Table 2 Results of the measurement of accuracy for the certified, reference, and in-house standardized samples using the standard addition method

Cu

2.1 ± 0.2^a

2.2

4.8

Fe

14.1 ± 0.5^a

14.4

2.1

Mg

400 ± 20^a

409

2.3

Mn

9.4 ± 0.9^a

10.0

6.4

Mo

0.48 ± 0.03^a

0.45

6.3

Ni

7.89 ± 0.57^b

7.73

2.0

Cr

48.6^c

47.0

3.2

Pb

1.9^c

2.0

4.2

V

1.6^c

1.5

6.3

U

0.193^c

0.203

5.2

Bi

0.037^c

0.035

5.4