We are not aware of any systematic studies with respect to the impact of flow rate on HILIC separations. Our concern would be that as you move to higher flow rates, you might observe peak shape issues due to the slow kinetics of IEX and adsorption mechanisms. If the retention mechanisms for a given system are partition dominated, this should be of less concern. It will be a case by case cause and effect.
53933-U
Ascentis® Express 90 Å HILIC (2.7 μm) HPLC Columns
L × I.D. 3 cm × 2.1 mm, HPLC Column
About This Item
Recommended Products
Product Name
Ascentis® Express HILIC, 2.7 μm HPLC Column, 2.7 μm particle size, L × I.D. 3 cm × 2.1 mm
material
stainless steel column
Quality Level
Agency
suitable for USP L3
product line
Ascentis®
feature
endcapped: no
manufacturer/tradename
Ascentis®
packaging
1 ea of
parameter
≤100 °C temp. range
600 bar max. pressure (9000 psi)
technique(s)
HPLC: suitable
LC/MS: suitable
UHPLC-MS: suitable
UHPLC: suitable
L × I.D.
3 cm × 2.1 mm
surface area
135 m2/g
impurities
<5 ppm metals
matrix
Fused-Core particle platform
superficially porous particle
matrix active group
silica phase
particle size
2.7 μm
pore size
90 Å
operating pH
1-8
application(s)
food and beverages
separation technique
hydrophilic interaction (HILIC)
normal phase
Looking for similar products? Visit Product Comparison Guide
Related Categories
General description
Visit the Ascentis Express home page for more information on this new column technology.
Legal Information
guard cartridge
related product
required but not provided
Storage Class Code
11 - Combustible Solids
WGK
WGK 3
Flash Point(F)
Not applicable
Flash Point(C)
Not applicable
Choose from one of the most recent versions:
Certificates of Analysis (COA)
Don't see the Right Version?
If you require a particular version, you can look up a specific certificate by the Lot or Batch number.
Already Own This Product?
Find documentation for the products that you have recently purchased in the Document Library.
Articles
For separation of polar compounds including polar neutrals, polar acids, and polar and non-polar basic amines use our Ascentis® Express HILIC column.
For separation of polar compounds including polar neutrals, polar acids, and polar and non-polar basic amines use our Ascentis® Express HILIC column.
For separation of polar compounds including polar neutrals, polar acids, and polar and non-polar basic amines use our Ascentis® Express HILIC column.
For separation of polar compounds including polar neutrals, polar acids, and polar and non-polar basic amines use our Ascentis® Express HILIC column.
Protocols
We offer the tools for the analysis of the metabolites; including certified reference standards, enzymes, substrates, and chromatographic products.
-
How does the flow rate influence the water layer on the column?
1 answer-
Helpful?
-
-
Why is it recommended to run isocratically for HILIC methods?
1 answer-
When running in HILIC mode, both isocratic and gradient practices result in instability. If you keep the re-equilibration times constant, gradient should not be a problem, but changing this parameter can have a significant impact. It is not so much that it is bad as it is different than we are used to in reversed phase. Usually, we assume that once equilibrated (5, 10, 15 min, etc.), we can leave the system for any time period and come back to the same results. This does not appear to be the case in our studies of HILIC. Knowing that the re-equilibration time has an impact, you should get in the habit of making several injections with known re-equilibration times prior to making any development decisions. To get around this, isocratic runs are recommended. Attached are two posters; the first was presented at HPLC 2013 (Amsterdam) and the second was presented at Balaton Symposium on High Performance Separation Methods 2013 (Hungary). Both show 'reproducibility' at any set re-equilibration time is good but both show that if you change the re-equilibration time; then retention, peak shape and selectivity can change especially where ionic interactions are prevalent.
Helpful?
-
-
What column do you recommend for an anionic compound?
1 answer-
If the acids are hydrophilic or you can adjust the pH to make them hydrophilic enough, any of the phases that exhibit HILIC partitioning are possible (bare silica, OH5, diol, Zwitterionic, amide). We typically go with the OH5 first to try and avoid any negative impacts on the like charge.
Helpful?
-
-
When referring to the pH of the mobile phase (pH 3, pH 4, etc.), does that refer to the aqueous part of the mobile phase?
1 answer-
Typically when we refer to pH in HILIC, we use the effective pH or the pH as measured after the addition of organic. The point is that we should always define what pH we are stating. The common way to distinguish is using notation of w/w pH or s/w pH (usually superscript/subscript). The notations mean superscript = solvent the pH is measured in (s would indicate some mixture of aqueous:organic) and the subscript = the solvent the pH meter is calibrated in (typically water (or w) as we readily have calibration standards).
Helpful?
-
-
Do I need special fittings and tubing to connect Ascentis® Express HPLC Columns?
1 answer-
While operating pressures may not exceed the 400 bar (6,000 psi) capability of your traditional instruments, sustained pressures of about 200 bar (3,000 psi) will exceed the recommended pressure for conventional PEEK tubing and fittings at the column inlet. We recommend changing to stainless steel fittings in all high pressure locations and have designed special High Performance HPLC Fittings/Interconnects that will stay tight at pressures of 1,000 bar (15,000 psi) or greater, even when elevated column temperatures are employed.
Helpful?
-
-
Can I use Ascentis Express on a UHPLC system?
1 answer-
Yes. Ascentis Express columns are packed in a way making them suitable for these ultra high pressure instruments. In fact, Ascentis Express outperforms sub-2 μm micron columns on many applications since Ascentis Express provides the benefits of sub-2 μm particles but at much lower back pressure. These benefits include the capability of providing fast HPLC and higher resolution chromatography. The Fused-Core particle consists of a 1.7 μm solid core and a 0.5 μm porous shell. A major benefit of the Fused-Core particle is the small diffusion path (0.5 μm) compared to conventional fully porous particles. The shorter diffusion path reduces axial dispersion of solutes and minimizes peak broadening.
Helpful?
-
-
What flow rate should I use with Ascentis® Express HPLC Columns?
1 answer-
Based on the minimum in the van Deemter curves, higher flows than 5um particle columns are required in order to maximize Ascentis Express column efficiency. The suggested starting point for flow rate for Ascentis Express columns: 1.6 mL/min for 4.6 mm ID; 0.8 mL/min for 3.0 mm ID; and 0.4mL/min for 2.1 mm ID.
Helpful?
-
-
Would you advise addition of a buffer when using diol or amide stationary phase?
1 answer-
Yes. if possible you should always have at least a small amount of buffer in a HILIC system to help mediate/control IEX and other polar interactions that are bound to be present (even if at a low level). It is not so much the "buffering capacity" that is important, but the presence of the competing ions. We have found that their presence helps with day to day and column to column reproducibility. There are times when you need to eliminate the buffer, but aside from special circumstances, our recommendation is to include them.
Helpful?
-
-
Can I use Ascentis Express on any type of HPLC system?
1 answer-
Ascentis Express HPLC columns are capable of use on standard HPLC systems as well as UHPLC systems. Columns are packed in high pressure hardware capable of withstanding the pressures used in UHPLC systems.
Helpful?
-
-
How should I store the Ascentis Express HILIC column?
1 answer-
Long-term storage of silica-based columns is best in 100% acetonitrile. Columns may be safely stored for short periods (up to 3 or 4 days) in most common mobile phases. However, when using buffers, it is best to remove the salts to protect both the column and the HPLC equipment by first flushing the column with the same mobile phase without the buffer (e.g., when using 90/10 ACN/buffer, flush the column with 90/10 ACN/H2O) to eliminate any concern about salt precipitation or corrosion from the salts then flush the column with 100% acetonitrile for storage.Before storing the column, the end-fittings should be tightly sealed with the endplugs that came with the column to prevent the packing from drying.
Helpful?
-
Active Filters
Our team of scientists has experience in all areas of research including Life Science, Material Science, Chemical Synthesis, Chromatography, Analytical and many others.
Contact Technical Service