We tested our inert CVD coating, Dursan®, in tough HPLC tests. Here's what we found out.
Aren't stainless steel and PEEK just fine for HPLC analysis? Well if you like to replace flow path components and columns due to corrosion, adsorption, carryover/cross contamination, or tube swelling then you'll be just fine with the status quo. If you're interested in reducing system maintenance and test failures, then read on.
In this blog post you will learn:
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Why an inert flow path is critical to HPLC applications.
Using non reactive materials (stainless steel is not one of them...) in HPLC sample transfer systems can be summed up in one word, consistency. There are lots of other, more specific, benefits of a non reactive surface (see the list below) but consistency ties into all of the threads nicely; be it financial consistency, test consistency, or consistency of quality. Consistency if why an inert HPLC flow path is critical.
The enemy of consistency, stainless steel and PEEK
Stainless steel: Chemical reactivity, corrosion, and abrasion can all lead to the introduction of molecules and ions that are not in your sample.
Stainless steel issues include:Get the scoop on how to improve corrosion resistance and prevent PEEK swelling problems. Sign up for our special webinar on improving HPLC.
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Dursan® Material Properties
Stainless and PEEK are not perfect but they're a good material choice for many HPLC applications. Dursan® can help improve test consistency under challenging test conditions or when flow paths are exposed to organic solvents that can cause swelling. So what is Dursan?
Dursan is a silicon, oxygen, carbon coating that is bonded to stainless steel flow paths by chemical vapor deposition. Wherever a vapor molecule can get to, we can coat it. That includes sintered metal frits and inner bores of needles. That means that you can get all the structural benefits of stainless steel (ie. heat resistance, high pressure capable, easy to work with, and low cost) and combine that with the non reactivity of a plastic free coating. Material benefits include:
So how can Dursan® make a difference in HPLC flow paths and columns?
Comparative tests of our corrosion resistant HPLC coating, Dursan, VS. uncoated stainless steel show orders of magnitude improvement in corrosion rate. ASTM G31 hydrochloric acid immersion of test coupons show the stainless steel surface corrodes at a 170x faster rate than the Dursan coated surface. That means less chance of contamination and improved flow path life.
HPLC Inert Surface
The comparative chromatograph below tells the story. The resolution quality of tetracycline on a stainless steel column was compared to a Dursan coated column. The Dursan coated column significantly improved the peak shape.
Prevent false positive tests and carryover contamination
Comparative non specific protein binding studies by Abbott Laboratories demonstrate the reduced risk of protein sticking and carryover.
A Quartz Crystal Microbalance with Dissipation monitoring (QCM-D) comparative study (below) showed significant protein adhesion to stainless steel surfaces. After a rinse with a non ionic surfactant, the Dursan surface showed almost no protein retention.
Get the most out of our inert coatings and see how SilcoTek can improve HPLC performance.