Determination of Platycodin D and Platycodin D3 in Rat Plasma Using Liquid Chromatography-Tandem Mass Spectrometry

Table 4

Stability of PD in rat plasma (𝑛=5 at each level).

Conditions	Theoretical concentration; (ng/mL)	Final concentration; (ng/mL)	RE (%)	CV (%)
Three freeze/thaw cycles; (−70°C)	150	149.8	0.1	4.2
	1000	1005.3	0.5	3.7
	8000	7956.8	−0.5	3.2
Bench top stability; (room temp., 24 h)	150	147.9	−1.4	7.0
	1000	1053.5	5.4	5.2
	8000	8180.9	2.3	1.8
Postpreparative stability; (4°C, 24 h)	150	147.0	−2.0	6.2
	1000	927.1	−7.3	1.1
	8000	7479.3	−6.5	1.3
Long term stability; (−70°C, 1 week)	150	148.4	−1.1	5.5
	1000	973.9	−2.6	3.1
	8000	7425.3	−7.2	1.9
Long term stability; (−70°C, 2 weeks)	150	152.2	1.5	3.7
	1000	993.3	−0.7	6.1
	8000	7477.6	−6.5	3.6

CV: coefficient of variation; RE: relative error.