Archive for the ‘LC’ Category

How can I use Raptor columns and the EXP Direct connect holder with stainless steel fittings?

Some customers may find themselves with this scenario. You have an HPLC instrument with existing stainless steel tubing and fittings and you are getting ready to install a Raptor column. The end of your tubing may very well look like the one shown above. Here are some questions you might have.   Can I attach […]

LC Columns: High-Pressure Survival of the Fittest!

As an R&D Chemist charged with developing the perfect packing method for new LC columns, one of the challenges is finding a packing method that results in a column which not only passes QC specifications but also passes our arduous lifetime analysis. During lifetime testing our columns are subjected to 1,000 continuous injections at 12,000 […]

The Clog Blog

Clogging and over pressuring are definitely problematic for Liquid Chromatography columns. Back in 2005 John Dolan’s sage advice to chromatographers to make an LC column last forever was simple, “Never open the box!” As John pointed out, this is not practical and I have to agree. But as an LC column manufacturer I have seen […]

Top 16 for 2016 – Restek LC Article Makes the Cut

If you are an avid chromatographer you likely subscribe to LC/GC magazine or its popular electronic version, E-Separation Solutions. It is definitely the place to go for news and information related to all things Chromatography. Over the years Restek has had many an article published in LC/GC and, full disclosure, we advertise there as well. Who […]

Fluorophenyl LC Phases- what you should know

They may be called PFP, PFPP, pentafluorophenyl, fluorophenyl or F5 phases. What they all have in common is the structure shown above (the pentafluorophenyl  group) attached to the silica particles. Most modern phases contain a propyl spacer between the above group and the silica, so that the phase looks something like this:     A […]

Need parts for your Agilent 1100? HP 1050? Restek has you covered.

As of May 31, 2015, 1100 Series HPLC systems were categorized “End of Guaranteed Support” (EGS) by Agilent. Agilent would prefer it if you purchased a new system from them, but 1100 HPLCs are dependable workhorses. Why not keep them running with instrument replacement parts from Restek? Check out our selection, easily sorted by instrument and module: […]

Can HPLC-UV Be Used For Terpenes Analysis In Cannabis?

While HPLC may be tempting to use for terpenes analysis, a GC/FID or GC/MS is really the most straightforward and recommended way of analyzing terpenes in cannabis. Terpenes, being relatively volatile and neutral, lend themselves rather nicely to GC in general. As you can see from Figure 1 below, coelutions of the cannabinoids and terpenes are very likely when […]

Update on Guard Cartridges for Trident Holders

        You may have seen my last blog post about guard holders and cartridges that we have available for our various LC product lines, “Which guard cartridges and holders go with which LC analytical columns?” Along those lines of discussion, the following note is available to also show what specific products are […]

Why Biphenyl is a very interesting primary choice as stationary phase in LC..

Being a GC chemist for almost 38 years I always wondered why most LC separations are performed on a C18. A C18 is an extremely good non-polar stationary phase and is the foundation of reversed-phase chromatography, where polar mobiles phases are used with non-polar stationary phases. But there are so many C18 phases, how do […]

Which guard cartridges and holders go with which LC analytical columns?

As our family of LC products has grown, so have our choices for columns and accompanying guard cartridges. Here is a handy chart to show which guard holder and guard cartridges were intended for use with each type of analytical column. Please feel free to click the links to access each group of products on […]