Minerals NIST Found Ca 5.05 ± 0.09 4.99 ± 0.07 K 2.70 ± 0.05 2.76 ± 0.07 Mg 1.20 1.08 ± 0.02 Na 136 ± 4 157 ± 2 P 0.216 ± 0.004 0.217 ± 0.006 Cu 4.7 ± 0.14 4.8 ± 0.12 Fe 368 ± 7 369 ± 4 Mn 246 ± 8 255 ± 9 Zn 30.9 ± 0.7 30.3 ± 0.8

Table 2: Results of Certified Reference Material (SRM) NIST 1573a