Tag Archives: Gas Chromatography
Recently the American Chemical Society (ACS) held a five day intensive course on Gas Chromatography (GC). Gas Chromatography is used for DUI blood testing right here in Pennsylvania and around the country. Any DUI lawyer worth his/her salt should be well versed in how Gas Chromatography works and how it can yield erroneously high blood [...]
read more »
I have blogged a lot on Blood Testing for DUI and specifically Gas Chromatography for alcohol (ETOH) or drugs of abuse testing used in DUI prosecutions. Some people ask: Justin, your posts are so hyper-technical, why do you post such detailed stuff? When you are facing a Pennsylvania DUI, possible consequences include jail time, [...]
read more »
When tall and skinny is always beautiful? Fundamental principles of gas chromatography
March 31, 2010 by Justin McShane
It is true. They say beauty is in the eye of the beholder. Every year they have the world’s ugliest dog contest where invariably the reporters report on this event and blast the picture of the world’s ugliest dog all over the internet. Invariably comments come from all across the world that the dog isn’t [...]
read more »
How do they make the squiggly lines turn into a magic number: Area under the peak
March 29, 2010 by Justin McShane
One of the aspects of my job that I really enjoy is explaining the science of Blood Alcohol Concentration and/or reported levels of Drugs of Abuse to normal everyday folks, judges, jurors, prosecutors and even fellow attorneys. One of the most common questions I get asked is in the area of gas chromatography. Just yesterday [...]
read more »
OK so you followed our recent series on the Carry-Over Effect problem that can lead to inaccurate Blood Alcohol Content results in the posts: A large problem in Gas Chromatography: No uniform standard for GC run position or composition The Carry-over Effect: Lack of Blanks between tests leads to false positive or inflated BAC results [...]
read more »
In analytical chemistry for ETOH and Drugs of Abuse determination, it is very true that the matrix is all around us but truly is ignored
March 15, 2010 by Justin McShane
Keanu Reeves in the movie The Matrix noted that the matrix is all around us, you just haven’t chosen to see it. He had no idea that his statement would hold true in analytical testing for ETOH and drugs of abuse testing in DUI prosecution as well. The matrix is the substrate form which we [...]
read more »
I have posted before on Gas Chromatography and its principles. Gas Chromatography and why is it is so important to Pennsylvania DUI arrests Crimping a Headspace Vial in Gas Chromatography: How not putting the "lid on the jar" can lead to disaster in a DUI case A large problem in Gas Chromatography: No uniform standard [...]
read more »
If he was an analytical chemist or a DUI defense attorney he would say “Show me the separation!!”
March 8, 2010 by Justin McShane
Who can forget Cuba Gooding Junior in the movie Jerry McGuire shouting “SHOW ME THE MONEY!”??? If he was an analytical chemist or a DUI defense attorney facing a purported result from a Headspace Gas Chromatograph with a Flame Ionization Detector, he would yell: “SHOW ME THE SEPARATION!!!!!!” Well, that is one of the things that a [...]
read more »
The Carryover Effect: Lack of Blanks between tests leads to false positive or inflated BAC results
March 3, 2010 by Justin McShane
Imagine. You go into your doctor’s office for a routine physical. As part of that routine physical, the doctor takes your blood. You come back two weeks later where the doctor delivers the single worst sentence you have ever heard in your life: “I’m sorry but you have cancer.” Then comes ever worse news from [...]
read more »
Why saying the sample was run on a gas chromatograph is nearly meaningless
February 8, 2010 by Justin McShane
Saying the sampling was done on a Gas Chromatograph is like saying that you won a car. Both description are useful in that they help differentiate. In the case of all vehicles, it is useful to distinguish cars from trucks or motorcycles. Whereas in the case of chemical testing, it is useful to distinguish gas [...]
Attorney Profile on TheMcShaneFirm.com
Justin McShane on Avvo
Justin McShane on FaceBook
Justin McShane on Google+
Justin McShane on Justia
Justin McShane on LinkedIn
Justin McShane on Super Lawyers
Justin McShane on Twitter
National College for DUI Defense
Videos by Justin McShane