If he was an analytical chemist or a DUI defense attorney he would say “Show me the separation!!”

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:


Well, that is one of the things that a good criminal defense attorney who specializes in defending the citizen among us who has been accused of a DUI should always demand whenever there is a reported result from a chromatographic process.


As I posted before in Gas Chromatography and why is it is so important to Pennsylvania DUI arrests:

Chromatography is strictly and simply speaking “separation science”. It is the study of how an analyst can take a complex matrix (compound) and separate it out into its component parts.

If you can’t prove separation between like analytes, then your result means nothing.

Much like I posted before “A large problem in Gas Chromatography: No uniform standard for GC run position or composition“.  There is also no uniform nomenclature for what this is called.

I have seen it called:

  • Harrisburg DUI Lawyer verifier and resolution chromatogramResolution Control Standard
  • Separation chromatogram
  • Matrix chromatogram
  • some don’t call it anything at all (because they don’t do it)

For ETOH determinations at a minimum we need to see this proof of separation for from standards that are NIST certified values or comprised of USP grade materials (see generally:  Metrology in DUI prosecution for the importance of these concepts):

  1. acetaldehyde
  2. acetone
  3. acetonitrile
  4. ethanol
  5. ethyl acetate
  6. isopropanol
  7. methanol
  8. methyl ethyl ketone
  9. butanol

Below is an example of just such a type of proof:

Harrisburg DUI Lawyer verifier and resolution chromatogram2


-Justin J. McShane, Esquire, Pennsylvania DUI Attorney

I am the highest rated DUI Attorney in PA as Rated by Avvo.com

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Harrisburg DUI Lawyer Justin J McShane Esquire earns<br /> criminal law certification throguh NBTA

Board Certified Criminal Trial Advocate
By the National Board of Trial Advocacy
A Pennsylvania Supreme Court Approved Agency

Justin McShane

PA DUI attorney Justin J. McShane is the President/CEO of The McShane Firm, LLC - Pennsylvania's top criminal law and DUI law firm. He is the highest rated DUI attorney in PA as rated by Avvo.com. Justin McShane is a double Board certified attorney. He is the first and so far the only Pennsylvania attorney to achieve American Bar Association recognized board certification in DUI defense from the National College for DUI Defense, Inc. He is also a Board Certified Criminal Trial Advocate by the National Board of Trial Advocacy, a Pennsylvania Supreme Court Approved Agency.

2 responses to “If he was an analytical chemist or a DUI defense attorney he would say “Show me the separation!!””

  • I feel that a problem with a lot of attorneys is they used to work for the DA or they are somehow connected to someone that is associated with the judge and this has an affect on how an individuals case is handled.

  • Mike,
    That can be a legitimate concern. This is why you should always exercise the maximum amount of due diligence in investigating your lawyer before you hire him or her. Spend a lot of time on the internet and talking to other folks. The most important thing to remember is to be 100% selfish. WHO your attorney is can have the biggest impact as far as what happens to you. So, take the time and don’t settle.

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