Chapter 20, Problem 20.10P

(a)

Interpretation Introduction

Interpretation:

Concentration of added standard has to be calculated.

Concept Introduction:

Formula to calculate ${\left[\text{S}\right]}_{\text{final}}$ in diluted solution is as follows:

  ${\left[\text{S}\right]}_{\text{final}}={\left[\text{S}\right]}_{\text{intial}}\left(\frac{V_{\text{S}}}{V}\right)$

Here,

$V$ is total volume obtained from sum of $V_{\text{S}}$ and $V_{\text{0}}$.

${\left[\text{S}\right]}_{\text{intial}}$ denotes initial concentration of standard.

${\left[\text{S}\right]}_{\text{final}}$ denotes final concentration of standard after unknown addition.

(b)

Interpretation Introduction

Interpretation:

Original concentration of ${\text{K}}^{+}$ in serum has to be calculated.

Concept Introduction:

Standard addition equation is as follows:

  $\frac{{\left[\text{X}\right]}_{\text{i}}}{{\left[\text{X}\right]}_{\text{f}}+{\left[\text{S}\right]}_{\text{f}}}=\frac{I_{\text{X}}}{I_{\text{S}+\text{X}}}$

Here,

$I_{\text{X}}$ denotes signal in unknown for analyte.

$I_{\text{S}+\text{X}}$ denotes signal with mixture.

${\left[\text{X}\right]}_{\text{i}}$ denotes initial concentration of analyte in unknown.

${\left[\text{S}\right]}_{\text{f}}$ denotes final concentration of standard after unknown addition.