Archive for 2019

3-MCPD blog part 2: How hot we can go with inlet and can we use regular split/splitless inlet?

In my last blog, I (hopefully!) made a case that switching to split injection for analysis of 3-MCPD esters is a viable option. Now I’d like to show that if we stick to split, we can also use much higher temperatures and if we can do that, we can also use regular split/splitless inlet. To […]

This Valentine’s Day is all about QUICK connections…

This year, you do not have to be in a long-term, committed relationship in order to embrace Valentine’s Day. In fact, this year is dedicated to “QUICK connections.” You say WHAT???? Check out the following video and you will understand:

Choosing the right dispersive SPE for GC-MS/MS analysis of celery

I’ve recently started experimenting with QuEChERS extractions for pesticide analysis. The available options are overwhelming, especially when it comes to dispersive solid phase extraction (dSPE) for the cleanup. For starters, I’ve been looking at the smaller volume dSPE (2 mL, summarized in Table 1), because I didn’t want to waste the raw material, solvents and […]

What are GenX and PFBS? Why are they important in PFAS analysis?

Analysis of PFAS (per- and polyfluorinated alkyl substances) has been a hot topic for envoironmental labs for the last several years. Currently there are two C8 based PFAS compounds (PFOA and PFOS) with a health advisory level of 70 ppt in drinking water announced by the US EPA. In 2018 at the National Leadership Summit, […]

Limitations of Alumina: What you should NOT inject on alumina / Al2O3 columns

Alumina (Al2O3) capillary PLOT columns have been available for about 35 years. They are best suited for separation of C1-C10 hydrocarbons and especially the C1-C5 range. The alumina has unique selectivity making it possible to separate all the unsaturated hydrocarbons at temperatures above ambient, see figure 1. While its an excellent choice for unsaturated hydrocarbons, special attention is […]

Trade in Splitless for Split: Faster Speed & More Miles Analyzing 3-MCPD / Glycidyl esters

In my recent work with analysis of 3-MCPD and glycidyl esters, I reviewed the available methods by AOCS and they list splitless or pulsed splitless injection. Splitless injection theoretically transfers all of the sample onto the column, allowing the analyst to achieve trace levels of detection. However, there are limitations. Both splitless hold-time and focusing […]

SPME Fundamentals: A Look into Incubation and Extraction Temperatures

Being fairly new to anything comes with some good lessons learned. My recent foray into Solid Phase Microextraction (SPME) has been a lot of fun, but I’d be lying if I said it has not been frustrating, complete with some face-palming moments.     In this series, we are going to take you on a […]

Sorry for the delay. Here is your chromatogram with and without the PFAS Delay Column.

Sometimes I hear this from customers: “I don’t need a delay column. I haven’t had any trouble without it so far.” It might be true. You may not have any issues without the delay column, especially when your samples are, for example, highly PFAS contaminated soil samples because the interference is too small to affect […]

Cannabis Residual Solvent Method Development Made Easy with Free Modeling Software

In a typical cannabis testing laboratory, finding time and resources to improve or develop methods can be scarce.  Even in our own applications group, finding time to “quickly” generate data can be a challenge with multiple projects taking place at the same time.  However, there’s a tool that can help make this process more efficient […]

Does your cannabis lab need a Residual Solvents standard? Look no further, friend!

So, we got the news. Cannabis labs and application chemists are sick and tired of residual solvent standards in DMSO. Instead of continuing to offer you something that can be difficult to work with, we put our heads together at Restek to offer you a new RSA standard in N,N-Dimethylacetamide (DMA)! Not only is this […]