Archive for the ‘Method Translator and Flow Calculator’ Category

Accounting for Atmospheric Pressure When Using EZGC Method Translator and Flow Calculator and the ProEZGC Chromatogram Modeler

Modern GC’s are equipped with advanced pneumatics controls, which allow for accurate control of flow rates and pressures.  In order to accurately control or calculate flow rates, atmospheric pressure must be measured by the GC, since this determines the outlet pressure of non-vacuum detectors. Restek’s free tool, the EZGC Method Translator and Flow Calculator, has […]

Optimizing Splitless Injections: Splitless Purge Valve Time

In my previous blog, I discussed optimizing inlet temperature for splitless injections.  Today I would like to discuss another critical parameter for splitless injections: splitless purge valve time.  The key feature of a splitless injection is that all the carrier gas flow is directed to the column and the splitless valve is closed during injection.  […]

Are Wax columns always used for essential oils?

My last blog examined the analysis of essential oils using GC columns with wax phases. While these columns are commonly used for natural oils, they are not the only option. Another choice that falls on the other end of the selectivity spectrum, in this case, a non or low polar; dimethyl diphenyl polysiloxane stationary phase. […]

Pro EZGC Update: Comprehensive 209 compound Library of Brominated Diphenyl Ethers and a New Column Format

While attending Dioxin 2018 in Krakow, I noticed that several academic researchers were studying  the toxicity of specific PBDE congeners not on the standard target compound list for EPA method 1614 (or the EU equivalent). Though PBDE mixtures have been phased out of production and use, the concentrations in the environment have not been declining […]

What impurities are hiding in your monocyclic aromatic solvents?

As we approach the end of the year we are indulging in a bit of nostalgia and most experts agree that reminiscing about the past is a good thing1. It makes us more optimistic and generous. Researchers also noticed that in cold rooms we are more inclined to nostalgize than if we are in a […]

A Tale of Two Columns (CLPesticides and CLPesticides2)—Part II: Gaining Speed

In my previous blog post, I gave you a little history of the CLPesticides columns.  You’ll remember that I pointed out the 24 minute run times, which were promoted as being fast at the time.  Fortunately, there are ways to attain faster runs on this column pair for standard 8081 pesticides, due to their awesome […]

FAMEs blog part 4: Struggling with using hydrogen for AOCS methods Ce 1j-07 or Ce 1h-05?

This blog a part of a series: part 1, part 2, and part 3 Recently I came across customers’ issue with AOCS method Ce 1h-05 used with hydrogen as a carrier gas and I’ve decided to look more closely into what conditions are suggested for this analysis. While at it, I looked also into conditions of methods […]

Are you experiencing helium supply issues and rising costs?

Helium supply issues are nothing new.  At Restek we have been discussing this off and on for years now.  The following articles and information are just a small selection of what is available on our website and our ChromaBLOGraphy, and are there to help you make informed decisions about alternatives to helium, and reduced helium […]

GC-API-MS for BDEs with N2 at BFR2016

OK Jack, enough of the acronyms; this isn’t a word puzzle… Recently I let ChromaBLOGraphy readers know of our work on using gas chromatography (GC) with atmospheric pressure ionization (API) – mass spectrometry (MS) for analysis of brominated diphenyl ethers (BDEs) employing nitrogen (N2) carrier gas, which was presented at BFR2016 (BFR standing for Brominated […]

Restek at BFR2016 in Toronto – APGC of Brominated Flame Retardants Using Helium and Nitrogen Carrier Gases

In only a few short weeks, I will be giving a presentation on the analysis of brominated flame retardants at BFR2016 in Toronto.  My colleagues and I used an atmospheric pressure ionization mass spectrometer with gas chromatography on an Rtx-1614  (15m x 0.25mm x 0.10µm) column to look at polybrominated diphenyl ethers (PBDEs) in various […]