From: rwilson@Xenon.Stanford.EDU (Randy Wilson)
Subject: Hair testing article in C&EN
Originator: rwilson@Xenon.Stanford.EDU
Organization: Computer Science Department, Stanford University.
Date: Mon, 13 Apr 1992 20:40:15 GMT

My roommate, a physical chemist, found this article in the March
edition of Chemical and Engineering News, a technical magazine for
chemical engineering.  He said he was very unimpressed by the column,
which had amazingly little technical, useful information given the
readers of the magazine.

I'm interested in some other points raised.  I don't understand why
they don't mention the tests already in use by the FBI and <some
company>?  The idea of hair soaking up MJ smoke is interesting also,
although I wonder if the writer likes to rub money in their hair.  It
seems this problem is easily solved by testing for metabolites, which
won't be hanging around in the air.  Also, it seems like a very
important area of research for them would be the possibility of
washing the contaminants out of the hair; someone on this forum had
mentioned an alcohol-based shampoo that would probably give you ugly
split ends and frizzies, but would also wash certain metabolites out.

Reproduced here without permission.

Randy
--------------------
	Hair analysis being tested for drug detection

    People at the National Institue on Drug Abuse (NIDA) are
investigating the use of human hair as an indicator of drug use,
according to the Jan-Feb issue of ADAMHA News, published by the
Alcohol, Drug Abuse & Mental Health Administration.  The work is
proceeding at NIDA's Addiction Research Center (ARC), Baltimore, and
through extramural grants.  Coordinating the work at ARC is Edward
Cone.
    To determine the validity and reliability of hair testing for
drugs, Cone says, research is needed in two areas.  One is the actions
of drugs in hair--how hair absorbs the substances and at what rates,
and the dose-concentration relationship over time.  The second area
forresearch is the testing process--sample selection and preparation
and analytical methods.
    Scientists don't know how drugs get trapped in hair, Cone
explains, but at least four mechanisms may exist.  The most likely one
is movement from the blood into the protein matrix of the hair
follicle as it forms.  Recent research shows also that drugs bind to
hair-coloring pigments and that dark hair may capture far larger
amounts of drugs than light hair.  Also unknown is how long drugs take
to appear in hair, how long they stay there, how they decompose over
time, and whether different drugs are trapped in hair at different
rates.
    Drug testing methods are especially important, Cone notes, because
false positives can have drastic consequences for testees.  One
problem with hair in this respect is its exposure to external
contaminants.  Investigators must learn, for example, whether hair
absorbs cocaine or marijuana smoke or traces of drugs on money.  They
must also devise ways to clean the surface of hair efficiently.
    The two commercial analytical methods for drugs are immunoassay,
which is a screening test, and gas chromatography/mass spectrometry,
which is used to confirm the results of the screening test.  These
methods, normally used on urine, require liquid samples.  Thus hair
must somehow be put into solution, which may lead to contamination or
interference with the analytical methods.  The amounts of drugs in
hair samples, moreover, are minute compared with the amounts in urine.
Commercial laboratories as a rule are not equipped to analyze samples
as small as would be entailed by hair analysis for drugs, according to
Cone.  It may be necessary, he says, to develop a new generation of
tests specifically for the hair matrix.
    Still, Cone believes, hair testing has a promising future.  Hair,
he points out, is an unusual matrix "that may be able to provide a
historical record of drug use, which is something no other available
test can do."