Tab. 3.

Robustness evaluation^a of the method (n=6)

		Retention time (tR)			Asymmetry (T)
Factor	Level	ACF	PCM	TRM	ACF	PCM	TRM
Flow Rate (mL min−1)
0.9	−1	15.336	3.316	7.958	1.27	1.22	1.01
1.0	0	14.648	3.137	7.850	1.27	1.22	1.02
1.1	+1	13.950	2.972	7.768	1.26	1.23	1.00
Mean ± S.D.		14.645	3.142	7.859	1.27	1.22	1.01
		± 0.69	± 0.17	± 0.10	± 0.01	± 0.01	± 0.01
Percentage of methanol in the mobile phase (v/v)
59	−1	15.213	3.156	7.923	1.29	1.17	1.03
60	0	14.648	3.137	7.850	1.27	1.22	1.02
61	+1	14.186	3.092	7.762	1.27	1.21	1.02
Mean ± S.D.		14.682	3.128	7.845	1.28	1.20	1.02
		± 0.51	± 0.03	± 0.08	± 0.01	± 0.03	± 0.01
pH of the buffer
5.90	−1	14.693	3.133	7.795	1.28	1.25	1.01
6.00	0	14.648	3.137	7.850	1.27	1.22	1.02
6.10	+1	14.617	3.138	7.898	1.24	1.22	1.00
Mean ± S.D.		14.653	3.136	7.848	1.26	1.23	1.01
		± 0.04	± 0.01	± 0.05	± 0.02	± 0.02	± 0.01
Columns from different manufacturers
HiQ-Sil™ HS C18		14.648	3.137	7.850	1.27	1.22	1.02
BDS Hypersil C18		14.650	3.142	7.858	1.34	1.28	1.08
Mean ± S.D.		14.649	3.139	7.854	1.31	1.25	1.05
		± 0.001	± 0.003	± 0.006	± 0.04	± 0.04	± 0.04

^aAverage of three concentrations 40, 100, and 160 μg mL⁻¹ for ACF, 130, 325 and 520 μg mL⁻¹ for PCM and 15, 37.5 and 60 μg mL⁻¹ for TRM.