Page 35 - BR20828_E Accucore 0713S

Technical Note 20641
Solid Core 4 μm HPLC Column
Comparison to Fully Porous 3 μm and
5 μm Columns: Efficiency and Pressure
Luisa Pereira, Thermo Fisher Scientific, Runcorn, Cheshire, UK
Introduction
The use of partially porous particles, with a diameter
between 2 and 3 µm, is gaining momentum, as these
provide similar efficiency to sub-2 µm particles but with
significantly lower column backpressures.
Often, however, solid core particles are packed into short,
narrow-bore columns, which has implications in terms of
the system set up. System dead volume and operating
parameters have to be optimized to get the best possible
performance out of the column.
It is demonstrated herein that by 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 set up. With
Thermo ScientificTM Accucore TM XL 4 µm HPLC columns,
it is possible to dramatically improve separation efficiency,
and therefore resolution and sensitivity over those
obtained with conventional fully porous 5 µm and 3 µm
particle packed columns. These improvements are
obtained with only a 40% increase in backpressure over
the 5 µm and a reduction in backpressure compared to
the 3 µm material. The Accucore XL 4 µm solid core
HPLC columns exhibit significantly lower impedance than
fully porous materials.
Equation 1, known as the Burke-Plummer equation,
shows the dependency of the pressure drop across the
column on a variety of experimental parameters. The
pressure is directly proportional to the column length,
flow rate, and mobile phase viscosity and is inversely
proportional to the square of the particle size diameter
and the square of the column internal diameter ID. The
interstitial porosity (the spaces between the particles
Key Words
Solid core, fused core, superficially porous, pressure, efficiency, impedance
Abstract
In this technical note, the chromatographic performance of solid core
4 µm particle packed HPLC columns is compared with that of fully porous
5 µm and 3 µm particle packed columns. Parameters compared are column
pressure, efficiency, and impedance.
that are accessible by the mobile phase) has a more
complicated relationship to the pressure. There are other
operating parameters that have an impact on the overall
system pressure, such as the ID and length of the
connecting tubing in the LC system, detector setup
parameters such as flow cell volume in UV or the ID and
length of the capillary components in ESI or APCI sources
in LC/MS.