Conc. (ng/spot)

Intraday precision (n = 6)

Intermediate precision (n = 6)

Mean. ± SD

%RSD

Mean. ± SD

%RSD

60

367.72 ± 2.87

0.78

375.89 ± 4.77

1.27

80

480.19 ± 2.21

0.46

485.63 ± 4.91

1.01

100

593.90 ± 5.81

0.97

590.41 ± 1.464

0.25