I would like to congratulate those participating in this field of research for their contribution regarding hair testing to the scientific community. I find this sort of technology very exciting and it definitely shows promise for the future. However, there is reason to believe that even with these advances, the results obtained are not nearly accurate enough to be used in a commercial setting, especially when the outcome could determine a parent’s future with their children in the court of law. My attention has recently been drawn to a number of companies offering these services such as Trimega Laboratories, which conducts thousands of substance abuse tests each year.
I have recently been reviewing peer reviewed articles regarding hair testing, and more specifically hair testing relating to substances of abuse. The most informative of all seems to be a peer reviewed article accepted in February 2006 titled ‘State of the art in hair analysis for the detection of drug and alcohol abuse’. While reading this article, I came across many discrepancies that led me to believe the results obtained from hair analysis can sometimes be unpredictable or inaccurate. If a company like Trimega Laboratories perform thousands of tests each year (say 3000), and if 1% of results are inaccurate (which is possible as demonstrated below), then Trimega Laboratories would report 30 incorrect results, possibly affecting 30 people or families. There are currently 5000 hair analysis tests for alcohol being carried out each year in the UK, which means that 50 could potentially be inaccurate.
I do also understand that my interpretation of the text in the above mentioned article may be different depending on who the reader is in some instances, and to ensure that my interpretation is in line with the message that this paper is trying to portray, I have copied and pasted extracts from this article (in red italics) with my interpretation and additional comments (in black normal) below.
This study found that the concentration
along the hair shaft differed and corresponded with the time
course of drug intake - INTRODUCTION 1980
in some cases the results correlated and sometimes it did not correlate with time course of drug intake.
Although the anatomy, physiology, physical and
chemical properties of hair have generally been described [28–
33], hair remains an enigmatic structure to date [34,35]
INTRODUCTION
Because of the enigmatic structure from person to person, there is no telling how the wash or other steps could affect the result
The precise mechanisms involved in the incorporation of
drugs into hair remain unclear requiring further investigation.
Incorporation models typically assume that drugs or chemicals
enter hair by passive diffusion from blood capillaries into
growing cells over a length of 1.2 to 1.5 mm between the level
of matrix cells and end of the keratinization zone of the hair
follicle.
INCORPORATION AND ELIMINTATION
Furhter investigation is needed to determine the precise mechanism of incorporation into hair. I would imagine that knowledge of this mechanism is required in order to establish correct time points of substance abuse.
Experimental data, however,
indicates that drugs enter hair by various mechanisms in a
variety of locations, times and sources (Fig. 2). Besides
incorporation from blood, substances can be incorporated,
albeit with some time delay, from deep skin compartments
during hair shaft formation. The most important alternative
mechanism is, however, deposition by diffusion from sweat or
sebum secretions into the completed hair shaft. In addition,
substances can be deposited from the external environment.
INCORPORATION AND ELIMINATION
Because of these various mechanisms of entry involving different locations, times and sources, the time points in the hair strand analysis will be inaccurate. External contamination is very likely.
These include the melanin content of hair
and the lipophilicity and the basicity of the substance itself. For
example, grizzled individuals are particularly suitable to
demonstrate the effect of pigmentation. Gray hair is a mixture
of white and pigmented hair. Despite root exposure to the same
drug concentration in blood, the concentration of basic drugs in
pigmented hair was about 10-fold higher than non-pigmented
hair [42–45]
Regarding cutoff values and establishing when a person is negative or positive: The amount of drug deposited in hair differs with people having different melanin quantities. A 10-fold increase compared to non-pigmented hair is enough error to sway an individuals hair results from a negative to a positive or visa versa. Are these factors calculated in accurately enough?
As such, the pKa of the compound and
pH of the matrix cells are both important
INCORP
Here is another variable. An alcoholics metabolic pH generally decreased/changes while drinking.
The lack of inter-individual correlation between drug
concentration in hair and daily or cumulative dose is not,
however, surprising given the fact that correlation between
dose and blood concentration between individuals is typically
poor.
INCORP
Another variable affecting results of hair analysis is the lack of correlation between dose and blood concentration. This automatically means that there is poor correlation between dose and excretion into hair. How is this factor taken into account? (if A = B and B = C, then A = C)
As can be
seen, mean drug concentration slowly decreases with increasing
distance from the hair root (i.e., increasing age of the hair).
Interestingly, after more than one year in the hair segment (i.e.,
12–15 cm) about 4% of the drugs remain present
INCORP
How is it decided what the rate of decrease of drug concentration over the length of the hair shaft for different individuals are, especially while trying to make an interpretation at the same time of an individual’s substance abuse habits.
Although the cuticle becomes more
susceptible damaged by mechanical stress and increasingly
penetrable for drug elimination, it is affected to a much higher
degree by the cosmetic treatments described above [96–98].
INCORP
Mechanical stress and cosmetic treatments are even more variables. What if one changes to a different hair cream. What if the sample collected have enough mechanical damage. Is it possible to have enough quality control here.
In
fact, decreases of 1–90% of the original drug concentration
can occur. In general, cocaine is less affected than morphine or
6-monoacetylmorphine. The extent of drug decline following
cosmetic treatment is dependent on its initial concentration
and the properties of the hair matrix. Long-term effects of
weather (sunshine, rain, wind) may cause the damage to the
hair shaft with subsequent impacts on drug concentration [99].
The findings indicate that not only the stability of a particular
drug is important but also the influence of UV light and water on
the hair pigment. For example, cannabinoids in hair are
particularly sensitive to sunlight. Of 11 positive THC hair
samples (0.11–1.72 ng/mg), only three remained positive (0.10–
0.35 ng/mg) after 10 weeks in a quartz vessel exposed to daylight
[100].
INCORP
Decreases of 1-90% seems to be too much variability in order to draw a conclusion. This would be like saying that you are positive, but the possibility of error lies between 1-90%. Cosmetics, whether, uv etc are all mentioned as possible contributors that affects the result.
Hair analysis for drugs is preferentially performed in
forensic cases. Because of its serious consequences, the analyst
assumes a high responsibility for obtaining a correct result.
Therefore, the whole process from sampling to result
interpretation must be well organized and precisely performed
to avoid any potential err
PERFORMANCE OF HAIR ANALYSIS
It seems the variability in results can be so unpredictable, that an analyst can only do so much.
Second, drugs could adhere from the environment
of the individual thus potentially contributing to incorrect test
results. This type of environmental contamination is not
unlikely for individuals involved with illegal drugs
DECONTAMINATION
External contamination is an added variable. It is mentioned that analyzing the washing steps can avoid wrong interpretation, but there is no explanation as to how this can be, especially when taking into account the high possibility of external contamination. This would be a crucial step, and quality control is of very high importance.
There is no general consensus with
respect to the hair washing procedure. For example, one
washing sequence for post-mortem hair samples is composed of
0.1% sodium dodecylsulfate in water, distilled water and
acetone. Other procedures include one or two washes with
dichloromethane [103], sequences of different organic solvents
[104] or a brief wash with methanol [105]. Non-protic solvents
such as dichloromethane or acetone are advantageous because
they do not swell the hair thereby extracting materials from the
hair. In contrast, protic solvents such as phosphate buffer or
methanol promote extraction in the washing step by swelling
the hair. Sophisticated multiple step wash procedures coupled
with wash analysis have been described to distinguish between
external contamination from systemic incorporation [106,107].
This validity of these approaches, however, has been questioned
[108,109]. It has been shown in a systematic study that the
analytical outcome of hair analysis can be strongly affected by
the wash procedure used [110]
DECONTAMINATION
In addition to the wash method used, there are also other variables such as time of incubation during washing. Even though a protocol says 5min, the analyst may take 6min for one sample and 4min for another. Also, degree of vortexing (rpm; shaking) or mixing during washing may also play a role in the end result, together with temperature if incubation.
After hair analysis, answers to the following questions are
usually expected:
Did the individual use drugs?
Which drugs were used?
Was it single, occasional, regular or excessive use?
When were the drugs used?
These answers, however, are not typically derived on the sole
basis of analytical results. In general, these issues require expert
and critical examination of the case history, variability of hair
growth (cf. Section 2) and the hair sample itself, drug
pharmacology and thorough review of findings in other cases
previously investigated or described in literature.
INTERPRETATION SECT 4
This paragraph indicates that the final result could in fact depend on the interpretation of the analyst and is not clear cut. Results may therefore differ between analysts. It seems that the first two questions can be answered using this method, but the degree of variability makes answering the other two questions unreliable.
In fact,
deposition of cocaine in hair has been experimentally shown for
both the solid hydrochloride form as well as the evaporated base
[108,182,189,190]. In one study, cocaine hydrochloride powder
(10 mg) was uniformly applied to the scalp of four volunteers
[108]. Cocaine was detectable (1.8 ng/mg) ten weeks post
exposure. Interestingly, benzoylecgonine (cocaine metabolite
and hydrolysis product) increased during this time period from
0.0 to 0.8 ng/mg. In another study, the hair of toddlers who lived
in a household where crack was smoked was also examined
[191]. This study found toddler hair cocaine concentrations
nearly as high as the smokers themselves [191]. Controlled
experiments with environmental marijuana smoke exposure
demonstrated that false-positive or falsely increased drug test
results could be obtained in hair
SECT 4.1 DRUG CONSUMPTION OR EXTERNAL CONTAMINATION
This whole paragraph indicates that external contamination can persist even 10 weeks (more than 2 months) after exposure of the drug to the hair.
Based on the above studies, environmental hair contamination
is likely complication given by the appropriate circumstances.
In lieu of passive exposure, hair can be intentionally
treated with powdered or dissolved drugs to portray addiction as
a mitigating circumstance following arrest.
SECT 4.1
And these things do happen!
As described earlier, there is no inter-individual
correlation between frequency of drug use or drug dose with
hair concentration
SECT 4.2.1 - INTERPRETATION OF HAIR CONCENTRATIONS
This means that if the drug metabolites decrease over time, it does not necessarily mean that the individual is using less drugs, and vise versa, because of a lack of correlation.
Possible reasons for exceptionally low drug
concentrations such as very fair or cosmetically treated hair
should be taken into account.
SECT 4.2.1
To which extent? When, how, which race, which age etc. There is no explanation.
Until present,
no relevant statistical analyses have been performed for
determination of appropriate drug cut-off concentrations in
hair. Because of these limitations, a revision of these drug cut
off values is expected when better substantiated data are
available.
SECT 4.2.2 CUT OFF VALUES
Can the current cut-off values be accepted? Should it not be lower, or higher? Who decides this? Should these cut-off values not change depending on the person in question?
Under ideal conditions, the position of drug molecules in a
hair sample can be used to calculate the date of intake by Eq.
from growth rate, date of sampling and length of the residual
Stubble
What constitutes ideal conditions? Are there ever ideal conditions considering the amount of variables to be considered?
ti ¼ ts−1i=vh−1r=vh−t0 ð1Þ
ti time of the drug intake
ts time of the hair sampling
t0 time between incorporation of the drug into the hair
root and appearance at the skin surface
li distance of the drug position in hair from the proximal
end of the hair sample
lr length of the residual hair shaft from the skin surface
after sampling
vh hair growth rate.
Prerequisites are a uniform, constant and known hair
growth rate, and that the incorporation of the drug occurs
only in the hair root. The resulting theoretical drug distribution
along the length of a hair tuft is compared versus time scale
(Fig. 10a and b) for a one month-long drug intake. Time
resolution would be about three days corresponding to a
distance of 1.2–1.5 mm between matrix cells and end of the
keratinization zone (Fig. 1a) and can be increased for drugs
with longer half-life in blood.
Many examples that demonstrate this agreement between the
drug history and drug concentrations in hair segments have been
published [176,216–219]. Conversely, there are also many
experimental results that emphasize the limits caused by
heterogeneous physiology of hair growth and alternative drug
incorporation mechanisms as described earlier [82,92,164,220].
Alterations of the drug distribution along the hair sample
may result from a variety of causes (Fig. 10c–g). Slowly
growing strands (Fig. 10c), catagen and telogen hair (Fig.
10d), and delayed incorporation from tissues (Fig. 10e) cause
an extension of the drug zone in proximal direction, whereas
fast growing strands (Fig. 10c) and incorporation from sweat
(Fig. 10f) or sebum (Fig. 10g) lead to an extension of the drug
zone in the distal direction. The degree to which these effects
influence hair drug distribution depends on the individual
(large portion of telogen hair), the pharmacokinetics of the
drug (high excretion rate in sweat or sebum) and on the
occasion of drug use (extreme sweating during a rave party)
and varies from nearly the ideal curve (clearly defined region)
to a distribution over the whole hair length. However, there is
no axial migration of the incorporated drug within the hair
strands and there are no indications for drug transport (i.e.,
distal to proximal) [221]. Therefore, proximal hair must be
drug-free after several months of abstinence.
As a rule, a complete drug history of a person is
generally not required with more attention focused on the
details of the circumstances surrounding the case history.
This focus must already be taken into account at the
beginning of the analysis for a proper choice of the
segmentation. Some examples shall be discussed below. In
generally, it is common to assume a hair growth rate of 1
cm/month, although a growth rate of 1.1± 0.2 cm/month
would be more accurate
Regarding time analysis. Another variable is that the growth rate of an individuals hair may not always be uniform. If a person changes their diet, the growth rate of hair may change. Such as a person consuming foods rich in methylsulfonylmethane(???). There is also mention about alterations caused by many sources. This equation can only be used under highly controlled clinical studies because it is almost impossible to collect all the variables when a hair sample is collected.
SECT 4.3 - INTERPRETATION CONCERNING TIME
Because of these limitation
and the effects shown earlier (Fig. 10), only a time period range
can be estimated.
SECT 4.3.2 TIME PERIOD PRESENTED
Delayed incorporation from depots in surrounding tissues
may lead to an increased time period following shaving. This
phenomenon appears particularly true for lipophilic THC stored
in fat tissues (Fig. 11) [223]. A 26 year-old male with habitual
marijuana use was summoned to hair analysis because of doubts
regarding his driving ability. He shaved his head and stopped
drug use. Analysis of a 2.5 cm long hair sample (about 3 months
later) revealed the presence of THC (1.7 ng/mg). Despite
shaving his hair again, analysis of a 1.5 cm long hair sample
(about 1.5 months later) contained THC (0.25 ng/mg). Despite 4
months abstinence, THC can be incorporated into newly grown
hair at concentrations consistent with occasional drug
consumption.
SECT 4.3.2
The sort of incorporation described above renders interpretations for THC very inaccurate. This sort of phenomenon appears to not have been researched previously.
Although hair analysis cannot conclusively prove
retrospective drug use to a specific date, it can provide
approximate dates of alleged drug use. Under these circumstances,
the approximate position on the sample length
corresponding to the date of the crime should be calculated
by Eq. (1)
SECT 4.3.3 TESTING FOR PREVIOUS DRUG USE
Again, Eq.(1) becomes difficult to use because of the many variables. How can one determine the growth rate of an individuals hair and in turn decide where the variability in growth rate occurred.
Therefore, time-resolved interpretations with
respect to previous drinking and abstinence are not possible
SECT 5.7.1 FATTY ACID ETHYL ESTERS
“are not possible” is the key phrase!
Although hair shampooing, permanent wave,
dyeing, bleaching or shading did not affect results, frequent use
of hair lotions containing ethanol was found to increase the false
positivity rate.
SECT 5.7.1
A lawyer can claim that a client was using a hair lotion containing ethanol at different frequencies, and that the results are therefore invalid or inconclusive, and therefore inadmissible.
It should be
noted, however, that a negative hair EtG result does not
completely exclude abuse because no EtG was detected in some
hair samples obtained from alcoholics.
SECT 5.7.2 ETG
How is this variable calculated in the equation?
Although increased
analytical sensitivity has generally decreased the number of
false negative results, positive EtG results have also been found
in hair from social drinkers (private communication from M.
Yegles, Luxembourg)
SECT 5.7.2
This is the opposite of the previous extract. How is this calculated in?
A temporal relationship has not been
demonstrated for segmental hair EtG concentration and time
course of self-reported alcohol consumption [93].
SECT 5.7.2
If a positive control did not even work correctly, how can the analysis be remotely correct also while taking into consideration the other variables.
Improved analytical technology has resulted in
improved sensitivity and accuracy thus providing better
scientific understanding and test interpretation.
SECT 6
There is no dispute that the analytical technology (GC/MS) is correct. It is the incorporation of drugs into hair that becomes questionable.
Despite these advances, assay performance will continue to
be challenged by biologic variables including differences in hair
growth and mechanisms of drug incorporation. As can be
expected, the complex nature of the issues addressed in this
review will require continued research in this field and
appropriately trained and experienced scientists now as well
as in the future.
SECT 6
This paragraph sums everything up very well. “challenged by biological variables including differences in hair growth rate and mechanisms of drug incorporation”. Are you referring to all of the variables in the above texts?
ALSO
PATENT
Regarding the patent WO 2008/122805, where the inventors claim a method for the analysis of ETG and FAEE in hair. The methods described sound very similar to what is/was already in the open domain. This means that this patent should not be valid. If it is valid, then nobody else can use ETG and FAEE analysis in hair, except by permission from the applicants.
In addition, other papers also to make mention of!
Estimation of the measurement uncertainty of methamphetamine and amphetamine in hair analysis.
National Institute of Scientific Investigation, 331-1 Sinwol-7-dong, Yangcheon-gu, Seoul 158-707 Republic of Korea. spp26625@yahoo.co.kr
The measurement uncertainties (MUs) were estimated for the determination of methamphetamine (MA) and its main metabolite, amphetamine (AP) at the low concentrations (around the cut-off value of MA) in human hair according to the recommendations of the EURACHEM/CITAC Guide and "Guide to the expression of uncertainty in measurement (GUM)". MA and AP were extracted by agitating hair with 1% HCl in methanol, followed by derivatization and quantification using GC-MS. The major components contributing to their uncertainties were the amount of MA or AP in the test sample, the weight of the test sample and the method precision, based on the equation to calculate the mesurand from intermediate values. Consequently, the concentrations of MA and AP in the hair sample with their expanded uncertainties were 0.66+/-0.05 and 1.01+/-0.06 ng/mg, respectively, which were acceptable to support the successful application of the analytical method. The method precision and the weight of the hair sample gave the largest contribution to the overall combined uncertainties of MA and AP, for each.
PMID: 19179027 [PubMed - indexed for MEDLINE]
Forensic Sci Int. 2004 Oct 29;145(2-3):143-7.
Cannabinoids in hair: strategy to prove marijuana/hashish consumption.
Bayerisches Landeskriminalamt, Maillingerstrasse 15, 80636 Munich, Germany.
Delta9-Tetrahydrocannabinol (THC) and 11-nor-Delta9-tetrahydrocannabinol-9-carboxylic acid (THCA) are equally used to indicate consumption of cannabis (hashish and marijuana). Publications of the early 90's demonstrate the possibilities of determining THC, cannabinol (CBN), and cannabidiol (CBD). All these substances are present in cannabis smoke and can be incorporated into the hair only by contamination. Generally, washing procedures should prevent false positive results, but finally it cannot be excluded that traces of THC may be found in hair after mere passive cannabis smoke exposure. Three authentic cases illustrate the problems originating in the exclusive determination of THC/CBN. The first example is the case of a couple living together in an apartment. Both persons' hair samples had been taken and gave positive results for THC and CBN. The male subject admitted smoking cannabis several times per day, but the female mate denied any consumption. Examination of the hair for THCA showed a high level (>6.6 pg/mg) in the sample of the male person and negative results (LOQ 0.1 pg/mg) in the sample of his mate. The second case hair is of a self admitted cannabis user's hair and was tested first by an immunoassay and GC/MS with a negative result. Nevertheless, the THCA concentration quantified in his sample was 2.7 pg/mg hair. The third hair sample is of a 2-year-old child that was tested positive for cannabis by using an immunochemical test. No THC and CBN were detectable by GC/MS, however, trace amounts of THCA using GC/MS/MS. A comparative study of hair samples (screening for cannabinoids using ELISA test, THC determination by GC/MS, THCA by GC/MS/MS) showed that only 26 segments of 66 were positive for both THC and THCA. Thirteen were negative for THC and positive for THCA, and six were positive for THC but negative for THCA. The cases were selected by an ELISA test or re-examined when the blood/urine results or the statement of the accused did not match with a THC outcome. The most appropriate strategy to prove cannabis consumption is immunochemical initial test followed by a GC/MS/MS confirmation of THCA.
PMID: 15451086 [PubMed - indexed for MEDLINE]
Originally published in (eds. Edward. J. Cone, Ph.D., Michael. J. Welch, Ph.D., and M. Beth Grigson Babecki, M.A.) Hair Testing for Drugs of Abuse: International Research on Standards and Technology, 1995, p. 91-120. NIH Publication No. 95-3727.
ANALYSIS OF HAIR FOR COCAINE
Gary L. Henderson, Martha R. Harkey, and Reese T. Jones
The use of hair as a specimen to detect cocaine use was first reported in 1981 (Arnold and Püschel 1981; Valente et al. 1981). In those studies, hair samples from suspected drug abusers were analyzed by radioimmunoassay (RIA) for the cocaine metabolite benzoylecgonine (BZE) in an attempt to verify a history of cocaine use. Additional studies using RIA followed shortly thereafter (Arnold and Püschel 1981; Valente et al. 1981; Baumgartner et 1982; Smith and Liu 1986; Michalodimitrakis 1987). The first gas chromatography/mass spectrometry (GC/MS) procedures for detecting cocaine in hair were not reported until 1987 (Balabanova and Homoki 1987). When this more specific technique was used, it was found that cocaine, not BZE, is the primary analyte in hair. The metabolites BZE and ecgonine methyl ester (EME), shown in figure 1, are present in such low and variable concentrations that they may result from environmental degradation of cocaine already present in hair. Because of the lack of specificity used in some of the early studies, it is difficult to evaluate much of this literature. For example, some investigators quantitated "cocaine" in hair using RIA antibodies highly specific for BZE, whereas others used RlAs more specific for cocaine. In addition, some digestion or extraction procedures could have caused degradation of cocaine.
Pasted from <http://www.druglibrary.org/schaffer/cocaine/cokehair.htm>
Proficiency test for the analysis of hair for drugs of abuse, organized by the Society of Hair Testing.
Instituto Nacional de Toxicología, P.O. Box 863, 41080 Seville, Spain. cjurado@arrakis.es
Eighteen laboratories interested in the analysis of human hair for drugs of abuse participated in a proficiency test (PT) organized by the Society of Hair Testing (SoHT) in 2001. Samples sent to the participants included one drug-free hair sample and two samples from drug users, sent in the form of short segments previously checked for homogeneity by three reference laboratories. Participants were requested to analyze the samples following the standard procedure used routinely in their laboratories.The compounds present in the samples included opiates, cocaine and metabolite, cannabinoids and amphetamines. All the laboratories analyzed opiates, cocaine and benzoylecgonine (BE); only 10 analyzed amphetamines, and 9 cannabinoids. Various methods were used to extract drugs from the hair-enzyme treatment, acidic, basic and methanol extractions. All the laboratories employed GC-MS, with the exception of two which used GC-MS/MS and LC-MS/MS, respectively. Six laboratories performed initial screening tests by RIA, ELISA or EMIT. Results show that the laboratories performed well qualitatively, since they successfully identified all the analytes that they tested, with the exception of eight false results. However, the scatter of quantitative results was high.
Copyright © 2002 Elsevier Science Ireland Ltd. All rights reserved.
Determination of drugs of abuse in hair: evaluation of external heroin contamination and risk of false positives
Guido Romano
,
, Nunziata Barbera, Giorgio Spadaro and Vincenzo Valenti
Dipartimento di Anatomia, Patologia Diagnostica, Medicina Legale, Igiene e Sanità Pubblica, Università di Catania, Via S. Sofia 87—Comparto 10, 95123, Catania, Italy
Received 31 August 2002;
accepted 18 October 2002. ;
Available online 27 November 2002.
Abstract
One of the most controversial point regarding the validity of hair testing is the risk of false positive due to external contamination. The aim of our experience is to verify if a 5 consecutive days contamination with a small amount of a powdered mixture of heroin hydrochloride and acetylcodeine hydrochloride (10:1 w/w) will last sufficiently long to make a contaminated subject indistinguishable from active users, and if normal washing practices together with the decontamination procedure are sufficient to completely remove the external contamination.
Our results suggest that decontamination procedures are not sufficient to remove drugs penetrated into hair from external source. In fact, all contaminated subjects were positive for opiates (heroin, 6-MAM, morphine, acetylcodeine and codeine) for at least 3 months.
Significant 6-MAM concentrations (>0.5 ng/mg) were found in each subject until 6th week. Further, 6-MAM/morphine ratio were always above 1.3.
Copyright © 1995 Published by Elsevier Ireland Ltd.
Drug testing by urine and hair analysis: complementary features and scientific issues
Robert L. DuPonta and Werner A. Baumgartner
a Institute for Behavior and Health, Inc., 6191 Executive Boulevard, Rockville, MD 20852, USA
b Psychemedics Corporation, 5832 Uplander Way, Culver City, CA 90230, USA
c Radioimmunoassay Laboratory, Nuclear Medicine Service, West Los Angeles Veterans Administration Medical Center;, Los Angeles, CA 90073, USA
Received 10 May 1994;
accepted 29 June 1994.
Available online 7 April 2000.
Abstract
Hair analysis and urinalysis are complementary tests for establishing drug use. Hair analysis provides long-term information, from months to years, concerning both the severity and pattern of drug use. In contrast to this, urinalysis can indicate only drug use, and then generally only that which has occurred within the last 2–3 days. Field studies have demonstrated that hair analysis is considerably more effective than urinalysis at identifying drug users. This difference is due to the wider surveillance window of hair analysis and to the susceptibility of urinalysis to evasive maneuvers. The main concerns with urinalysis are endogenous evidentiary false positives caused by passive drug exposure, e.g., ingestion of poppy seed. This problem arises from the hypersensitivity of the urine test, i.e. the need to use low cut-off levels in order to compensate for the temporary recording of drug use. This problem does not occur with hair analysis since its wide window of detection and permanent record of drug use ensure that the detection efficiency of the test is not compromised by the use of more effective cut-off levels guarding against passive endogenous drug exposure. On the other hand, exogenous evidentiary false positives due to external contamination of hair by drugs present in the environment (e.g., smoke) are the main concern of hair analysis. This problem, however, can be effectively avoided by washing the hair specimen, by kinetic analyses of the wash data, and by measurement of metabolites. The possibility of bias due to race and/or hair color is avoided by the exclusion of melanin from the analysis of hair. The safety and effectiveness of hair testing has been established by extensive field studies with over 400 000 specimens.
Copyright © 2007 Elsevier Ireland Ltd All rights reserved.
Influence of bleaching on the enantiomeric disposition of amphetamine-type stimulants in hair
Liliane Ferreira Martinsa,
,
aNational Laboratory of Health, Toxicology Division, University of Luxembourg, 162A avenue de la Faïencerie, L-1511, Luxembourg
bFTC, Munich, Germany
Received 24 May 2007;
accepted 19 June 2007.
Available online 14 November 2007.
Abstract
The aim of this work was to study the influence of hair bleaching on the enantiomeric ratios of amphetamine-type stimulants (ATS), including amphetamine, methamphetamine, 3,4-methylenedioxyamphetamine, 3,4-methylenedioxymethamphetamine and 3,4-methylenedioxyethylamphetamine. Hair specimens from 14 STA users were treated with a commercial bleaching product during 40 min. After alkaline digestion and solid-phase extraction of bleached and non-bleached hair, the STA enantiomers were derivatised with an in-house synthesised chiral reagent, the (2S,4R)-N-heptafluorobutyryl-4-heptafluorobutoyloxy-prolyl chloride. The diastereoisomers were quantified by GC/MS-NCI.
The results showed that the concentrations of all enantiomers decreased in bleached hair in comparison with the non-treated hair (median values between 20 and 39%). The enantiomeric ratios of the STA in bleached hair were not significantly different from those determined in non-treated hair. Our findings pointed out that bleaching treatments decrease concentrations of STA in hair without influencing their enantiomeric ratios.
Keywords: Amphetamine-type stimulants; Enantiomeric ratios; Bleaching treatments; Hair analysis
These are my concerns.
Kind Regards
