Archive for the ‘Air’ Category

The New U.S. EPA Method TO-15A Blog Series-Part 5: Humidification

In the previous blog (https://blog.restek.com/the-new-u-s-epa-method-to-15a-blog-series-part4-clean-lines-for-clean-air/) I left off with our system at or under the 20pptv limit required by the new TO-15A method after replacing and moving our air fill line. Once you’re sure of your air quality and the cleanliness of your lines the next step is filling and humidifying your canisters, and if […]

The New U.S. EPA Method TO-15A Blog Series-Part4: Clean Lines for Clean Air

In previous blogs (Part 1, Part 2, Part 3) we’ve covered the need to use air instead of nitrogen as a fill gas, the new lower blank requirements, and how these increase the importance for very clean lab air for canister filling. We’ve shown that using high quality gas filters or generators will get you […]

The new U.S. EPA Method TO-15A blog series – Part 3: Use CLEAN air on a CLEAN analytical system!

From the start of this blog series, I have been teasing you with how to take your canister blanks from the following red trace down to the blue trace: In this post, I shall finally stop dragging it out. BUT FIRST… (Come on now, you had to have known this was coming) I shall digress […]

The new U.S. EPA Method TO-15A blog series – Part 2: Use air when analyzing air!

Last time, we left you with a teaser, how to take your canister blanks from the following red trace down to the blue trace: Before we get to that, let us back up to 2015, where both Wayne Whipple (retired US EPA) and I coincidentally presented on canister cleaning and canister blank levels at the […]

Cryogenic Cooling for Air Analysis Part 2 – Combining TO-15A and Ethylene Oxide

In my previous blog on cryogenic cooling (https://blog.restek.com/cyrogenic-cooling-for-air-analysis-interferences-from-n2-co2-and-o2/) I touched briefly on ethylene oxide (EtO) and why it may be of interest in ambient air analysis. While OSHA has a time weighted average (TWA) limit for EtO at 1ppm for an 8 hour exposure, recent work by the US EPA has shown that even low […]

The new U.S. EPA Method TO-15A blog series – Part 1: It has arrived!!!

March 2016, the U.S. EPA announced it would start updating the long overdue (i.e., not updated since 1999) Compendium of Methods for the Determination of Toxic Organic Compounds in Ambient Air Second Edition (625/R-96/010b), by soliciting public comments and suggestions on Method TO-15*. May 2016, the agency closed the open comment period and set off […]

Cryogenic Cooling for Air Analysis – Interferences from N2, CO2, and O2

Spring is already here and summer is just around the corner and soon we’ll be trying to stay cool.  For those of us doing ambient air analysis though, keeping cool can sometimes mean cryogenic cooling. While our VMS columns can easily separate the TO-15 compounds with no need for cryo cooling (see https://blog.restek.com/air-columns-part-iii-my-favorite-column-phase-for-epa-method-to-15/) there are […]

Not all 3.2 L air sampling canisters are 3 liters. Wait… what!?

The other day a customer contacted me to share the following discrepancy she has observed on several occasions: “when I collect ambient air samples with Restek 3 L canisters and collocated 3.2 L canisters from the competition, the canisters fill in the same amount of time.” Obviously this does not make sense, so I immediately […]

TO-15 + PAMS + TO-11A = China’s HJ759 + PAMS + HJ683 Part 3: Formaldehyde Sampling in Air Canisters

In my previous blog (TO-15 + PAMS + TO-11A = China’s HJ759 + PAMS + HJ683 part 2: Deans switching and TO-15/PAMS) I covered the combination of the TO-15 and PAMS (or HJ759 and PAMS) methods into a single run using a Deans Switch and FID/MS detector set up. I said that I’d revisit integrating […]

TO-15 + PAMS + TO-11A = China’s HJ759 + PAMS + HJ683 part 2: Deans switching and TO-15/PAMS

In a previous blog (TO-15 + PAMS + TO-11A = China’s HJ759 + PAMS + HJ683) Jason Herrington mentioned a dual column MS/FID setup for China’s combined HJ759 + PAMS + HJ683 method. While this could be done with a simple Y splitter (such as https://www.restek.com/catalog/view/1983), a more elegant solution is to use a microfluidic […]