Archive for the ‘Enviro’ Category

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 […]

Falling Victim to One of LC’s Classic Blunders: Mismatching Your Diluent and Mobile Phase

An early lesson most of us learn in liquid chromatography is this: Always match your diluent to your mobile phase.  Once the exams are done, if you learned this in a college course, or your manager has walked away, you start flexing this “requirement” a little to see how matched they really need to be.  […]

Two for the Price of One? Using CPP to Simultaneously Clean Pesticide and PCB Extracts

In a recently published blog, we introduced the advantages of cleaning EPA Method 8081 extracts using CarboPrep Plus (CPP) as a replacement.  The sample preparation for PCBs by EPA Method 8082 is commonly combined with the pesticides EPA Method 8081 for the extraction step then split into two portions for sample cleanup.  The logical question […]

Glycols…. Tis The Season!

Tis the season to be thinking about glycols…. Why you ask?  Well its currently winter as I’m writing this and glycols, specifically propylene glycol (PG) and ethylene glycol (EG), along with other ingredients, are used in airports for deicing planes.  Propylene glycol based fluids are more common since they are less toxic than ethylene glycol […]

Got Fast Columns? Clean Up Your 8081 Samples Using CarboPrep Plus as a Substitute for Florisil

My colleague Linx Waclaski blogged about a tale of two columns that started with the introduction of a pair of stationary phases specifically tuned for the resolution of the 20 legacy pesticides found in US EPA Method 8081(1). The story examined the gains in speed over the years as measured by the last eluting compound […]

Are You Interested in Ultrashort-Chain PFAS Analysis? Be Sure to Screen Your Solvents/Solutions for Contamination

Trifluoroacetic acid (TFA) is the perfluorinated analogue of acetic acid with the shortest possible chain length (C2) among per- and polyfluoroalkyl substances (PFAS). Together with perfluorinated C3 compounds, they are defined as ultrashort-chain PFAS. C2 and C3 PFAS are ubiquitous and very mobile in global aquatic environment including rain, snow, river, and even ocean. TFA, […]

A Tale of Two Columns (CLPesticides and CLPesticides2)—Part IV: Fast 8081 Method Using GC Accelerator Kit

The moment has finally come to see how we can use the GC Accelerator to get the most horsepower for your 8081 analysis.  If you’ve been following this blog series, you will remember that in Part II, I talked about ways to make your runs faster.  I also showed you our previous fast “7 minute” […]

TO-15 + PAMS + TO-11A = China’s HJ759 + PAMS + HJ683 part 2: Deans switching and TO-15/PAMS

In a previous blog (TO-15 + PAMS + TO-11A = China’s HJ759 + PAMS + HJ683) Jason Herrington mentioned a dual column MS/FID setup for China’s combined HJ759 + PAMS + HJ683 method. While this could be done with a simple Y splitter (such as https://www.restek.com/catalog/view/1983), a more elegant solution is to use a microfluidic […]

A Tale of Two Columns (CLPesticides and CLPesticides2)—Part III: Using the GC Accelerator Kit for Dual Column Analyses

In my previous two blogs (Part I and Part II), I mentioned the use of Restek’s GC Accelerator Oven Insert Kit (cat. #23849) for making your methods even faster.  The GC Accelerator kit was originally released with the intent of being used with an Agilent GC-MS system; however, this same kit can also be used […]

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 […]