DEA instructions for testing bills for cocaine

Michael from Muckrock sez, "Here's a science experiment that would catch the attention of high schoolers: Testing cash for cocaine traces in seven easy steps, courtesy of the Drug Enforcement Agency."

In addition to being a great way to instruct kids in proper titration technique, converting between various metric measurement units, and evaporating solvents, the DEA case is a great example in the need to exercise caution in examining noise in empirical evidence: The DEA lab ultimately advised scrapping money testing altogether since 30 percent of one sample study of "clean" money turned up a positive.

Is there a bump in your bill? Here's how the DEA tested money for cocaine — and why they stopped (Thanks, Michael!)

Notable Replies

  1. Not quite as useful as the MIT student's instructions for testing marijuana for paraquat contamination using household chemicals, back around 1980...

  2. kmoser says:

    Who cares about testing? Tell me about extraction!

  3. Does this work for both House and Senate bills?

  4. There are much simpler ways to turn a $100 bill into cocaine, you know.

  5. I was a chemist for a while.

    To understand this you need to know that:

    1. chloroform and water do not mix, they'll separate out into two layers.
    2. cocaine (like other alkaloids) is soluble in acids, not so much in bases. It's also soluble in chloroform.

    So this is what happens:

    1. extract cocaine (and other stuff) into chloroform.
    2. add water & acid; the cocaine (and a little bit less other stuff) will move from the chloroform into the water.
    3. chuck away the chloroform layer, keep the water.
    4. add base, then chloroform; the cocaine (and even less other stuff) will move from the water into the chloroform.
    5. chuck away the water layer, keep the chloroform.

    You should now have a chloroform solution of cocaine and possibly other alkaloids from the money- anything that's not an alkaloid should have been discarded at some point.

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