Archive for the ‘Air’ Category

Making a TO-15 Working Standard: Part 2 How-To Video

Last time we learned that in order to make a TO-15 working standard from our stock standard we need to determine our stock standard concentration, canister volume, stock standard injection volume, and final canister pressure. We covered how to go about deriving all of the aforementioned, the associated math, and I even provided you with […]

Making a TO-15 Working Standard: Part 1 – The Super Standard Calculator – V2.01

We already learned how to calibrate our TO-15 system, what our concentration units mean, and how to properly read our vacuum gauge while pressurizing samples. We are clearly going out of order here, because I have never covered how to prepare a working standard (necessary for calibrations) from a stock standard. Therefore, the following multi-part […]

Two Detector Solution to Analyzing Sulfur

Dan Li, Katarina Oden, Chris English, and Jason Herrington Sulfur compounds are reactive, corrosive to pipes, and destructive to catalysts in petroleum refineries. Sulfur emission are strictly regulated globally. When released into the atmosphere sulfur dioxide converts to sulfuric acid resulting in adverse effects on human health and the environment. Sulfur detection is found useful […]

“Absolute” Pressure (psia) vs “Gauge” Pressure (psig)

Here is the scenario: You have just received your brand new Ashcroft Test Gauge. Why??? Because you know that the gauge on your canister is not accurate enough for making reliable quantitative dilutions. You notice that your brand-spanking-new Ashcroft Test Gauge is not reading zero, like so: Now you are starting to FREEAAK OUT!!! Because […]

Concentration Units for Air Folks

A couple of customers have recently asked about standard concentrations and converting from ppmv to mg/m³. Honestly, I have no clue how I have never blogged about this subject, especially considering how fundamental and critical this topic is. So here we go: Air concentrations at ppm are parts per million by volume and should therefore be […]

NJDEP-SRP Low Level TO-15 Series: Part 6 – Carryooooooover…

I recently received some feedback on the previous posts in this blog series and was asked the question “what kind of carryover am I seeing?” The truth of the matter is that I struggled to answer this question. I believe this question needs to be qualified a little bit in order for me to answer […]

NJDEP-SRP Low Level TO-15 Series: Part 5 – Method detection limits…

If you recall from part 1 of this blog series, NJ LL TO-15 listed MDLs as being one of the items they modified from U.S. EPA Method TO-15. HOWEVER, the only “modification” I see made is that NJ LL has outlined “specific criteria that the laboratory must meet regarding the MDL and an MDL study […]

NJDEP-SRP Low Level TO-15 Series: Part 4 – How to calibrate your system Joisey style… with no digression

In the last installment of this series, we talked about optimizing the internal standard (ISTD) responses on the Markes CIA Advantage™. This is a critical step on the road to meeting the NJ LL TO-15 calibration criteria of a 5-point curve from 0.2 to 40 ppbv, for most of the target analytes. I say “most,” because […]

NJDEP-SRP Low Level TO-15 Series: Part 3 – How to calibrate your system Joisey style… but first I shall digress on ISTDs

Last time, I showed you how well the Markes CIA Advantage™ and the Rtx®-VMS concentrate and separate the volatile organic compounds (VOCs) of interest for NJ LL TO-15. Next on the agenda would be calibrating our system (i.e., preconcentrator-GC-MS). NJ tells us to calibrate our systems with a minimum of 5 points (more allowed) and […]

NJDEP-SRP Low Level TO-15 Series: Part 2 – NJ requires a specific set of 63 VOCs

As discussed in previous blogs, the U.S. Environmental Protection Agency (EPA) Method TO-15 is applicable to a subset of 97 VOCs that are from the list of 189 hazardous air pollutants (HAPs) included in Title III of the Clean Air Act Amendments; however, only a few laboratories are analyzing all 97 components. Most laboratories are […]