Objective:

2

Based on the color space technology of CIE-LAB

the color of vinegar-processed Corydalis Rhizoma decoction pieces was digitized

combining with the contents of 10 major alkaloids in the decoction pieces

to discuss the correlation between the color and contents of main ingredients of vinegar-processed Corydalis Rhizoma decoction pieces

and investigate the intrinsic quality difference in the decoction pieces with different color.

Method:

2

The precision colorimeter was used to determine the color parameters of vinegar-processed Corydalis Rhizoma decoction pieces; HPLC was employed to determine contents of main chemical components in the decoction pieces

which was performed on Agilent ZORBAX SB-C

18

column(4.6 mm×250 mm

5 μm) with mobile phase of acetonitrile(A)-0.1% potassium dihydrogen phosphate aqueous solution(B) for gradient elution(0-10 min

5%-22%A; 10-30 min

22%-25%A; 30-50 min

25%-60%A; 50-70 min

60%-95%A)

detection wavelength of 280 nm

column temperature at 30 ℃ and flow rate of 1.0 mL·min

-1

.

Result:

2

The quality of vinegar-processed Corydalis Rhizoma decoction pieces with different color was in line with the requirement of the 2015 edition of

Chinese Pharmacopoeia

but there were differences in the intrinsic quality between the decoction pieces.The total content of chemical components in the samples showed a positive correlation with the

a

*

(green-red axis) and total chromatic aberration value(Δ

E

) in the CIE-LAB color space

and it was significantly negative correlated with

L

*

(lightness) and

b

*

(blue-yellow axis). In the 10 tested components

except for

D

-tetrahydrojatrorrhizine and tetrahydrocoptisine

contents of protopine and other 6 components were positively correlated with color

and only the content of corydaline was negatively correlated with color.

Conclusion:

2

Color analysis technology can objectively quantify the color of the decoction pieces

and can achieve a quick evaluation of quality of the decoction pieces by analyzing correlation between the color and the contents of main active ingredients.