Table 5.

Stability of TSG, EDG, and emodin under various storage conditions.

Compound	concentration (ng/mL)	Long-term (-20°C)		Freeze–thaw		Short-term(24 h)
		Found concentration (ng/mL)	Accuracy (%)	Found concentration (ng/mL)	Accuracy (%)	Found concentration (ng/mL)	Accuracy (%)
TSG	5	4.73 ± 0.57	94.62 ± 11.38	5.02 ± 0.35	100.36 ± 7.04	4.87 ± 0.23	97.30 ± 4.66
	50	50.21 ± 4.66	100.42 ± 9.32	48.26 ± 6.09	96.52 ± 12.19	48.60 ± 4.72	97.21 ± 9.45
	500	533.15 ± 14.76	106.63 ± 2.95	541.11 ± 15.01	108.22 ± 3.00	548.65 ± 8.12	109.73 ± 1.62
EDG	5	4.80 ± 0.46	96.01 ± 9.22	4.81 ± 0.26	96.18 ± 5.23	4.70 ± 0.49	94.10 ± 9.90
	50	51.79 ± 4.02	103.58 ± 8.04	52.62 ± 4.32	105.24 ± 8.64	53.22 ± 4.34	106.43 ± 8.67
	500	502.26 ± 13.10	100.45 ± 2.62	513.72 ± 35.11	102.74 ± 7.02	517.46 ± 28.98	103.49 ± 5.80
Emodin	5	5.26 ± 0.46	105.26 ± 9.19	5.21 ± 0.24	104.25 ± 4.70	5.22 ± 0.56	104.49 ± 11.14
	50	53.46 ± 2.91	106.92 ± 5.82	54.71 ± 2.20	109.43 ± 4.40	53.29 ± 3.91	106.57 ± 7.83
	500	506.47 ± 38.44	101.29 ± 7.69	511.95 ± 54.80	102.39 ± 10.96	525.17 ± 39.13	105.03 ± 7.83

The data are represented as the mean ± SD, n = 6.