Table 1 Certified NIST elemental analysis of standard reference material [61, 62]

Aluminum

7.50 ± 0.06

6.44 ± 0.08

Calcium

1.89 ± 0.05

1.25 ± 0.03

Iron

3.50 ± 0.11

3.38 ± 0.10

Magnesium

1.51 ± 0.05

0.853 ± 0.042

Phosphorus

0.062 ± 0.005

0.106 ± 0.015

Potassium

2.03 ± 0.06

2.11 ± 0.11

Silicon

29.66 ± 0.23

28.97 ± 0.18

Sodium

1.16 ± 0.03

1.14 ± 0.06

Sulfur

0.089 ± 0.002

0.240 ± 0.006

Titanium

0.342 ± 0.024

0.283 ± 0.010

Arsenic

17.7 ± 0.8

626 ± 38

Cadmium

0.38 ± 0.01

21.8 ± 0.2

Copper

34.6 ± 0.7

2950 ± 130

Lead

18.9 ± 0.5

5532 ± 80

Manganese

538 ± 17

22,124 ± 876

Mercury

1.40 ± 0.08

32.6 ± 1.8

Zinc

106 ± 3

6952 ± 91