Author Archive

What can I use to Qualify my HPLC instrumentation?

If you are setting up LC instrumentation in a new lab, you may find yourself looking for ways to perform Operational Qualification (OQ) tests. The requirements for qualifying a new instrument vary, depending on regulatory needs and SOP requirements, as well as the specific instrumentation. They might involve tests to confirm parameters such as solvent […]

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 […]

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 […]

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 […]

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 […]

What can I use to filter my mobile phase?

If you are using mobile phase that contains salts or, generally, any components that are weighed out for its preparation, you will need to filter the solution before using with HPLC or UHPLC. The most common type of filtration is membrane microfiltration. We sell an extensive group of products for this and they are discussed […]

What can I use as a cap for my mobile phase bottles?

Our choices for mobile phase bottle tops are based primarily on two different products. The first product is the Hub-Cap Bottle Top, catalog #26541. This is designed to fit a 4-Liter solvent bottle. :     The body (also called insert) of the Hub-Cap Top is cap is made of inert PTFE and has three […]

What is the pressure limit for my LC column?

This is a question we get in Tech Services fairly often.  Unfortunately, we are not able to provide a published limit for every column that we produce, but here are a few of them that we have specified: For 3 and 5 um fully porous particle ROC LC columns, the maximum operating pressure is 400 […]

Is it OK to use THF (tetrahydrofuran) on my HPLC?

Well, it might be. In the early days of HPLC, THF was commonly used as a mobile phase solvent. It has eluting strength similar to acetonitrile, but just slightly stronger. Since it technically is an ether and is very miscible with water, it is sometimes useful with reverse phase HPLC. It also provides additional options […]

Calculating pH

I’m guessing that most of us that work in the lab would find it more convenient to measure a pH rather than to calculate a theoretical value.  But, at times, it can be very useful to make that calculation and get an idea of what to expect.  As far as chromatography is concerned, all columns […]