Metals Observed concentration Certified value
  Sediment without Cu- MBDTC Sediment with Cu- MBDTC  
Nickel (Ni) 17.2 ± 0.41 19.8 ± 0.7 23
Chromium (Cr) 24.7 ± 0.1 27.9 ± 0.5 30
Cobalt (Co) 9.07 ± 0.34 14.5 ± 0.21 11
Manganese (Mn) 917 ± 4 981 ± 11 1200
Lead (Pb) 11.3 ± 0.5 12.2 ± 1.3 13
Table 3: Observed concentrations (μg/g) of metals in standard reference material (ST-SD-4) and certified values (n = 5)