Stereospecific Assay of (R)- and (S)-Goitrin in Commercial Formulation of Radix Isatidis by Reversed Phase High-Performance Liquid Chromatography

Table 2

Linearity, LOD, LOQ, precision, repeatability, and recovery of the RPLC separation method.

	S-Goitrin			R-Goitrin
Linearity range (μg/mL)	0.08, 0.4, 2, 8, 40			0.1, 0.6, 3, 12, 60
LOD (ng/mL)	2.0			2.9
LOQ (ng/mL)	81.9			118.0
Precision
Concentration level (μg/mL)	0.08	2	40	0.1	3	60
Intraday (, RSD, %)	0.6	0.3	0.7	0.6	0.8	1.1
Interday (, RSD, %)	0.9	0.5	1.0	1.3	0.5	0.4
Repeatability (, RSD, %)	2.1			2.6
Recovery
Mean (%)	100.1			99.4
RSD (, %)	0.5			0.3