Page 39 - BR20828_E Accucore 0713S

Technical Note 20667

Comparison of the Chromatographic

Resolution of Solid Core 4 μm and Fully

Porous 3 μm and 5 μm Columns

Luisa Pereira, Ken Meadows, Anila Khan, Thermo Fisher Scientific, Runcorn, Cheshire, UK

Introduction

The primary goal of developing a chromatographic

separation is to resolve a mixture of analytes. From the

general resolution equation (Equation 1), it is evident

there are three parameters that control resolution, namely

efficiency (N), selectivity (

α

), and retention (k') factors.

Selectivity and retention factor are analyte-dependent and

can be improved by changing the column chemistry,

mobile phase composition, or temperature. The third

parameter, efficiency, is analyte-independent. Therefore,

columns that provide improved efficiency have a wider

chromatographic applicability.

Equation 1.

Chromatographic efficiency, and therefore resolution, can

be increased by use of a longer column, however this

results in a longer analysis time. The favored methods of

increasing chromatographic efficiency are a reduction in

the particle size or a change to solid core particles, which

for the same particle size produce sharper, more efficient

peaks and hence better separations than fully porous

materials. An advantage of converting from fully porous

to solid core materials of a similar particle size for

improved efficiency is that users of conventional HPLC

methods in regulated environments can change the

column format without the need of a full revalidation

under the current regulatory guidelines.

Using a solid core 4 µm particle packed in conventional

column dimensions, significant improvements in the

assay performance can be achieved without the need to

make changes to the operating parameters or system

Key Words

Solid core, fused core, superficially porous, resolution, efficiency,

productivity, Core Enhanced Technology

Abstract

In this technical note, the chromatographic resolution of solid core 4 µm

particle packed columns is compared with that of fully porous 5 and 3 µm

particle packed columns.

configuration. Based on Core Enhanced Technology™

using 4 µm solid core particles, Thermo Scientific™

Accucore™ XL HPLC columns allow users of

conventional HPLC methods to obtain performance far

beyond that of columns packed with 5 µm or even 3 µm

fully porous particles. Very high peak efficiencies using

standard HPLC instrumentation and conditions allow for

increased peak resolution for the same stationary phase

chemistry. Additionally, the lower volume of mobile phase

in columns packed with solid core particles (i.e., lower v

0

or t

0

) combined with a higher optimal linear velocity

results in improved productivity.

R = s

k'

N

1

4

( (

(

k'

1 +

1

α