Ascentis^® Express U/HPLC Column Selection

Column selection by phase chemistry

The column selectivity has the highest influence on resolution in chromatography. Therefore, the selection of the best suitable column chemistry for the target analytes is an important selection parameter. C18 column chemistries are typically the first choice. Nevertheless, when a C18 doesn't give the desired separation or the sample contains compounds that are known to be difficult to retain or resolve on a C18, consider changing stationary phases. The range of selectivity provided by Ascentis^® Express makes this easy. The flowchart below helps guide users in the selection of an Ascentis^® Express phase, based on the particular compound type or separation challenge

column selection by column dimension

The separation goals, detection method and the instrument used for the separation define the column dimension and the particle size.

Select Column ID
Needs	Column ID (mm)	Typical Flow Rate (mL/min)
Best Suitability for Mass Spec and UHPLC	2.1	0.2 – 1.0
Solvent Savings in HPLC	3.0	0.5 – 2.0
Standard HPLC	4.6	1.0 – 3.0

Select Column Length
Needs	Column Length (mm)
Maximize Speed	20 - 75
Balance of Resolution and Speed	100
Maximize Resolution	150

Select Particle Size
Needs	Particle Size (µm)
UHPLC / High Throughput	2.0
Fast on any HPLC System	2.7
"Plug and Play" for Improving Existing HPLC Methods	5.0