TABLE 3.

Results of method validation

Compounds	1	2	3	4	5	6	7
Regression equation (y)	(3.80 × 107)x − 5.72 × 104	(2.35 × 108)x − 1.45 × 105	(1.14 × 109)x + 4.57 × 105	(754 × 107)x + 2.24 × 105	(5.06 × 108)x – 4.49 × 105	(9.76 × 108)x – 2.12 × 106	(1.75 × 109)x – 2.20 × 106
Correlation coefficient (R 2)	0.9992	0.9991	0.9979	0.998	0.9968	0.9994	0.9911
Linearity range (μg/mL)	0.56–1,227.50	0.53–127.86	0.15–108.88	0.49–1,080.00	0.50–366.08	0.15–965.46	0.17–40.74
LOD (μg/mL)	1.12	0.33	0.08	0.25	0.25	0.15	0.047
LOQ (μg/mL)	1.9	1.19	0.23	1.48	0.76	0.67	0.17
Precision (%)
Intraday	2.85	2.99	0.84	0.40	2.52	3.03	1.83
Interday	3.83	2.20	2.63	1.83	3.90	4.55	5.17
Accuracy (%)
High spike	102.3	96.6	n.d.	n.d.	n.d.	n.d.	n.d.
Medium spike	99.2	102.4	n.d.	n.d.	n.d.	n.d.	n.d.
Low spike	102.4	97.7	n.d.	n.d.	n.d.	n.d.	n.d.
Combined uncertainty U (%)	2.55	8.10	1.52	1.50	3.09	3.18	3.87
Expanded uncertainty Uexp (%) (k = 2)	5.09	16.20	3.04	2.99	6.17	6.36	7.75

LOD, limit of detection; LOQ, limit of quantitation; n.d., not determined.