Archive for the ‘Enviro’ Category

Glyphosate and… Cannabis?

By now, you’ve likely heard of Roundup. Roundup is the trade name for the broad spectrum herbicide developed by Monsanto in 1974 and it’s one of the world’s most widely used agricultural weed killers. Roundup and other herbicides like it contain a polar organophosphorus compound called glyphosate. Glyphosate is degraded predominantly by bacteria into aminomethylphosaphonic […]

Ethylene Oxide – Storage and Stability in Air Canisters

In previous blogs (https://blog.restek.com/cyrogenic-cooling-for-air-analysis-interferences-from-n2-co2-and-o2/ and https://blog.restek.com/cyrogenic-cooling-for-air-analysis-part-2-combining-to-15a-and-ethylene-oxide/) I’ve talked about a combined ethylene oxide (EtO) and TO-15A method, focusing mainly on the chromatography and the use of cryogenic cooling to achieve separation of EtO from the several possible critical coelutions. However, it doesn’t matter how good the chromatography is if you can’t get your sample to […]

Using EZLC to adapt an LC pesticide method for lower pressure

  Our most popular and successful LC column for the broadest range of pesticides is the Raptor ARC-18 column. We are able to retain, provide good separation and peak shape even for many of the more polar pesticides. Whether your matrix is a food, agriculture crop or a cannabis product, the Raptor ARC-18 will probably […]

Solid Phase Extraction: Separation is the Foundation of this Preparation!

In a previous post, we made the case that the foundation for analytical separations is sample preparation.  In this post, we would like to talk about how it works the other way around, too!  Separation can actually be the foundation for sample preparation.   In particular, we would like to talk about how solid phase extraction […]

Modifying QuEChERS for complicated matrices- Soil and Sediment

In previous blog posts for this series on QuEChERS, we discussed QuECHERS dSPE Selection, Modifying QuECHERS..-Dry Samples, Modifying QuEChERS..-High Fat Samples, and Modifying QuEChERS..-High Sugar & Starch. Once again, I suggest using the following documents from the official QuEChERS website (QuEChERS.com), maintained by CVUA Stuttgart: For Extraction (Stage 1): https://www.QuEChERS.com/pdf/reality.pdf For dSPE Cleanup (Stage 2): […]

The New U.S. EPA Method TO-15A Blog Series-Part 6: Calibration Curve Fits

Our last several blogs covered the numerous ways to help clean up lab air to meet the new TO-15A guidelines for canister blanks. Absent from the previous blogs was how we were getting quantitative numbers, which is important given the new calibration guidelines in TO-15A. The original TO-15 method only mentioned using an average response […]

The Foundation of Separation is Preparation

Restek is known as a leader in the field of chromatographic column technology.  The idea is built into our very identity – resolution technology is at the heart of Restek.  We also believe that proper sample preparation sets chromatography up for success, though, by reducing the incidence of confounding results and prolonging the lifetime of […]

The New U.S. EPA Method TO-15A Blog Series-Part 5: Humidification

In the previous blog (https://blog.restek.com/the-new-u-s-epa-method-to-15a-blog-series-part4-clean-lines-for-clean-air/) I left off with our system at or under the 20pptv limit required by the new TO-15A method after replacing and moving our air fill line. Once you’re sure of your air quality and the cleanliness of your lines the next step is filling and humidifying your canisters, and if […]

Modifying QuEChERS for complicated matrices- High Sugar & Starch Samples

In previous blog posts for this series on QuEChERS, we discussed QuECHERS dSPE Selection, Modifying QuECHERS..-Dry Samples and Modifying QuEChERS..-High Fat Samples Once again, I suggest to use the following from the official QuEChERS website (QuEChERS.com), maintained by CVUA Stuttgart, these specific documents: For Extraction (Stage 1): https://www.QuEChERS.com/pdf/reality.pdf For dSPE Cleanup (Stage 2): https://www.QuEChERS.com/pdf/cleanup.pdf References […]

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 […]