Hair analysis

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A human hair under the microscope
(detail: 600 × 400 µm²)

Hair analysis , also called hair analysis , is the name for a chemical analysis of a hair sample . The hair serves as an easily accessible biomonitor in which many exogenous compounds are stored in significantly higher concentrations than in other organs. The term hair analysis itself does not provide any information about the analysis method ultimately used.

Hair analysis is particularly suitable in forensic toxicology and ecotoxicology for carrying out a retrospective analysis of the absorption of various chemical elements and organic compounds by a person over a period of several months.

In addition, hair analysis, sometimes under terms such as "hair mineral analysis" or "bioresonance hair analysis" or "radionic hair analysis", is used as an alternative medicine for various diagnostic applications. These forms of use of hair analysis are largely rejected by scientifically based medicine .

Storage of exogenous substances in the hair

Schematic structure of a body hair.
1) hair 2) skin surface 3) sebum 4) hair follicles 5)  sebum  gland

Human and animal hair store a large number of exogenous substances largely unchanged in their structure. The form of application ( oral , nasal , intravenous or inhalative ) does not matter. Once absorbed, the substances also reach the body hair via the bloodstream , which is connected to the blood vessels via the hair papillae . The fast-growing, often dividing cells have a higher metabolism than normal body cells. They therefore take up more nutrients, but also exogenous substances. Hair growth begins in the hair follicle located a few millimeters below the skin surface . The horn-forming cells bundle and keratinize into keratin fibers . They migrate upwards and form the hair shaft that pushes in the follicle to the surface of the skin. The surface of the skin is reached after one to two weeks. During the hair growth phase, some of the exogenous substances contained in the blood are also stored in the hair. As the hair grows in length, these substances come out through the surface of the skin. The hair on the head grows an average of 10 mm per month. By analyzing individual hair sections from the tip of the hair to the root of the hair, a temporal analysis of the absorption of the exogenous compounds can be carried out. In principle, this is also possible with historical hair samples.

The substances stored in the hair cannot be completely removed even by washing, tinting or other treatments. Given the high sensitivity of the examination methods used, the remaining quantities are still sufficient, for example, to prove that narcotics have been taken. The possibly very different pretreatment of the hair is problematic when quantifying elements, for example trace elements .

Analytics

ICP-MS device
GC-MS device

Various methods from trace analysis can be used as analytical methods , which are selected depending on the element or compound sought. If, for example, chemical elements such as heavy metals are to be analyzed, mass spectrometry with inductively coupled plasma (ICP-MS) or ICP-OES , or more rarely neutron activation analysis , are used. By means of laser ablation and subsequent ICP-MS, an element analysis can be carried out in sections on just one hair.

Liquid chromatography with mass spectrometry coupling (LC-MS or LC-MS / MS) and gas chromatography with mass spectrometry coupling (GC-MS or GC-MS / MS) are usually used to analyze chemical compounds, such as narcotics . Radioimmunoassays were often used in the past .

Some substances are analyzed in the form of their metabolic products ( metabolites ). For example, heroin in the body is first metabolized to 6-monoacetylmorphine (6-MAM) and then to morphine after injection . A large part of the heroin absorbed is excreted as morphine or glucuronidized morphine after several hours . A small part of the morphine and 6-MAM is also stored in the hair structure. However, the codeine contained in some medications - such as cough syrup - is also partially metabolized to morphine, so that a determination that would only include morphine does not provide any evidence for the use of heroin. That is why the non-metabolized codeine in the hair is also determined in the heroin analysis. A morphine / codeine ratio of 2: 1 is considered to be heroin abuse. If the measured morphine concentration is below 1 ng / mg (= 1 ppm ), a ratio of 5: 1 is required. If 6-MAM is detected in the hair sample in a concentration greater than 0.5 ng / g, heroin consumption is assumed, since 6-MAM is not a metabolite of codeine. In general, certain limit values ​​must be exceeded for an analyte and often its metabolites must also be detected so that the hair sample can be assessed as positive.

Sample preparation

Element analysis

When analyzing chemical elements, no special sample preparation is often necessary. The neutron activation analysis works, for example, without destroying the sample. Laser ablation can even be used to analyze a single hair section by section.

Narcotics analysis

The hair samples used for a forensic examination are preferably taken as a strand from the back of the head . In this hair region, hair growth is particularly regular. In principle, pubic , armpit , beard , chest and other body hair can also be used. The removed strand of hair is a few mm in diameter . About 30 to 50 mg of hair are sufficient for each section of hair to be analyzed. With a segment-by-segment analysis of the hair, the type and frequency of drug consumption can be analyzed via the hair sections (“drug career”). After taking the hair sample, it is prepared for subsequent analysis in a special extraction process. For example, the hair is first ground in a grinder and then dissolved in an acid before it can be analyzed. Some of the ingredients to be analyzed are extracted from the hair with methanol .

Applications

The best known and most common application of hair analysis is the detection of addictive substances and drugs in forensic medicine . While many drugs, drugs and doping agents can often no longer be detected in blood and urine after days, a large number of these substances are built into the growing hair and can thus still be detected after months. These active ingredients cannot be removed by normal hair washing or other conventional hair treatment methods. In addition to substances such as cannabis , cocaine , ecstasy or heroin , doping agents such as various anabolic steroids and nandrolone can also be detected. Even prolonged alcohol abuse or alcoholism can be detected via the metabolite ethyl glucuronide (ETG).

For the analysis of the DNA , for example for a parentage report ("paternity test"), on the other hand, only hair with hair roots is suitable , since only there cells with analytically usable material are contained.

Well-known application examples

Napoleon

By analyzing the hair of the man from Tisenjoch - better known as "Ötzi" - it was found that he was mainly vegetarian.

In 1961, a Napoleon hair sample was examined using neutron activation analysis. It was shown that he had gradually absorbed arsenic . The segment analysis of a 130 mm long strand also determined that he had consumed arsenic intermittently during a one-year phase. In addition, the approximate times could be reconstructed. Whether it is intentional poisoning or the living conditions on St. Helena is still a matter of controversy.

The result of a hair analysis published by Christoph Daum on October 20, 2000 , which he himself commissioned from the Institute for Forensic Medicine at the University of Cologne , subsequently led to termination without notice as a club trainer and to the dissolution of one that was closed for June 1, 2001 Contract as national coach at the DFB .

Hair analysis offers from commercial providers

Various clinical-chemical laboratories, (environmental) pharmacies , health food stores , alternative practitioners and commercial hair analysis institutes offer hair analysis as a service. The analysis is intended to provide information on the supply status of minerals and possible pollution with environmental pollutants ("heavy metals"). The reliability of the measurement results as well as their interpretation are doubted by science. The reasons given are the following:

  • How and to what extent the individual elements are incorporated in the hair has in many cases not yet been adequately researched.
  • So far, no or only a weak correlation has been found between the values ​​in the hair and the values ​​in other biomonitors (blood and urine).
  • So far it is largely unknown how high concentrations of pollutants in hair and possible health consequences are related. In the hair itself, the harmful substances are harmless to those affected.
  • Hair color, gender, ethnicity and age have a significant influence on the storage of foreign substances in the hair. Likewise diet, hair treatment and place of residence. The factors are not taken into account in many laboratories. Furthermore, there are no guidelines for sampling.
  • Many analytics service providers do not have any quality assurance measures .
  • There are no established “normal values” for the content of minerals and trace elements in hair, as there is not yet sufficient data for a definition.

The US Agency for Toxic Substances and Disease Registry (ATSDR) therefore only considers hair analysis to be suitable for determining the level of methyl mercury to determine the individual exposure to harmful substances.

In 2004 the Stiftung Warentest compared several providers of hair analyzes. For individual test persons, there were sometimes considerable fluctuations from laboratory to laboratory. Samples from the same anonymized person were often measured in the same laboratory with different values. Individual laboratories also reported “normal values” for the analytical results, which also differed considerably from laboratory to laboratory.

literature

  • Patricia Anielski: Long-term evidence of anabolic steroid hormones . Dresden 2007, DNB  987492365 , urn : nbn: de: swb: 14-1198868584143-77693 (dissertation, Technical University of Dresden).
  • F. Pragst : Meeting of the Society of Hair Testing. (PDF; 46 kB) in T + K 74, 2007, pp. 121–123. (in German language)
  • Hair analysis in environmental medicine. In: Bundesgesundheitsblatt 2005; 48: 246–250.
  • T. Hamilton and F. Schweinsberg: Results of a round robin test with hair samples from a healthy volunteer - a contribution to the critical evaluation of the hair mineral analysis. In: Environmental Medicine in Research and Practice 8, 2003, pp. 123–130.
  • OH Drummer: Postmortem toxicology of drugs of abuse. In: Forensic Science International 142, 2004, pp. 101-113.
  • RE Joseph et al .: In Vitro Characterization of Cocaine Binding Sites in Human Hair. 282, 1997, pp. 1228-1241.
  • M. Gratacos-Cubarsi et al: Hair analysis for veterinary drug monitoring in livestock production. In: Journal of Chromatography B , 834, 2006, pp. 14-25.
  • T. Mieczkowski: Assessing the potential of a `` color effect '' for hair analysis of 11-nor-9-carboxy-D9-tetrahydrocannabinol: Analysis of a large sample of hair specimens. In: Life Sciences 74, 2003, pp. 463-469.

Individual evidence

  1. ↑ a b c d C. Stadlbauer: Can the non-substance nature of potentized drugs be made substantially visible? Heavy metals in human tissues. In: Österreichische Apotheker-Zeitung 2006, 60 (22), 1067.
  2. ^ Edzard Ernst : Complementary medical diagnostic procedures. Dtsch Arztebl 2005; 102 (44): A-3034 / B-2560 / C-2410.
  3. ↑ a b c M. Uhl, F. Scheufler: Analysis of hair samples for criminal proceedings. In: Laborpraxis from December 6, 2006.
  4. ↑ as Madea and F. Mußhoff include: hair analysis German Medical Publishers, 2004, ISBN 978-3-7691-0437-0 .
  5. ↑ a b c d Human biomonitoring: Hair analysis as a method. (PDF; 386 kB) German Research Center for Health and Environment, March 2008.
  6. ↑ L. Rivier: Is there a place for hair analysis in doping controls? In: Forensic Sci Int 107, 2000, pp. 309-323, PMID 10689583 .
  7. ↑ D. Thieme et al: Analytical strategy for detecting doping agents in hair. In: Forensic Sci Int 107, 2000, pp. 335-345, PMID 10689585 .
  8. ↑ Thomas Hasler: With hair analysis against blue drivers. ( Memento from May 5, 2010 in the web archive archive.today ) In: Tages-Anzeiger from May 22, 2007.
  9. ^ AF Holleman , E. Wiberg , N. Wiberg : Textbook of Inorganic Chemistry . 101st edition. Walter de Gruyter, Berlin 1995, ISBN 3-11-012641-9 .
  10. ↑ F. Scherer and S. Schöbel The End of Napoleon - Was the Emperor Poisoned? ( Memento from February 2, 2012 in the Internet Archive ) In: ZDF.de from March 6, 2003.
  11. ↑ G. Bönisch: Brother's hair? In: Der Spiegel . No. 34 , 2001, p. 140 ( online ).
  12. ↑ G. Amendt, Die tageszeitung from October 23, 2000.
  13. ↑ Environmental analyzes by Dr. Guse: Example analysis of a commercial provider (PDF; 94 kB).
  14. ↑ H. Drexler and KH Schaller: Hair analyzes in clinical environmental medicine: A critical consideration. In: Dtsch Arztebl 99, 2002, pp. A-3026 / B-2557 / C-2276.
  15. ^ Agency for Toxic Substances and Disease Registry: Summary Report Hair Analysis Panel Discussion Exploring The State Of The Science. June 2001.
  16. ↑ Stiftung Warentest: pulled by the hair. A test of various hair analysis providers and the terrifying results. In: test 10/2004, pp. 86-90.