Cloud-Point Extraction Combined with Liquid Chromatography for the Determination of Ergosterol, a Natural Product with Diuretic Activity, in Rat Plasma, Urine, and Faeces

Table 3

Summary of stability studies of ergosterol in rat plasma, urine, and faeces under various storage conditions.

Biological matrix	Added concentration (𝜇g/mL)	Found concentration (𝜇g/mL)	Recovery (%)	RSD %
	Short-term stability
	0.25	0.249±0.010	99.6	4.1
Plasma	0.75	0.714±0.043	95.2	6.7
	2.00	1.90±0.080	95.0	1.9
	0.25	0.252±0.011	100.8	4.6
Urine	0.75	0.717±0.039	95.6	1.4
	2.00	1.91±0.01	95.5	1.6
	0.25	0.243±0.007	97.2	2.9
Faeces	25	24.8±0.63	98.8	2.5
	100	99.4±2.1		2.1
	Three freeze-thaw cycles
	0.25	0.262±0.021	104.8	7.8
Plasma	0.75	0.738±0.027	98.4	4.2
	2.00	1.92±0.08	96.0	2.1
	0.25	0.251±0.011	100.4	4.6
Urine	0.75	0.759±0.032	101.2	3.5
	2.00	1.93±0.04	96.5	2.2
	0.25	0.251±0.007	100.4	3.2
Faeces	25	24.7±0.6	98.8	2.6
	100	98.9±3.3	98.9	3.3
	Long-term stability
	0.25	0.250±0.013	100.0	4.6
Plasma	0.75	0.723±0.045	96.4	2.9
	2.00	1.95±0.12	97.5	1.8
	0.25	0.238±0.009	95.2	4.0
Urine	0.75	0.759±0.007	101.2	3.1
	2.00	2.06±0.15	103.0	5.2
	0.25	0.249±0.011	99.6	4.5
Faeces	25	24.6±0.5	98.4	2.1
	100	100.1±2.4	100.1	2.4