Archive for the ‘Pesticides’ Category

Upcoming revisions to three wastewater methods reviewed at NEMC 2017

Monday morning, representatives from the EPA’s wastewater office reviewed the significant changes for the three major GC wastewater methods: 608.3, 624.1, and 625.1. The overarching goals were to modernize the methods and bring the language and QC requirements in line with the methods from the drinking water and hazardous waste offices. The methods have been […]

EPRW: European Pesticides Residue Workshop in Sunny Cyprus

                                    Just wanted to let everyone know that we have published our presentations we presented at EPRW (European Pesticide Residue Workshop) last month in Limassol, Cyprus. It was a great meeting in a beautiful location. It was a pleasure to […]

Pesticide analysis for cannabis flower: method and data overview

Pesticides in cannabis has been a hot topic lately and we have been getting many requests for help with this analysis. We did work on pesticide residue testing in cannabis about 6 years ago. At that time, we were limited to testing our methods with a small amount of seized material. Recently, we have been […]

Split Injection Makes for Easier Polar Solvent GC Work versus Splitless Injection

As anyone who’s doing QuEChERS knows, analyzing acetonitrile extracts on nonpolar GC columns (like Rxi-5ms, e.g.) using splitless injection can be problematic because of the classic solvent – stationary phase mismatch.  To avoid split peaks we usually have an initial GC oven temperature slightly above the 82°C boiling point of acetonitrile (MeCN), but this causes tailing […]

Shoot-and-Dilute GC – Practical GC – The Column

Check out my recently published articles in LCGC – The Column on Shoot-and-Dilute GC (split injection GC), where I outline the benefits of this technique through recently collected experimental data in my lab at Restek.  I’m two articles into my Practical GC series, with another one soon to be published.  This is a continuation of other split injection work […]

The “Breakdown” of Endrin and DDT for Non-Environmental Chemists

As the title makes clear, this post is aimed more at non-environmental laboratory personnel who are not familiar with US EPA methods.  If you are one of those environmental lab gurus who shudders at the sound of a “pesticide degradation check”, this is probably stuff you already know. Anyways, for the rest of you, you […]

Changing from helium to nitrogen carrier gas in gas chromatography while maintaining separation efficiency and analysis time

In two recent ChromaBLOGraphy posts (see links below) I described the experimental implementation of an idea Jaap de Zeeuw had to use nitrogen carrier gas for GC while maintaining the same separation efficiency and analysis time as what could be achieved by helium carrier gas. Wait, that’s impossible, right?!  Not if you go from a […]

Fast gas chromatographic residue analysis in animal feed using split injection and atmospheric pressure chemical ionization tandem mass spectrometry

In a recent ChromaBLOGraphy post I mentioned that we are doing a campaign on “shoot-and-dilute GC”, also known as split injection GC, at RAFA 2015. A paper just published by Tienstra, Portolés, Hernández, and Mol used split injection with APGC for pesticide and other residue analysis in animal feed to achieve many of the benefits we’ve been […]

7th International Symposium on Recent Advances in Food Analysis (RAFA)

The 7th International Symposium on Recent Advances in Food Analysis, better known in short as RAFA, starts this week in Prague, The Czech Republic.  This is my tenth anniversary for this biennial meeting, where the organizer, Jana Hajšlová, invited me to give the lecture, Using the QuEChERS Sample Preparation Method and GCxGC-TOFMS to Determine Pesticides […]

Phthalate-Free Personal Care Products?

In her recent ChromaBLOGraphy posts, Minimizing Phthalate Interferences Using the Rtx-CLPesticides/Rtx-CLPesticides2 Columns and EPA Regulated Phthalates FREE?, my colleague Dan Li pointed out the ubiquitous nature of phthalates in our world because of their widespread use in plastic consumer products, and that phthalates likely have adverse human health effects, including as endocrine disruptors.  Any of […]