Page 27 - BR20828_E Accucore 0713S

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Figure 2: Performance comparison using Poppe plot (plate generation time versus efficiency) for Accucore and competitor solid core
columns. All columns: 100 x 2.1 mm; test conditions: mobile phase 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 impedance. As demonstrated in
Figure 3, the Accucore column exhibits the lowest
impedance of all solid core columns tested. The average
impedance of the Accucore 2.6 μm column is 7% lower
than the material with the second lowest impedance
(Halo 2.7 μm) and 51% lower than the material with
the highest impedance across the range (Poroshell 120
2.7 μm).
t 0 /N (s)
N (/)
3.0E-04
3.0E-03
1.3.0E-02
5.0E+03 5.0E+04
Accucore RP-MS 2.6 µm
Nucleoshell RP-C18 2.7 µm
Poroshell 120 SB-C18 2.7 µm
Halo C18 2.7 µm
Kinetex C18 2.6 µm
Ascentic Express C18 2.7 µm
Sunshell C18 2.6 µm
Efficiency Comparison
In Figure 2, the Accucore column’s speed in generating
plates is compared to the competitor phases. This
kinetic plot is often referred to as a Poppe plot
[2]. In this type of plot the plate generation rate is
plotted against efficiency. Lower values on the y-axis
represent the ability to generate narrow peaks quickly.
The Accucore column is the best-performing column
when using this comparison, demonstrating that it
provides the most efficient peaks per unit time. At
the optimum point of the curve, the Accucore 2.6 μm
column shows the best combination of plate generation
rate / efficiency. On average, the plate generation
rate of the Accucore 2.6 μm, Halo 2.7 μm (Advanced
Materials Technology, Inc., Wilmington, DE, USA)
and Ascentis® Express 2.7 μm (Sigma-Aldrich Co.,
St. Louis, MO, USA) columns are similar and 28%
better than the column with the worst plate generation
rate (Sunshell 2.6 μm).
Column Backpressure Comparison
The solid core particles, tight control of particle
diameter, and automated packing processes used
in Accucore HPLC columns all contribute to low
backpressures. Figure 1 shows how the column
backpressure of an Accucore 2.6 μm column compares
with the other solid core columns tested (Table 1).
With the exception of the SunShell® 2.6 μm column
(ChromaNik Technologies, Inc., Osaka, Japan) the
Accucore column exhibits the lowest backpressure,
across the flow rate range, tested for all of the columns
tested. However, the SunShell material exhibits lower
efficiencies.
Even when run at a flow rate of 1 mL/min, the
backpressure of the 100 x 2.1 mm Accucore column
is below 500 bar. This is 22% lower than the
backpressure generated by the Poroshell 120 2.7 μm
column (Agilent Technologies Inc., Santa Clara, CA,
USA) under the same conditions, which is the column
with the highest backpressure across the flow rate
range.