Table 3.

Coefficient of determination, accuracy, limit of detection (LOD), and limit of quantification (LOQ) of 23 targeted PDE5 inhibitors.

No.	Analytes	Coefficient of determination (r2)	Accuracy (Mean ± SD, %) (n = 3)			LOD (ng/mL)	LOQ (ng/mL)
			Low	Med	High
1	Desmethylcarbodenafil	0.9979	116.5 ± 3.4	102.9 ± 1.9	108.8 ± 2.2	10	80
2	Carbodenafil	0.9982	119.3 ± 1.1	100.4 ± 2.8	107.8 ± 1.6	10	80
3	N-desethylacetildenafil	0.9980	105.8 ± 2.5	96.6 ± 4.1	104.1 ± 2.8	30	80
4	Acetildenafil	0.9969	106.3 ± 0.4	106.8 ± 6.4	100.6 ± 1.7	20	80
5	Hydroxyvardenafil	0.9985	103.5 ± 2.2	108.8 ± 3.2	108.6 ± 1.5	10	80
6	Dimethylacetildenafil	0.9960	117.5 ± 3.0	94.8 ± 3.8	109.2 ± 1.9	20	80
7	Vardenafil	0.9972	94.8 ± 1.2	110.3 ± 1.4	107.0 ± 1.2	20	80
8	Sildenafil	0.9989	110.9 ± 1.3	101.0 ± 1.6	109.3 ± 1.5	30	80
9	Homosildenafil	0.9993	108.3 ± 1.0	105.8 ± 1.1	107.3 ± 1.2	40	80
10	Dimethylsildenafil	0.9989	116.5 ± 0.8	103.5 ± 1.2	107.7 ± 0.8	30	80
11	Propoxyphenyl-hydroxyhomosildenafil	0.9984	116.8 ± 3.6	103.2 ± 1.4	107.9 ± 2.4	70	80
12	Udenafil	0.9994	109.2 ± 1.9	105.8 ± 1.2	108.0 ± 1.4	10	80
13	Propoxyphenyl-sildenafil	0.9988	106.2 ± 1.0	107.4 ± 2.4	107.3 ± 1.6	10	80
14	Hydroxythiovardenafil	0.9984	98.5 ± 1.6	107.8 ± 1.0	107.5 ± 0.7	20	80
15	Tadalafil	0.9983	119.2 ± 4.4	106.5 ± 1.8	107.0 ± 3.1	60	80
16	Mirodenafil	0.9963	117.3 ± 1.4	101.6 ± 2.4	106.5 ± 0.7	10	80
17	Mutaprodenafil	0.9977	88.1 ± 1.6	108.4 ± 1.6	107.3 ± 1.4	20	80
18	Thiosildenafil	0.9972	97.5 ± 1.9	109.0 ± 1.6	107.6 ± 1.4	30	80
19	Thiohomosildenafil	0.9972	97.5 ± 1.5	109.6 ± 1.7	106.9 ± 1.9	10	80
20	Dithiodesmethylcarbodenafil	0.9960	90.7 ± 2.5	109.9 ± 1.3	106.7 ± 2.0	10	80
21	Thiodimethylsildenafil	0.9992	107.4 ± 2.2	105.2 ± 2.1	106.8 ± 0.8	20	80
22	Propoxyphenyl-thiohydroxyhomosildenafil	0.9986	104.3 ± 2.8	109.2 ± 1.2	108.4 ± 0.6	20	80
23	Propoxyphenyl-thiodimethylsildenafil	0.9989	106.9 ± 4.9	105.1 ± 1.6	108.6 ± 1.2	10	80