Page 37 - BR20828_E Accucore 0713S

3 Efficiency Comparison
Figure 2 compares the efficiency of the Accucore XL
4 μm material with that of the fully porous 5 and 3 μm
materials tested using a van Deemter plot. On average
(across the flow rate range tested), the Accucore XL
4 µm material gives 75% more efficiency than fully
porous 5 µm and 50% more efficiency than fully porous
3 µm. The curve for the Accucore XL 4 μm HPLC
column is very flat; therefore, a wide range of linear
velocities (or flow rates) can be used without losing
chromatographic performance.
Figure 2: Efficiency comparison using van Deemter plots for Accucore XL 4 µm HPLC column and fully porous 5 µm and 3 µm columns.
All columns: 150 x 4.6 mm; test conditions: water / acetonitrile (50:50 v/v); column temperature: 30 °C; test probes: o-xylene and
theophylline (t 0 marker).
Figure 3: Performance comparison of Accucore XL 4 µm HPLC column and fully porous 5 µm and 3 µm columns using kinetic plots:
efficiency per unit time. All columns: 150 x 4.6 mm; test conditions: water / acetonitrile (50:50 v/v); column temperature: 30 °C; test
probes: o-xylene and theophylline (t 0 marker).
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 all
contribute to low impedances. On average (across the
flow rate range tested), the Accucore XL 4 µm HPLC
column provides the following:
• 59% more efficiency per unit time than fully porous
5 µm and 53% more efficiency per unit time than
fully porous 3 µm (Figure 3).
• 79% lower impedance than fully porous 5 µm and
72% lower impedance than fully porous 3 µm
(Figure 4).
Plate height (H,
µ m)
Linear velocity u (mm/s)
0.5 0.0
2.0
0.0
4.0
6.0
8.0
10.0
12.0
14.0
16.0
18.0
1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5
Accucore XL 4 µm
Fully porous 5 µm
Fully porous 3 µm
t 0 (s)
Efficiency (/)
1.E+01
1.E+00
1.E+02
1.E+03
1.E+04
1.E+04 1.E+05
Accucore XL 4 µm
Fully porous 5 µm
Fully porous 3 µm