Chapter 27, Problem 27.23QAP

Interpretation Introduction

(a)

Interpretation:

Retention factors for each component should be calculated.

Concept introduction:

The retention factor can be calculated as follows:

$\begin{array}{l}k=\frac{t_R-t_M}{t_M}\\ \text{where:}\\ \text{k=}\text{Retention}\text{factor}\\ {\text{t}}_{\text{R}}\text{=Retention}\text{time}\text{of}\text{interested}\text{species}\\ {\text{t}}_{\text{M}}\text{=}\text{Migration}\text{time}\text{of}\text{unretained}\text{species}\end{array}$

Interpretation Introduction

(b)

Interpretation:

Selectivity factor for methyl acetate and methyl propionate and methyl propionate and n-butyrate should be calculated.

Concept introduction:

Selectivity factor can be calculated as follows:

Methyl acetate and methyl propionate.

Methyl propionate and n-butyrate.

$\begin{array}{l}\alpha =\frac{{\left(t_R\right)}_B-t_M}{{\left(t_R\right)}_A-t_M}\\ where:\\ a=Selectivityfactor\\ {\left(t_R\right)}_{A}and{\left(t_R\right)}_B=RetentiontimeofsubstanceAandBrespectively\\ t_M=Migrationtimeofunretainedspecies\end{array}$

Interpretation Introduction

(c)

Interpretation:

Average plate number and plate height should be calculated.

Concept introduction:

Number of theoretical plates can be calculated as follows:

$\begin{array}{l}N=16{\left(\frac{t_R}{W}\right)}^2\\ \text{where:}\\ \text{N=Number}\text{of}\text{plates}\\ {\text{t}}_{\text{R}}\text{=Retention}\text{time}\\ \text{W=Width}\text{of}\text{peak}\text{base}\end{array}$

Plate height can be calculated using following equation.

$\begin{array}{l}H=\frac{L}{N}\\ \text{where:}\\ \text{H=Plate}\text{height}\\ \text{L=Length}\text{of}\text{column}\text{packing}\\ \text{N=Number}\text{of}\text{plates}\end{array}$

Interpretation Introduction

(d)

Interpretation:

Resolution formethyl acetate and methyl propionate and methyl propionate and n-butyrate should be calculated.

Concept introduction:

Resolution can be calculated as follow:

$\begin{array}{l}R=\frac{2\left[{\left(t_R\right)}_B-{\left(t_R\right)}_A\right]}{W_A+W_B}\\ \text{where:}\\ \text{R=Resolution}\\ {\left({\text{t}}_{\text{R}}\right)}_{\text{A}}\text{and}{\left({\text{t}}_{\text{R}}\right)}_{\text{B}}\text{=Retention}\text{times}\text{of}\text{A}\text{and}\text{B}\text{respectively}\\ {\text{W}}_{\text{A}}\text{and}{\text{W}}_{\text{B}}\text{=Peak}\text{widths}\text{for}\text{A}\text{and}\text{B}\end{array}$