Determining the Levels of Four Phenylethanoid Glycosides and Five Triterpene Acids in Liuwei Dihuang Capsule Using Solid Phase Extraction with HPLC-UV

Table 1

Recoveries of the four phenylethanoid glycosides and five triterpene acids from spiked samples using different SPE cartridges.

Compound	Recovery ± SD^α (%)
	C18	Alumina-N	HLB	PSA	P-SAX
Purpureaside C	91.7 ± 0.5	19.5 ± 2.8	96.7 ± 2.2	64.0 ± 2.7
Jionoside A1	92.2 ± 0.6	24.8 ± 4.1	97.3 ± 1.7	65.2 ± 2.3
Acteoside	95.5 ± 1.2	12.4 ± 3.1	90.4 ± 0.4	88.6 ± 0.4
Isoacteoside	90.3 ± 0.8	22.1 ± 3.3	93.6 ± 1.1	81.7 ± 1.8
3-O-Acetyl 16α-hydroxytrametenolic acid	91.8 ± 0.2	15.6 ± 3.2	92.2 ± 2.5		62.0 ± 2.3
Dehydropachymic acid	96.6 ± 0.3	64.5 ± 2.4	96.8 ± 0.7		ND^b
Pachymic acid	97.8 ± 1.5	71.3 ± 2.1	90.6 ± 1.7		70.3 ± 0.9
Trametenolic acid	95.2 ± 0.6	56.1 ± 2.1	93.5 ± 2.1		88.6 ± 0.8
Dehydrotrametenolic acid	94.5 ± 1.2	66.3 ± 2.2	90.2 ± 1.4		85.7 ± 1.5

^αStandard deviation, n = 3. ^bBelow the detection limit.