Simultaneous Determination of 8 Compounds in Gancao-Ganjiang-Tang by HPLC-DAD and Analysis of the Relations between Compatibility, Dosage, and Contents of Medicines

Table 4

Linear regression equation, linear range, LOD, and LOQ for eight standard substances.

Standard substance	Regression equation	Correlation coefficient ()	Linear range (μg/mL)	LOD (μg/mL)	LOQ (μg/mL)
Liquiritin		0.9998	18.5~296	1.52	4.56
Isoliquiritin		0.9999	7.9688~127.5	0.512	1.536
Liquiritigenin		0.9997	5.0625~81	0.477	1.431
Glycyrrhizic acid		0.9998	69.375~1110	2.561	7.683
Isoliquiritigenin		0.9997	0.9625~77	0.193	0.574
6-gingerol		0.9995	10.625~170	1.847	5.541
8-Gingerol		0.9997	5.4375~87	1.013	3.039
6-Shogaol		0.9996	0.75~96	0.132	0.396