Value of hair analysis in postmortem toxicology

It is generally accepted that chemical testing of biological fluids is the most objective means of diagnosis of drug use. The presence of a drug analyte in a biological specimen can be used to document exposure. The standard in postmortem drug testing is a general unknown screening, followed by the gas chromatographic/mass spectrometric confirmation conducted on a whole blood sample. In recent years, remarkable advances in sensitive analytical techniques have enabled the analysis of drugs in unconventional biological specimens such as hair. The advantages of this sample over traditional media, like urine and blood, are obvious: collection is almost non-invasive, relatively easy to perform, and in forensic situations it may be achieved under close supervision of law enforcement officers to prevent adulteration or substitution. Moreover, the window of drug detection is dramatically extended to weeks, months or even years. The aim of this review is to document the current status of hair analysis in postmortem toxicology.     

Methadone concentrations in human hair of the head, axillary and pubic hair

The concentrations of methadone and its metabolites in the hair of the head, axillary and pubic hair obtained from patients receiving a daily maintenance doses, were determined. Comparison of the concentrations provides the highest values in the axillary hair, followed by pubic hair and the hair of the head.     

Radioimmunological determination of cocaine in human hair

A simple procedure for the determination of cocaine in human hair was described. After washing hair samples were crushed in 0.1 m HCl and incubated overnight at 45 degrees C. The acid extracts were neutralized with 1 m NaOH. Phosphate buffer (pH 7.4) was added to the extracts. The cocaine concentrations were measured by radioimmunoassay. Detection in hair was achieved in all hair samples obtained from cocaine users. This method appears to be suitable for the routine determination of cocaine.     

Evaluation of cuticula structure of the human hair

The cuticula is influenced by inner and outer factors. Through the combination of these factors the cuticula takes forms, which can be individual in same cases. But in most cases the marks of the cuticula are not enough specific to attach a hair to an individual person. Therefore the hair investigation has to be done in combination with other marks of the hair.     

Shampoo residue profiles in human head hair

Washing hair with shampoo results in an accumulation of shampoo components in the hair. Hair of individuals using different shampoos can be distinguished by analysis of shampoo residues. A method for extraction and analysis of such residues is presented. The hair is extracted using a methanol/water mixture, and the extract is analyzed by reverse-phase high-pressure liquid chromatography (HPLC). The detector system consists of two ultraviolet (UV) detectors connected in series. The method is nondestructive to hair and is sensitive enough to be applied to a single hair 5 to 10 cm in length. Residues from hair balsams are analyzed by this technique as well. The use of this method in forensic science examination of human head hair is demonstrated.     

Determination of methadone in human hair by radioimmunoassay

The concentrations of methadone in human hair were measured. The washed hair was cut in 1-mm pieces approximately, then incubated overnight at 45 degrees C with 0.1 m HCl. The extracts were alcalized by 1 m NaOH and diluted by phosphate buffer, pH 7.4. The methadone concentrations were determined by radioimmunoassay. The method is simple, rapid, and practicable for routine determination.     

Removing and identifying drug contamination in the analysis of human hair

The procedure used in this laboratory for removing and identifying contamination of hair specimens with drugs is demonstrated by its application to hair contaminated by various experimental models. The models include soaking; coating with drug followed by sweat conditions for 6 h; and soaking in a very high concentration of cocaine followed by storage and multiple shampoo treatments. A multi-part wash procedure along with a wash criterion is applied to all samples containing drug above the cutoff. The failure of the wash criterion is a signal that the sample may be positive due to contamination rather than use, and in the absence of other over-riding evidence, the sample would be considered to be negative for drug use. This Wash Criterion has also been tested with hair from subjects demonstrated to be drug users by one or more drug-positive urines; in these studies, all hair samples from demonstrated users passed the Wash Criterion test.     

Examinations of ABO bloodgroupings of human hair

In order to bring into play the function of human hair ABO bloodgrouping in the field of medicolegal expertise on material evidence and raise its accuracy, the author, through a test on human hair of 500, makes some emphatic researches on the disposal of hairs, on the application of anti-A and anti-B serum, on the selection of red blood cell indicator and on the elution temperature as well. Five hundred samples of human hair have been examined upon the basis of the improved operation method and through the application of anti-A and anti-B serum, the titer of which being 1:128, and therein, fine results have been obtained.     

Procedural bias in forensic science examinations of human hair

Several forms of expert forensic science evaluations exist that rely at least in part on the subjective opinion of the examiner. Human hair identification is one such examination. This paper considers possible sources of influence or bias that may be responsible for examiner errors. Data are reported of an experiment that compares the conventional examination procedure (known versus questioned samples) against an alternative procedure (a lineup of samples) designed to limit the influence of factors that contribute to error. The altenative procedure produced fewer incorrect conclusions (3.8%) than the conventional procedure (30.4%).     

Enzyme typing of human hair roots.

Sufficient phosphoglucomutase activity was found to be present in plucked hair noses bearing either fragmentary or complete outer root sheaths to enable typing of individual roots by starch-gel electrophoresis. Hair roots collected by brushing were found to contain very little PGM activity. Other isoenzyme systems were detected in hair roots but in insufficient quantities to make typing feasible.     

Further evaluation of probabilities in human scalp hair comparisons

Placing value on associative hair evidence is an integral part of court presentation. A modified repeat of the hair probability study by Gaudette and Keeping has been undertaken, with steps taken to remedy shortcomings of the original work. The results of this study demonstrate that, with the application of rigid selection criteria, the frequency of coincidental matches in forensic science hair comparisons is low. It also demonstrates that routine hair classification is not feasible, because of inconsistency in examiner discrimination. The macroscopic selection of 5 to 13 mutually dissimilar hairs has been shown to be frequently unrepresentative of the microscopic range of features present in a known hair sample.     

Evaluation of nicotine and cotinine in human hair.

To validate data on tobacco use, the authors investigated the use of hair samples for quantifying nicotine and cotinine by gas chromatography/mass spectrometry. Hair was taken from 22 nonsmokers and 42 smokers, cut close to the scalp at the back of the head. The hair (about 100 mg from each subject) was incubated in 3 mL of 1N NaOH at 100 degrees C for 1 h. After this, the samples were extracted by diethyl ether. The drugs were separated on a 12-m BP-5 capillary column and detected using selected ion monitoring (nicotine, m/z 84; cotinine, m/z 98). Hair from nonsmokers and smokers contains nicotine and cotinine. Although it is difficult to determine an absolute cutoff level, an amount greater than 2 ng of nicotine per milligram of hair can be used to differentiate smokers from nonsmokers. In the population of nonsmokers, the influence of environmental smoke exposure was noted.     

Detection of antidepressant and antipsychotic drugs in human hair

The presence of therapeutic drugs and their metabolites in the hair of psychiatric patients was investigated using gas chromatography (GC)-mass spectroscopy (MS)-electron ionization (EI) and GC-MS-chemical ionization (CI). In hair samples tested from 35 subjects, carbamazepine, amitriptyline, doxepin, trihexyphenidyl, chlorpromazine, chlorprothixene, trifluoperazine, clozapine and haloperidol were detected, with maximal concentrations of 22.5, 57.7, 183.3, 15.6, 68.2, 30.0, 36.8, 59.2 and 20.1 ng/mg of hair sample, respectively. Chlorpromazine and clozapine concentrations in the hair were found to be dependent on the dosage used and their correlation coefficients were 0.8047 (P<0.001, n=16) and 0.7097 (P<0.001, n=16), respectively. Segmental analysis demonstrated that there was a correlation between the history of subject's drug exposure and the distribution of drug along the hair shaft. Our results also show that drug analysis in hair may provide useful information about drug treatment and the history of usage, and that drugs can be detected in normally kept hair for at least 16 months after intake.