Archive for the ‘Troubleshooting’ Category

Getting Your LC Up and Running Again

Welcome Back!  You and your lab have been through a lot these last few months and now it’s time to get your LC back up and running.  After it has been down for a few months, it likely needs a little TLC before it’s performing optimally again.  Just like a car that sits around for […]

Did you know you can manage jagged bleed with a controlled cooling program?

GC column bleed sounds like one of those old problems people used to have. The XLB was developed to lower detection limits by minimizing bleed. Now, virtually all polysiloxane GC columns are low bleed, with thick film and high polarity phases being the exception. Modern GC-MS instruments are so sensitive that I’m rarely concerned about […]

How I clean a GC injection port

Recently I have been asked by several customers how to clean an injection port.  My initial answer is always the same, you should clean the injection port according to the manufacturer’s recommendations.  But what instructions do I provide when the injection port was manufactured by Restek?  I usually provide the same response but then I […]

Are PFAS sticking in your system?

Per- and polyfluoroalkyl substances (PFAS) are ubiquitous in our society and can be found in a wide range of consumer products; hence they are widely present in the environment, people and animals. They are persistent chemicals that have the potential to accumulate. Therefore, they are evaluated and monitored using a variety of methods and controlled […]

Purge and Trap weldment installation

Sometimes we get asked by customers for clarification when installing/connecting a new or replacement weldment from their purge & trap autosampler to their Agilent GC’s split/splitless injection port. As a result, I wrote this post to assist those that may be new to this type of installation or those that simply could use a quick […]

Not checking for leaks in your GC system has consequences

I know I am beginning to sound like a stuck record on this topic, but checking for leaks in your GC system on a daily basis, using an electronic leak detector, is a vital part of your routine maintenance program, and will prevent so many issues from turning into big headaches.  Furthermore, it doesn’t take […]

Why is my LC Retention Time Shifting?

If you have experienced retention time shifts with LC, you know it can be complicated and can cause problems with quantitation if not resolved. Hopefully this post will help you navigate through troubleshooting this situation. For the purposes of this discussion, we will be discussing changes in retention on one individual column, not differences from […]

Over tightening your fittings has consequences.

If you use the correct fittings and seals in the gas chromatography system, and follow some simple steps, there is absolutely no need to over tighten any fitting to achieve a leak free seal. For almost all fittings that use seals in a GC system, whether they are ferrules, septa or o-rings, the tightening process […]

Using a liquid leak detection solution has consequences

We have been warning about the consequences of using liquid leak detection products for years (see Blog).  These products, like Snoop, contain a whole host of compounds that can easily contaminate your GC system if you have a leak.  The solution can enter the leak site by capillary action, and is very hard to remove, […]

Discovering Analyte Breakdown On-Column

I completed my winter internship at Restek and my main task was to expand the Pro-EZGC libraries. So I created a library for Nitrosamines on the Rxi-1301Sil MS and while acquiring data we noticed a foot on a couple of my peaks. I attempted to translate the simulation to a column with the same phase, […]