Table 2

Regression equation, correlation coefficients, linearity ranges and limit of detection and quantitation for the markers of Gegen Tang granule
Compounds
 Regression equation
 Linear range (μg/mL)
 R2
 LOD (ng/mL)
 LOQ (ng/mL)
 Intra-day RSD% (n = 6)
 Inter-day RSD% (n = 3)
Puerarin
 y = 40149x – 5483
 1.70 – 69.70
 0.9997
 6.21
 20.70
 0.83
 0.78
Paeoniflorin
 y = 13018x + 3168
 1.07 – 64.36
 0.9996
 19.64
 65.46
 0.99
 0.45
Cinnamic acid
 y = 68413x + 2472
 0.15 – 5.81
 0.9998
 3.72
 12.40
 0.61
 0.60
Daidzain
 y = 44698x + 350
 0.06 – 4.96
 0.9997
 5.58
 18.60
 0.33
 1.83
Glycyrrhizin
 y = 5695x – 3089
 1.07 – 85.26
 0.9998
 45.47
 151.56
 0.10
 1.70
Ephedrine
 y = 21411x +1949
 1.08 – 86.13
 0.9998
 3.82
 12.73
 0.52
 1.55
Pseudoephedrine
 y = 30269x – 41321
 2.98 – 119.13
 0.9996
 2.71
 9.03
 0.37
 0.41

All regression results are statistically significant (P < 0.05)

Song et al. Chinese Medicine 2007 2:7   doi:10.1186/1749-8546-2-7