Archive for 2011

Join the Coalition and Strike a Blow for Resolution!

The Coalition Against Coelution (CAC) stands for One Compound, One Peak, regardless of class. Speak out about the critical separations that matter most to you, and the tools you use to overthrow the oppressor of coelution. We’ve already looked at GC column parameters, serially-connected LC columns, and a software tool (hey Jack, what about EZ […]

Searching for the Holy Grail – LC Separations of Important PAHs and Their Interferences at RAFA 2011

Julie Kowalski is presenting her poster at RAFA 2011 today on PAH separations with serially-linked LC columns, similar to what was reported in a previous blog.  As you can see from the photo below, she is explaining her results to our very own Jaap de Zeeuw.   I guess she figures if a GC guy can […]

Chromatography and “Color Writing” in Prague – Coalition Against Coelution Seen at Lennon Wall and RAFA

The word chromatography, or “color writing”, originated from Mikhail Tsvet, and was first described in his separations of plant pigments (e.g. chlorophyll, carotenes, xanthophylls) on a calcium carbonate column with organic solvent elution. Here in Prague for the 5th International Symposium on Recent Advances in Food Analysis (RAFA 2011), my colleague, Julie Kowalski, and I […]

Free EPA Meeting! New technologies, techniques and quality assurance

Last week I attended the 21st Annual Quality Assurance Conference hosted by EPA region 6.  I really love attending this meeting because of the relaxed atmosphere, the quality of the talks, and no registration fees.  Talks are in one hour time slots, so it really lends itself nicely to discussions, instead of just lecture style. […]

GC Method Translation Software Used by CAC to Promote Faster Analysis Times While Maintaining Critical PAH Separations – Benzo[a]Pyrene

UPDATE:  The Coalition Against Coelution strikes another blow for chromatographic separation by offering a new version of the Method Translator and Flow Calculator.  You’ll see a brilliant series of posts soon, starting with Using the Restek EZGC Method Translator and Flow Calculator to Support Shoot-and-Dilute GC Method Development – Going from GC-ECD to GC-MS, that demonstrate […]

Comparing Rxi-17Sil MS to Rxi-35Sil MS for Critical PAH Separations

The Coalition Against Coelution charges ahead with additional GC PAH separations and now compares Rxi-17Sil MS (50% diphenyl-type with a silarylene backbone) and Rxi-35Sil MS (35% diphenyl-type with a silarylene backbone).  Note that we do a bit better with triphenylene and chrysene on the 35Sil MS, but give up a bit of resolution on the […]

The Coalition Against Coelution (CAC) and GC Method Translation for PAHs

Previously the CAC showed separations for PAHs triphenylene and chrysene, and the benzo fluoranthenes, on a 60m x 0.25mm x 0.10µm Rxi-17Sil MS (thank you Ron Stricek, once again!).  In this blog, we shorten the run time by a factor of 1.6 using column miniaturization (40m x 0.18mm x 0.07µm Rxi-17Sil MS – kindly made […]

Synthetic Stimulants Sold as “Bath Salts” Now Under Federal Control and Regulation

The United States Drug Enforcement Administration (DEA) just issued a  news release on its efforts to control three synthetic stimulants (Mephedrone, 3,4 methylenedioxypyrovalerone (MDPV) and Methylone) used in products sold as “bath salts” and “plant food”.  According to the DEA, “users have reported impaired perception, reduced motor control, disorientation, extreme paranoia, and violent episodes”, and the long-term […]

ETP Electron Multiplier for your Agilent 5971, 5972, 5973 & 5975 GC/MS

After several technical service calls in the span of only a few days and my own good and bad experiences with electron multipliers I’m prepared to offer you helpful hints for your Agilent 5971, 5972, 5973, & 5975. We first tried out an ETP on the advice of customers and it wasn’t long after that […]

How to Increase the Life Time of your GC Columns? Part II: Reducing Impact of the Matrix

Column lifetime is a function of pollution.  Pollution is a function of the amount injected on to the column. The more matrix we inject, the sooner we have to clean liners and  columns.  One way is to use more and better sample preparation, to reduce the matrix impacts. The cost for this is time, which […]