Hair analysis for the assessment of alcohol or drug abstinence has become a routine procedure in forensic toxicology. Hair coloration leading to loss of incorporated xenobiotics and to false negative results has turned out to be a major problem. Currently only colored extracts provide hints of manipulations but not bleaching. A liquid chromatographic-tandem mass spectrometric (LC-MS/MS) method was developed and validated to determine 1H-pyrrole-2,3,5-tricarboxylic acid (PTCA), a major oxidation product of melanin. PTCA was determined in natural hair samples (n = 21) after treatment with 3% hydrogen peroxide (H O ) for 30 or 40 minutes with concentrations up to 12% for 40 minutes. In another series, 12 natural hair samples were submitted to different coloration procedures (henna, tinting, semi-permanent and permanent dyeing, bleaching) and the changes in PTCA content were determined. A significant increase in the PTCA content was found for both incubation times and increasing H O concentrations. Coloration with henna or tinting had no influence on PTCA levels detected, but a significant increase was observed after semi-permanent and permanent dyeing and bleaching. As PTCA concentrations in natural hair were found to be in a range of <2.1-16.4 ng/mg (8.4 ± 3.8 ng/mg, mean ± SD, n = 33), a cut-off of 20 ng/mg is recommended for the distinction between natural vs. excessively oxidized hair. In case of naturally low melanin content (light-blond or white hair), no marked increase in PTCA may occur. The present study demonstrated that PTCA is formed during oxidative treatment of melanin in hair, which can be used to detect previous hair coloration including oxidation.

The evaluation of drug and alcohol abuse is a major subject of forensic toxicology. Assessment of drug abstinence currently requires the analysis of urine or hair. In the present study cerumen, a mixture of sebum and sweat, was tested as an alternative. Postmortem samples (blood, urine, hair and cerumen from 38 corpses) were analyzed using liquid chromatography and gas chromatography, each coupled to mass spectrometry (LC-MS, GC-MS). The results were compared. In all cases of recent drug use (i.e. detection of opiates, amphetamine and derivatives, cocaine, methadone and diazepam or their metabolites in blood) the corresponding cerumen was positive. In 3 cases, where drugs could only be detected in urine, cerumen was also found to be positive. Even in cases where only hair was positive cerumen still contained analytes in some instances (52.5%). However, cannabis use was only detected in 31.6% of cerumen samples of the deceased cannabis users. Unexpectedly, not tetrahydrocannabinol (THC) was detected but its oxidized form, cannabinol. The present results suggest that cerumen is a promising alternative for drugs of abuse testing. The detection time window of cerumen is obviously in excess of that of urine but not as long as with hair. However, current problems with the detection of cannabinoids require further research. Copyright © 2017 John Wiley & Sons, Ltd.

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Cerumen was found to be a promising alternative specimen for the detection of drugs. In a pilot study, drugs of abuse were identified at a higher detection rate and a longer detection window in cerumen than in urine. In this study, cerumen from subjects was analyzed after they ingested the designer stimulant 4‐fluoroamphetamine (4‐FA) in a controlled manner. Methods Twelve subjects ingested placebo and 100 mg of 4‐FA. Five of them were also given 150 mg of 4‐FA in 150 mL Royal Club bitter lemon drink at least after 7 days. Cerumen was sampled using cotton swabs at baseline, 1 h after the ingestion of the drug and at the end of the study day (12 h). After extraction with ethyl acetate followed by solid‐phase extraction, the extracts were analyzed using liquid chromatography coupled with tandem mass spectrometry (LC–MS/MS). Results and discussion In the cerumen of all 12 subjects, 4‐FA was detected 12 h after its ingestion; in most subjects, cerumen was detected after 1 h of ingestion, ranging from 0.06 to 13.90 (median 1.52) ng per swab. The detection of 4‐FA in cerumen sampled 7 days or more after the first dose suggested a long detection window of cerumen. Conclusions Cerumen can be successfully used to detect a single drug ingestion even immediately after the ingestion when a sufficient amount of cerumen is used.

Volumen 49, Fasciculus 1 (1966) -No. 91-92 791according to which a silver ion belonging to the lattice is replaced by an interstitial ion and pushed in turn into another interstitial site, and does not proceed by direct jumps from one interstitial site to the next.