Archive for the ‘CSR-LVSI’ Category

Are you experiencing helium supply issues and rising costs?

Helium supply issues are nothing new.  At Restek we have been discussing this off and on for years now.  The following articles and information are just a small selection of what is available on our website and our ChromaBLOGraphy, and are there to help you make informed decisions about alternatives to helium, and reduced helium […]

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 […]

Analysis of Halogenated Organic Contaminants in Water Using GC-MS and Large Volume Injection

I recently attended the annual meeting of  AOAC International where I presented a poster on adapting EPA method 551.1 to GC-MS by using the CSR-LVSI technique our lab has had so much success with in the past. EPA 551.1 is a dual column GC-ECD method used to measure a wide range of halogenated organic contaminants in drinking […]

Solvent Focusing – The Key to Successfully Implementing CSR-LVSI

It’s been over a month since my last post on Concurrent Solvent Recondensation – Large Volume Splitless Injection (CSR_LVSI), so I thought I would cover solvent focusing, a key element of the technique, today. The CSR-LVSI solvent peak widths are minutes larger than those seen in a typical 1 µL injection. Figure 1 shows the difference in solvent […]

Sometimes Peak Defects Are Not the Sign of a Problem

Last month, I demonstrated the feasibility of a 250 µL injection in a split/splitless injection port, using the EPA Method 521 (nitrosamines in drinking water) list. As you can see in the chromatogram below, seven of the eight peaks are nice and symetric. Peak number 2, however, shows exaggerated fronting. N-nitrosomethylethylamine is the only compound on […]

Is there a limit to the volume you can inject into an agilent split/splitless inlet?

Theoretically, the answer is no; the limiting factor of a concurrent solvent recondensation – large volume splitless injection (CSR_LVSI) is the surface area available to support a stable film of recondensed solvent. If you read my previous post, which utilized a 50 µL injection to meet lower detection limits for 1,4-dioxane and various nitrosamines, you may […]

Combine EPA 521 and EPA 522 into a Single Analysis Using a (Very) Large Volume Injection with an Agilent Style Split/Splitless Inlet

While I was at NEMC in San Antonio, I posted a teaser for my drinking water talk here on the blog. I thought I would follow-up with some details for those of you who were unable to attend (and those who did). Today, I’m going to give my final run conditions for the 50 µL injections, […]

Meet Low ng/L Detection Limits for Volatiles in Drinking Water Using Coconut Charcoal Cartridge SPE and a 50 µL Injection in an Unmodified Agilent Split/Splitless inlet – Find out how at the NEMC Drinking Water Section Thursday Afternoon

  I’ve been working on combining EPA methods 521 and 522 for a while. Both methods use the same SPE cartridge and very similar extraction procedures. In order to meet extremely low PPT detection limits required by 521 on my 7890A-5975C, I had to resort to a 50 µL injection. Generally,a special injection port such […]

Visit My E-Poster at PittCon 2013 Today (Thursday, March 21st) to See an Animation of the CSR-LVSI Mechanism

  I’ll be at my posters between 10 and 12 tomorrow morning, so swing on by if you have any CSR-LVSI questions or want to check out the animation. Room 204ABC, abstract numbers 2500-4P (EPA 522; 1,4-dioxane in drinking water) and 2500-5P (semivolatiles in drinking water). I’ve included a preview. Also, Jaap is presenting his paper, Bonded […]

Large Volume Splitless Injection for EPA Method 522: 1,4-Dioxane in Drinking Water

An abridged copy of the application has been published in the June 2012 edition of the LC|GC Application Notebook The full application note can be found here This past January, the EPA revised its 1,4-dioxane advisory, lowering it from 3.0 µg/L to 0.35 µg/L, a near 10-fold drop, and we’ve been seeing an increase in requests for […]