Simultaneous Quantification of Aspirin, Its Metabolite Salicylic Acid, and Salvianolic Acid B in Human Plasma Using UPLC-MS/MS

Table 4

Accuracy and precision of Sal B, ASA, and SA.

Nominal conc. (ng/mL)	Intraday (n = 6)			Interday (n = 18)
	Observed conc. (ng/mL)	Precision RSD (%)	Accuracy (RE%)	Observed conc. (ng/mL)	Precision RSD (%)	Accuracy (RE%)
Sal B
5	4.89 ± 0.26	5.31	−2.2	4.94 ± 0.37	7.56	−1.2
15	14.5 ± 0.5	3.44	−3.3	15.1 ± 0.8	5.01	0.6
3000	2802 ± 106	3.77	−6.6	2746 ± 108	3.92	−8.5
4500	4108 ± 99	2.42	−8.7	4333 ± 237	5.46	−3.7
ASA
5	4.80 ± 0.28	5.85	−4	4.96 ± 0.42	8.54	−0.8
15	14.8 ± 0.9	6.19	−1.3	14.4 ± 0.8	5.48	−4
3000	3037 ± 111	3.67	1.2	3157 ± 147	4.55	5.2
4500	4332 ± 140	3.22	−3.7	4184 ± 196	4.70	−7
SA
5	5.38 ± 0.46	8.52	7.6	5.14 ± 0.49	9.59	2.8
15	15.8 ± 0.8	5.26	5.3	15.7 ± 1.0	6.29	4.6
3000	2663 ± 82	3.09	−11	2734 ± 134	4.90	−8.9
4500	4257 ± 98	2.30	−5.4	4291 ± 199	4.64	−4.6

RSD% = (standard deviation/mean) × 100%. RE% = (mean of observed conc. − nominal conc.)/nominal conc. × 100%.