

. The detective wave length was set at 254 nm

and the column temperature was maintained at 35 ℃. Principal component analysis (PCA) and systematic cluster analysis (HCA) models were established for multivariate statistical analysis and quality evaluation.

Result:

2

17 Kinds of amino acid were detected in Cynomorii Herba

7 of which were essential amino acids. The 17 amino acids showed good linearity in respective concentration range

r

= 0.999 0-0.999 9.The average recoveries were between 98.03%-103.89%with RSD

<

3.5%. The results of PCA and HCA were basically the same

and both methods can be used to clearly distinguish Cynomorii Herba from 12 municipal producing areas into 6 regions. PCA can be used to classify Cynomorii Herba according to different municipal or provincial production areas

and HCA can be used to classify it according to provincial production areas. It showed that the amino acid contents in Cynomorii Herba from different municipal and provincial producing areas had differences

and the content distribution showed obvious geographical clustering characteristics. PCA showed that Cynomorii Herba from Gansu province and Inner Mongolia had higher amino acid contents and better quality as compared with other producing areas.

Conclusion:

2

The established method can be used for content determination of 17 amino acids in Cynomorii Herba from different producing areas

and provide a reference for its comprehensive quality evaluation.