Posts Tagged ‘pesticides’

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 […]

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): […]

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 […]

Modifying QuEChERS for complicated matrices- Dry Samples

Before getting in to this discussion, I recommend reading my previous blog post first regarding classical applications for methods based on Quechers. https://blog.restek.com/quechers-dspe-selection-which-one-is-best/ QuEChERS methods were originally written to analyze pesticides in fruit and vegetable matrices, most of which have high water content and low fat content. More recently, the technique has been used for […]

Quechers dSPE selection- which one is best?

Method development for Quechers sample cleanup can be a complicated task. Not only does the analyst need to make sure their analytes of interest can be recovered, but the matrix interferences must be removed enough to make the quantitation possible and reliable. It makes sense that selecting the best dSPE products is highly dependent on […]

What’s in a name? A C18 by any other name would not be the ARC-18

You have probably read or been told numerous times and in numerous ways that not all C18 columns are the same. And that is very true. Particle morphology, bonding chemistry, and add-ons like end capping all influence the retention and selectivity of this workhorse LC phase. At Restek we have an interesting C18 phase that […]

355 compounds have been added to the Rxi-XLB library for the Pro EZGC Chromatogram Modeler

The Rxi-XLB is a popular column for the analysis of PAHs and persistent environmental pollutants (POPs) such as PCBs and Pesticides. We’ve updated the library of 209 PCB congeners, expanded the PAH library to 47 compounds (including 6 deuterated isotopologues commonly used as internal standards or surrogates), and added the 203 compounds in the GC Multiresidue […]

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 […]

Need Help with QuEChERS: #AskRestek Twitter Q&A session

Just wanted to let everyone know we will be hosting a #AskRestek Twitter Q&A session about QuEChERS next week at 3:00 p.m. EST (12:00 noon PST) on Tuesday, May 3. QuEChERS is a great approach for sample preparation with lots of benefits. It is also very flexible which is nice but that can also make […]

The Most Useful Pesticide Standard Ever…monitoring GC inlet “dirtiness”

I have spent most of my time over the past several years testing pesticides and there is one standard that I simply can’t live without…QuEChERS Performance Standards Kit. It is based on a really interesting article* on analyte protectants with a few compounds added. The standard has 40 compounds housed in three vials for long […]