Page 29 - Shimadu Consumables Catalog

Rapid Equilibration (Even with Low Ionic Strength Acidic Mobile Phases)

When analyzing basic compounds on a typical ODS column with low
HN
ionic strength acidic mobile phase, peak shape and long equilibration
times are common problems. Shim-pack Arata LC columns can be H
rapidly equilibrated in low ionic strength acidic mobile phases N
yielding excellent peak shape and stable retention times.
1. Dextromethorphan 2. Amitriptyline

Analytical Conditions
Instruments : NexeraX2MP_M30A (STD Cell)
Column : Shim-pack Arata C18
(3.0 × 75 mm, 2.2 μm)
Typical ODS column
(3.0 × 75 mm, sub 2 μm),
Mobile Phase : 0.1% HCOOH in H2O / CH3CN = 70 / 30
Flow Rate : 0.4 mL/min
Detection : 280 nm
Column Temp. : 40 °C
Inj. Volume : 2 μL
Sample : Amitriptyline, Dextromethorphan

Equilibration Time
Compounds 10 30 60 120 180 240 360 480 600 720 CV(%)
(min)
Retention Time (min) 0.8 0.8 0.8 0.8 0.8 0.8 0.8 0.8 0.8 0.8 0.2
1 Dextromethorphan
Symmetry Factor 1.20 1.19 1.19 1.18 1.18 1.18 1.18 1.18 1.18 1.18 0.6
Retention Time (min) 1.4 1.4 1.4 1.4 1.4 1.4 1.4 1.4 1.4 1.4 0.3
2 Amitriptyline
Symmetry Factor 1.06 1.07 1.06 1.06 1.06 1.06 1.06 1.06 1.06 1.06 0.3

* Both were new columns (shipping solvent : acetonitrile) and equilibrated
with mobile phase without any conditioning. Basic drugs were analyzed
after a certain period of time of equilibration and RT and symmetry
factor of the drugs were compared.

Equilibration Time
Compounds 10 30 60 120 180 240 360 480 600 720 CV(%)
(min)
Retention Time (min) 1.9 1.8 1.7 1.6 1.5 1.5 1.5 1.4 1.4 1.4 10.4
1 Dextromethorphan
Symmetry Factor 3.28 3.14 3.01 2.70 2.63 2.56 2.51 2.49 2.56 2.49 10.2
Retention Time (min) 5.3 4.7 4.3 4.0 3.9 3.8 3.7 3.6 3.5 3.6 13.5
2 Amitriptyline
Symmetry Factor 4.23 4.23 4.35 4.22 4.13 4.17 4.09 4.02 3.99 3.90 3.1
Comparison of Column Equilibration in The Mobile Phase with 0.1% Formic Acid (Shim-pack Arata C18 vs. Typical ODS Column)

Shim-pack Arata C18

I.D. (mm)
Particle Size (μm) 2.0 3.0 4.6
Length (mm)
50 227-32801-01 227-32802-01 -
75 227-32801-02 227-32802-02 -
2.2 100 227-32801-03 227-32802-03 -
150 227-32801-04 227-32802-04 227-32805-04
250 - - 227-32805-05
50 227-32803-01 227-32804-01 227-32805-01
75 227-32803-02 227-32804-02 227-32805-02
5.0 100 227-32803-03 227-32804-03 227-32805-03
150 227-32803-04 227-32804-04 227-32805-04
250 - - 227-32805-05

Pg A-25