The stable isotope question was not so much if it the “tablets” contained any Viagra or if there was a given or unique stable isotopic signature of Viagra as made by Pfizer. The initial question was if tablets that look like the real thing made by Pfizer and were packaged like Pfizer package the real thing could be easily and quickly distinguished from the real thing made by Pfizer. Yes, they can.


As it so happened, PCA of HNCO isotopic signature tightly clustered all the Pfizer samples (5 different batches purchased from 5 different suppliers). Pfizer must have the entire production process pretty much tightly sewn up. The counterfeit stuff did not even make it inside the 95% confidence ellipse based on Hotelling’s T^2.


Never one to trust anything or anybody unchallenged including myself, we asked a colleague to run all samples in a blinded fashion on his shiny expensive Orbitrap for API and impurities. He also could clearly distinguish between the genuine Pfizer product and the counterfeit but it took him much longer sample-prep- and analysis-time-wise.



From: Stable Isotope Geochemistry [mailto:[log in to unmask]] On Behalf Of Seth Newsome
Sent: 31 March 2020 18:44
To: [log in to unmask]
Subject: Re: [ISOGEOCHEM] [External] [ISOGEOCHEM] Your weirdest or funniest isotope samples?



Hi Wolfram...


I have a methodological question... Would measuring the isotopic composition of Viagra be the best way to test if it’s the real stuff?



Seth D. Newsome

Associate Professor, Biology

Associate Director, CSI

University of New Mexico

Department of Biology

Albuquerque, NM 87131


[log in to unmask]

On Mar 31, 2020, at 11:40 AM, Wolfram Meier-Augenstein (pals) <[log in to unmask]> wrote:

  UNM-IT Warning: This message was sent from outside of the LoboMail system. Do not click on links or open attachments unless you are sure the content is safe. (2.3)

Not really weird but certainly challenging:


Urine of neonates and preterm babies for energy expenditure determination using  the doubly-labelled water method.


Breath of neonates and preterm babies.



Other “oddities” included:


Lacustrine detritus from Antarctic dry valleys.


Soft tissue, axial skeleton, and spicules of gorgonians.


Viagra; purely for scientific reasons (to detect counterfeits); honestly.


Military explosives.


Hair and nails of Peruvian mummies.


Chaboutier Chateauneuf-du-Pape wine.








Prof. Dr W Meier-Augenstein, CChem, FRSC

Stable Isotope Forensics & Analytical Sciences


School of Pharmacy & Life Sciences

Robert Gordon University

The Sir Ian Wood Building

Garthdee Road

AB10 7GJ


*     [log in to unmask]


Stable Isotope Forensics book, 2nd edition:




From: Stable Isotope Geochemistry [mailto:[log in to unmask]] On Behalf Of Marilyn Fogel
Sent: 29 March 2020 21:30
To: [log in to unmask]
Subject: [External] [ISOGEOCHEM] Your weirdest or funniest isotope samples?


CAUTION: External sender. Do not click on links or attachments unless you expect them from the sender and know it's safe!
If in doubt please contact the Helpdesk: [log in to unmask]                  +44 (0) 1224 262777


Good afternoon to the isolated isotope geochemists of the world,


In addition to working on “regular” papers, I’d like to assemble an essay/blog this week about “weird, wacky, and funny” isotope samples. In my time, I’ve had several candidates.


Please send me yours! A paragraph on the context or a few sentences would help. Let me know if you’d like to be identified—or not.


This could be fun in itself.


Marilyn Fogel


“Always do right. This will gratify some people and astonish the rest.” Mark Twain


Follow my new blog at


Dr. Marilyn L. Fogel, 

Distinguished Professor and Wilbur W. Mayhew Professor of Geo-Ecology

Director of the Environmental Dynamics and Geo-Ecology Institute (

Dept. of Earth and Planetary Sciences

University of California Riverside

900 University Ave.

Riverside, CA 92521

Phone: 209-205-6743


Robert Gordon University has been awarded a TEF Gold award for the quality of its undergraduate teaching and learning, placing it in the top 20% of Universities in the UK

Robert Gordon University, a Scottish charity registered under charity number SC 013781.

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