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

Table 3

Contents of (R)- and (S)-goitrin in 9 batches of Banlangen granules ().

Sample	(R)-Goitrin; (mg/g)	Standard deviation; (mg/g)	(S)-Goitrin; (mg/g)	Standard deviation; (mg/g)	R/S ratio
A1	0.071	0.0009	0.037	0.0005	1.93
A2	0.247	0.0040	0.174	0.0026	1.42
A3	0.209	0.0019	0.183	0.0018	1.14
A4	0.494	0.0114	0.429	0.0090	1.15
A5	0.272	0.0044	0.199	0.0034	1.37
A6	0.079	0.0008	0.056	0.0005	1.41
B1	0.024	0.0002	0.018	0.0001	1.30
B2	0.026	0.0002	0.020	0.0002	1.33
B3	0.039	0.0004	0.030	0.0003	1.30
Mean	0.162		0.127		1.37
RSD (%)	97.4		106.8		17.0