Heavy metals: Accuracy

  The accuracy of the method was evaluate on the test matrix (samples collected in Ostia) by the Standard Addition Method (2 additions).

  Data obtained in the analyses of all the considered metal ions are reported in the first table together with the first index of accuracy (%recovery).

  The second table reports a different index obtained by the following calculation; the computed concentration value is obtained by solving (the C_s value) the following equation system:

  Where C_a=added concentration, C₁=concentration after the first addition, C₂=concentration after the second addition, C_s=computed concentration, V_a=added volume, V_s=sample volume, and in the bottom equation, C_x=measured concentration before addition. The accuracy % is computed by:

  Values obtained