Archive for the ‘GC/MS’ Category

Rxi-624Sil MS Pro-EZGC Library: 591 Compounds to Choose From

Five years ago Chris English showed in his blog post “I Can’t Drive 55” — The Pure Power of EZGC all 233 compounds that were in the Rxi-624Sil library. While that is a lot, we didn’t want to stop there. This weekend we added over 350 new compounds with various functionalities – e.g. alcohols, aldehydes (first time […]

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 […]

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 […]

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 […]

Should I use LC or GC for my analysis?

Although most analysts already know which approach they need to use for analysis, this is occasionally a topic of discussion.  While this blog post is not meant to give an absolute answer for each specific application, I hope to provide some tips to steer you in the general direction towards a solution, if this is […]

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 […]

Troubleshooting Injection Volume Variation in the Concurrent Solvent Recondensation – Large Volume Sample Injection Technique

I’ve started receiving a number of questions about the large volume injection technique called Concurrent Solvent Recondensation – Large Volume Sample Injection. Most recently, a question came through the Tech Service group about injection volume variation. I had encountered a similar problem when working on the 50 µL injection for the combined 1,4-Dioxane and Nitrosamines (EPA […]

New Custom UCMR4 Standard for EPA Method 530 on the Rxi-5Sil MS

We recently stocked custom EPA Method 530 standards made specifically for labs participating in Unregulated Contaminant Monitoring Rule 4 (UCMR4). Quantitative Certificates of Analysis with Data Packs are available for each item. Email csreps@restek.com or phone 800-356-1688 ext. 3 to place your order (items are not available at Restek.com). EPA Method 530, the Determination of Select Semivolatile […]

EPA Method 541 on the Stabilwax Column

I recently posted some chromatograms for our new EPA Method 541 UCMR4 Standards, and wanted to focus on the column in a separate post. EPA Method 541 was developed on a 30m x 0.25 mm ID x 0.50 µm wax column from another manufacturer. I used the Stabilwax because it is a relatively low bleed […]