An On-Line Solid Phase Extraction-Liquid Chromatography-Tandem Mass Spectrometry Method for the Determination of Perfluoroalkyl Acids in Drinking and Surface Waters

Table 3

Validation parameters (injection in “early gradient” mode of 5 mL of acidified standards and samples).

	Linearity^a		Precision (RSD%)^b		Trueness (%)^c		Sensitivity (ng/L)
	(ng/L)		Intraday	Interday	TW	RW	LOD	LOQ
PFBA	2–200	0.955	7–27	10–33	76	83	5.0	20
PFPeA	2–200	0.962	10–32	10–28	115	88	2.0	4
PFHxA	2–200	0.969	2–8	8–33	98	103	0.2	1
PFHpA	2–200	0.970	2–9	6–14	116	111	0.2	5
PFOA	2–200	0.963	1–13	8–12	91	103	0.5	3
PFNA	2–200	0.960	4–12	10–16	92	119	0.5	1
PFDA	2–200	0.985	10–20	16–39	110	119	0.5	1
PFUnDA	1–100	0.972	10–31	24–53	119	109	0.5	1
PFDoDA	1–100	0.971	10–35	30–65	134	112	1.0	2
PFBS	2–200	0.990	6–28	11–44	115	80	1.0	10
PFHxS	2–200	0.970	4–13	10–25	103	103	5.0	20
PFOS	2–200	0.989	8–49	14–48	87	105	2.5	10

Values not corrected by SIL-IS; ^alinearity was calculated with the analysis of five levels of aqueous standard solutions; ^bprecision is calculated by injecting standards in the 1–100 ng/L range for PFUnDA and PFDoDA and 2–200 ng/L range for the other target compounds (intraday: = 3; interday: = 12); ^ctrueness is expressed as recoveries determined by analysing native-spiked tap waters (TW) and river waters (RW) at 100 ng/L level.