Table 2.

Extraction replicates of the four analytes.

Compound	Origin amount/ng	Addition amount/ng	Measured amount/ng	Recovery rate (%)	Average recovery rate (%) (RSD%)
Epiberberine	50	25.0	74.3	97.2	98.5 (2.3)
	50	25.0	74.8	99.2
	50	25.0	75.3	101.2
	50	25.0	73.8	95.2
	50	25.0	74.1	96.4
	50	25.0	75.5	102.0
Coptisine	35	17.5	52.4	99.4	98.0 (2.04)
	35	17.5	51.8	96.0
	35	17.5	52.3	98.9
	35	17.5	51.5	94.3
	35	17.5	52.8	101.7
	35	17.5	52.1	97.7
Palmatine	55	27.5	81.1	94.9	96.2 (1.51)
	55	27.5	81.6	96.7
	55	27.5	82.1	98.5
	55	27.5	81.9	97.8
	55	27.5	80.8	93.8
	55	27.5	81.3	96.7
Berberine	35	17.5	51.9	96.5	97.1 (0.98)
	35	17.5	52.1	97.7
	35	17.5	51.7	95.4
	35	17.5	52.1	97.7
	35	17.5	51.9	96.6
	35	17.5	52.3	98.8