. Author manuscript; available in PMC: 2022 Apr 1.

Published in final edited form as: J Chromatogr B Analyt Technol Biomed Life Sci. 2021 Feb 21;1168:122591. doi: 10.1016/j.jchromb.2021.122591

Table 4.

Back calculated concentrations from calibrators run in duplicate on four consecutive days

Nominal Conc. (ng/mL)	N	Mean (ng/mL)	RSD (%)	DEV (%)
2.5	8	2.42	5.16	−3.07
5	8	5.41	3.27	8.21
12.5	8	11.9	2.51	−5.14
25	8	25.0	5.92	−0.22
50	8	56.2	3.18	12.4
125	8	124	3.35	−0.69
250	8	225	2.67	−10.1

Abbreviations: RSD, relative standard deviation; DEV, deviation from the nominal value; N, total number of observations during validation.