Archive for the ‘Detection Techniques’ Category

Using a liquid leak detection solution has consequences

We have been warning about the consequences of using liquid leak detection products for years (see Blog).  These products, like Snoop, contain a whole host of compounds that can easily contaminate your GC system if you have a leak.  The solution can enter the leak site by capillary action, and is very hard to remove, […]

Determining Optimal LC-MS/MS MRMs: Sensitivity is NOT Everything!

LC-MS/MS using electrospray ionization (ESI) is a widely used platform for routine target analysis and quantitation. However, one big challenge faced through the use of ESI is the presence of matrix effects. So, what are matrix effects and why are they important? Simply put, when matrix components coelute with the target analytes, they have the […]

A better way to configure your EZ No-Vent GC-MS Connector Part II

Last time, I wrote a blog (here) that showed a better way to configure the EZ No-Vent in the software so that the column length didn’t need to be manipulated. I kept the volumetric flow the same, and showed different ways to minimize the negative chromatographic effects of the reduced linear velocity. Today, I’m going […]

A better way to configure your EZ No-Vent GC-MS Connector

If you are using the EZ No-Vent for Agilent mass spectrometers (cat.# 21323), you are probably tricking your instrument into working properly by inflating the length of your column in your acquisition software. If you have MassHunter, or a recent version of MSD ChemStation  (G1701EA), you don’t have to do this. Instead of configuring your […]

General (very general) guidelines to help meet GC detection limits.

Sometimes we (tech service) receive requests from customers who cannot meet detection limits when developing a new method or when trying to follow a current method. They ask for advice on how to meet these limits.  As a result, I decided to provide some (very) general guidelines that I would follow back-in-the-day when I would […]

Cassini-Huygens: 20-Year Mission Accomplished

On October 15th, 1997, the $3 billion spacecraft went on a seven year, two-billion-mile journey to study the planet Saturn along with its moons and rings. After arriving at the Saturnian system, Cassini deployed the 700-pound Huygens probe to its largest moon, Titan. At 100 miles above the surface the aerosol collector pyrolizer (ACP) and […]

Cannabis Residual Solvents Using MS Detection – I’m Not Hungry but I’ll Eat My Words Anyway

After coming back from a huge lunch at the Bellefonte Wok, a favorite Restek lunch spot, I’m completely stuffed, but I have to eat my words from a previous blog. In this blog, I made the case against using MS detection for headspace analysis of residual solvents in cannabis concentrates due to interference between the […]

GC-API-MS for BDEs with N2 at BFR2016

OK Jack, enough of the acronyms; this isn’t a word puzzle… Recently I let ChromaBLOGraphy readers know of our work on using gas chromatography (GC) with atmospheric pressure ionization (API) – mass spectrometry (MS) for analysis of brominated diphenyl ethers (BDEs) employing nitrogen (N2) carrier gas, which was presented at BFR2016 (BFR standing for Brominated […]

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 […]

High Source Temperatures and Meeting EPA Tuning Criteria

My first blog here at Restek was a demonstration of how increasing the source temperature could improve the raw response of 2,4-dinitrophenol while maintaining the relative response. Four years later I’m here with the promised follow-up on the elevated source temperature effects on tune evaluations (and making adjustments via target tuning). This blog is going to deal […]