Archive for 2011

EPA 8270 with Appendix IX: 145 Semivolatile Compounds in 17 Minutes

  Using an Rxi-5Sil MS 30m x .25 x .25 and a Restek Premium single taper WITH WOOL inlet liner, I ran an eight point 8270 calibration including the Appendix IX compounds. The calibration range was 0.5 µg/mL – 120 µg/mL, with individual points at 0.5, 1.0, 5.0, 10, 20, 40, 80, and 120 µg/mL. The attached […]

The Dynamic Duo is Here: Introducing a New Blood Alcohol Column Set!

*Cue theme music* Although I generally don’t highlight specific products in the blogs I write, I’m going to break my pattern to introduce the new blood alcohol (BAC) column set. Over the past several months, I’ve had the great luck to be able to work closely with our team of polymer chemists and engineers throughout […]

Modified EPA SOP RSK-175 Using a Teledyne Tekmar Purge and Trap Concentrator

The US is in the midst of a “gas” rush from Colorado to New York State. Gas containing shale sites will become common vernacular with names such as, Barnett, Devonian, Marcellus, Utica, Antrim, Haynesville, and New Albany. Several regions have what are known by the energy companies as stacked plays, that is, areas where two […]

How Cool is PFTBA: Tuning Your MS in the Challenger Deep

Not only is perfluorotributylamine a perennial favorite for tuning mass spectrometers, it looks like the flux capacitor! But that’s not all. Perfluorocarbons (PFCs), including PFTBA, are used in blood substitutes. Severe blood loss compromises circulation, an effect that can be countered through volume-replacement therapy. However, circulation does the patient little good if what’s in the […]

How to Increase the Life Time of your GC Columns? Part III Gases, Flows and Practical Operation

For operation of GC columns a carrier gas is required.  In the first blog of this series we zoomed into the importance of using clean carrier gas.  We also have a choice on type of carrier gas. Mostly Helium is used, because of its high optimal velocity and inertness but that gas is loosing its […]

How to make a good fused silica seal using PressTight type connections

Column coupling remains a very interesting topic. Whether its for connecting a guard column, a retention gap, column extension, transfer line s to one or multiple detection systems, or just repairing a broken column.  For fused silica coupling the PressTight has found wide application.  For ease-of-use the universal PressTight was developed. http://www.restek.com/catalog/view/370 To enhance response […]

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 […]

Even the Honey Badger cares about food authenticity

It was recently reported in Food Safety News that the majority of “honey” sold in the United States is not technically honey, because it’s been ultra-filtered to remove all of the pollen. Maybe the honey badger doesn’t really care, but consumers should. Pollen is an essential constituent of authentic honey, and is not effectively removed […]

European Food Safety Authority (EFSA) PAH4 Separated on Rxi-35Sil MS – The Coalition Against Coelution (CAC) Continues Its Dominance over Polycyclic Aromatic Hydrocarbons (PAHs)

The Coalition Against Coelution (CAC) is putting together all the pieces for you now on the most important PAHs according to the European Food Safety Authority’s Scientific Opinion of the Panel on Contaminants in the Food Chain for Polycyclic Aromatic Hydrocarbons. The PAH4, consisting of benzo[a]pyrene, benz[a]anthracene, chrysene, and benzo[b]fluoranthene, are representative of the carcinogenic […]

Effect of Source Temperature on 2,4-DNP Response at Low Concentrations

Last year, Michelle wrote a blog highlighting the effect of source temperature on peak shape and recoveries. I was having my own problems with terrible PAH peak shape on the same instrument (a 7890a/5975C with an inert source). While the inert source has a maximum programmable temperature of 350 degrees, I made sure to heed […]