Archive for the ‘Drugs of Abuse’ Category

Chiral separation on a C18 column? Separation of d- and l-amphetamines, Part II

To continue my blog part 1 (Part 1:https://blog.restek.com/?p=67087) , where I have briefly discussed the importance of separating the d and l isomers to accurately identify the illicit isomer using an achiral method on a Raptor C18 column employing a pre-column derivatization technique. Today I’d like to discuss more about the matrix of interest, sample […]

Chiral separation on a C18 column? Separation of d- and l- Amphetamines, Part I

Did you know that chiral chemistry was discovered by Louis Pasteur, a French chemist and biologist in 1848? However, it took about a century to find that chirality plays a key role not only in the life of plants and animals, but also in several aspects of drug design, and both pharmaceutical and illicit drug […]

Do I smell Cannabis in the Lab?

Last week I was traveling in Europe to present seminars on practical topics like trace analysis, faster analysis and troubleshooting. During such seminars you visit companies and you always learn something.  One of the companies we visited was a company that did forensic analysis and were specialized in cannabis measurement.  My colleague already explained to […]

Spring is finally here! Unfortunately so are the ticks…

After a long and cold winter here at the Restek headquarters in Bellefonte, PA, USA it seems that spring is finally here!  It is so nice this time of year to get outside and enjoy the weather and the beautiful outdoors that Pennsylvania has to offer.   Unfortunately after a hike in the woods there is […]

Who Says There’s Nothing New Happening in GC Forensics?

From an analytical standpoint, GC/MS has been routinely used in forensics labs for decades. It was referred to as the ‘gold standard’ in analyte identification, until the ‘platinum standard’ (I’m sure some vendor coined that moniker) of MS/MS became commercially available. Even though we now have a lot of fancy new instruments at our disposal, […]

[9] What do Chromatograms tell us? Peak Shape .. Multiple Peaks for the Same Component

Chromatograms are like fingerprints.  If you can “read” chromatograms well, you often can find a plausible cause. In this series, we will show a series of GC-chromatograms that are obtained from users and discuss some potential causes for the phenomena. Then we can move into some solutions for improvement Chromatogram in fig. 1 show multiple […]

[2] What do Chromatograms tell us? Peak Shape: Reactivity initiated by sample matrix

Chromatograms are like fingerprints.  If you can “read” chromatograms well, you often can find a plausible cause. In this series, we will show a series of GC-chromatograms that are obtained from users and discuss some potential causes for the phenomena. Then we can move into some solutions for improvement. A peak shape is observed as […]

Selectivity differences for drugs of abuse when using Rxi-5ms and Rxi-5Sil MS GC columns: pendant diphenyl versus silarylene stationary phases.

Previously I had written about seeing differences in selectivity when analyzing pesticides on Rxi-5ms and Rxi-5Sil MS GC columns.  As you may remember (if you’re younger than me because I can’t remember almost anything these days!), the 5ms is a 5% pendant phenyl column and the 5Sil MS has phenyl content in the siloxane stationary […]

Pain panel causing you pain?

Particularly if you are using an AB Sciex’s iMethod™ for pain management drugs in urine, you might be noticing a shorter lifetime on your Ultra Biphenyl columns. These are challenges that we are facing and currently looking for the best solution. Since those methods in question do not contain cleanup methods such as SPE, the […]

BAC Analysis Using Hydrogen Carrier Gas: Get the Same Results at a Lower Cost!

Who doesn’t want the same thing they’re getting now at a lower cost, especially if historically that cost has only been rising? That question got me thinking about the 2012 SOFT meeting where I presented a talk about Restek’s new BAC Plus columns. A large portion of the talk focused on improving headspace chromatography of […]