Status:
Advanced ReviewerMember since: 2018
Organization: Airzone One Ltd
Great! Would not go back to our old column!
Application Area: PAH Analysis
"The column performs as advertized. Separation is good and peak tailing is minimal. The need change or trim the column is greatly reduced meaning less downtime and less money spent on new columns."
Status:
ReviewerMember since: 2019
Organization: UNC-Chapel Hill
The best column to analyze large mixtures of PAHs.
Application Area:Analyze PAHs in cookstove emissions
"I was tasked to do all of the GC-MS analysis for a new project looking at cookstove emissions in Rwanda, and I have never analyzed smoke emissions before with high levels of PAHs. I knew based on limited research that I could not effectively separate most PAHs with my standard reversed-phase 30m columns so I phoned Restek and purchased a 40m x 0.18mm x 0.07 um column. After months fruitlessly trying to get it to work, I gave up. The diameter and particle size for this column was too much pressure for my GC-MS, and I could never analyze consistently. I decided to switch to this 60m x 0.25mm x 0.10 um knowing it would be a longer analysis time but it shouldn't have a crazy high inlet pressure. Almost instantly all of the problems I was having with the 40m column were solved. With a little tinkering from the Restek literature methods, I was able to produce very sensitive standard curves for the EPA-16 PAHs within a few days of buying the column. At this point I've bought at least 6 of these columns over the last 4 years of the project. On average I get about 400 sample runs before the bleed is too high and I throw them out. But that actually is impressive. Each of my runs are 65-min methods with a bake time of 20-min at 350C. With those harsh conditions, combined with smoke extract, you'd expect the column to get nasty quickly. But I find it maintains its flexibility very well over months of running, and it holds up far better than the Rxi guard columns I concomitantly use with a temperature rating of 350C. Typically I go through 2 guard columns when I use one of these. The only tricky m/z to separate is 252.0, but that was expected based on Restek literature. Everything else works great. The only time I've ever had significant breakdown of the column lining is when the guard snapped at the beginning of an overnight run, so the regular column was exposed to air at high temperatures for 16 hours. I highly recommend this column for PAH analysis, and if you are using cleaner samples my guess is you'll average over 500 samples per column. I also do not recommend taking a chance on the 40m column unless you have a much newer GC-MS that can handle higher pressures. Both of my GC-MS's were purchased in the early 2000s and the inlets have a difficult time with the 40m column at temperatures above 320C at 1 mL/min flow."