Science

ChemistryPrinciples of Instrumental Analysis(a) Interpretation: The optimal velocity is to be stated. Concept introduction: The Van Deemeter equation relates the HPLC plate height and velocity of plate. The Van Deemeter equation is as follows. H = B u + C u = B u + C S u + C M u ...... (I) Here, the HPLC height is H , the plate velocity is u , the diffusion coefficient is B , the mass transfer coefficient in stationary phase is C S , the mass transfer coefficient in mobile phase is C M , the total mass transfer coefficient is C .Start your trial now! First week only $4.99!*arrow_forward*

BuyFind*launch*

7th Edition

Douglas A. Skoog + 2 others

Publisher: Cengage Learning

ISBN: 9781305577213

Chapter 28, Problem 28.23QAP

Interpretation Introduction

**(a)**

**Interpretation:**

The optimal velocity is to be stated.

**Concept introduction:**

The Van Deemeter equation relates the HPLC plate height and velocity of plate. The Van Deemeter equation is as follows.

Here, the HPLC height is

Interpretation Introduction

**(b)**

**Interpretation:**

The minimum plate height is to be stated.

**Concept introduction:**

The Van Deemeter equation relates the HPLC plate height and velocity of plate. The Van Deemeter equation is as follows.

The relation between HPLC height is inversely proportional to plate velocity. So minimum height is obtained corresponding to optimal velocity in the Van Deemeter equation.

Interpretation Introduction

**(c)**

**Interpretation:**

The optimal velocity and minimum height of plate in terms of the diffusion coefficient in mobile phase, particle size and dimensional analysis is to be stated.

**Concept introduction:**

The mass transfer coefficient relates the particle size and diffusion coefficient in mobile phase. The diffusion coefficient relates the dimensional constant and diffusion coefficient in mobile phase.

Interpretation Introduction

**(d)**

**Interpretation:**

The optimal velocity and minimum height of plate at unity order for dimensional constants.

**Concept introduction:**

The mass transfer coefficient relates the particle size and diffusion coefficient in mobile phase. The diffusion coefficient relates the dimensional constant and diffusion coefficient in mobile phase.

Interpretation Introduction

**(e)**

**Interpretation:**

The preceding conditions for reduced plate height to one third, the optimal velocity in these conditions and effect on number of theoretical plates is to be stated.

**Concept introduction:**

The plate height and number of theoretical plates directly depends on the particle size and optimal velocity inversely depends on particle size.

Interpretation Introduction

**(f)**

**Interpretation:**

The condition to reduce the plate height to one third without reducing the number of theoretical plates is to be stated.

**Concept introduction:**

The number of theoretical plates directly depends on the height of the plate and inversely to the column length.

Interpretation Introduction

**(g)**

**Interpretation:**

The two sources of band broadening which also contribute to overall width of HPLC peaks is to be stated.

**Concept introduction:**

The band broadening is defined as the reduction in separation of solute molecules in the column. This also reduces the quality and accuracy of the separation. The band broadening occurs due to longitudinal movement of particles in the column.