Page 31 - BR20828_E Accucore 0713S

3 Efficiency comparison
Figure 2 compares the efficiency of the Accucore XL
4 μm column with that of the Accucore 2.6 μm column
using a van Deemter plot. On average (across the flow
rate range tested) Accucore 2.6 µm gives 27% higher
efficiency than the Accucore XL 4 μm column, and the
improvement in efficiency increases as the linear velocity
increases.
The curves for both columns are very flat, and therefore
a wide range of linear velocities (or mobile phase flow
rates) can be used without losing chromatographic
performance. The flattest regions of the van Deemter
curve correspond to a mobile phase flow rate range of
0.9 to 1.4 mL/min for the Accucore XL 4 μm column and
1.2 to 1.8 mL/min for the Accucore 2.6 μm column.
Figure 2: Efficiency comparison using van Deemter plots for Accucore XL 4 µm and Accucore 2.6 µm columns
All columns 150 × 4.6 mm; test conditions: water / acetonitrile (50:50 v/v) mobile phase, 30 °C column
temperature, test probes: phenetole and theophylline (t0 marker)
Plate height (H,μm)
Linear velocity u (mm/s)
1.0
0.0
2.0
3.0
4.0
5.0
6.0
7.0
8.0
9.0
10.0
0.5 0.0 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5
Accucore XL 4 μm Accucore XL 2.6 μm
Impedance comparison
Impedance is a term that gives a true measure of the
performance of the column as it incorporates efficiency,
time, and pressure, which are critical parameters for
chromatographers. Lower impedance values indicate
faster chromatography and generation of narrower peaks
at lower backpressures. The solid core particles, tight
control of particle diameter, and automated packing
processes used in Accucore HPLC columns contribute to
low impedances.
On average (across the flow rate range tested) the
Accucore 2.6 μm column provides 20% more efficiency
per unit time than the Accucore XL 4 μm column
(Figure 3). In terms of overall performance of both
4 and 2.6 μm materials, the Accucore 2.6 μm column
demonstrates 37% lower impedance (Figure 4).
Figure 3: Performance comparison of Accucore XL 4 µm and Accucore 2.6 µm columns using kinetic plots:
efficiency per unit time
All columns 150 × 4.6 mm; test conditions: water / acetonitrile (50:50 v/v) mobile phase, 30 °C column
temperature, test probes: phenetole and theophylline (t0 marker)
t 0 (s)
N (/)
1.E+02
1.E+01
1.E+03
1.E+05 1.E+04
Accucore XL 4 μm Accucore 2.6 μm