Influence of bleaching and coloring on ethyl glucuronide content in human hair

Abstract

Ethyl glucuronide (EtG) is increasingly used in forensic toxicology as a marker for alcohol use in analyses of hair samples, especially in abstinence control. Some cosmetic treatments are considered to markedly reduce the EtG content. In view of especially many women with coloured hair the present study was performed to further investigate the effect of a variety of colouring procedures (bleaching, tinting, permanent and semi-permanent dyeing, henna) on the EtG content.Untreated hair samples (n = 12, EtG 13.9-64.7 pg/mg) were re-analyzed (gas chromatography-negative chemical ionization mass spectrometry, 0.8 pg/mg quantification limit) after different treatment procedures. A decrease of the EtG content of at least 10% occurred in every case. The reduction in comparison to the untreated hair was expectedly high for permanent dyeing and bleaching with 18.1% of the initial content (median, range 0.0-50.9%) and 18.4% (0.0-46.7%), respectively. For henna this was 38.3% (0.0-83.0%), for tinting 70.4% (29.0-90.8%), for semi-permanent dyeing 41.9% (0.0-77.4%). With permanent hair dye the EtG content was decreased to below 7 pg/mg in 10 of 12 cases, in 3 cases even below the LOD (0.2 pg/mg). Surprisingly henna treatment without oxidative component had a marked influence, EtG was below 2 pg/mg in 2 of 12 samples. The study showed that all tested coloration procedures markedly affected the deposited EtG content. Even temporary or henna coloration may have a marked effect. The present data support the recommendation to exclude hair samples with colour manipulations for analysis on the EtG content as a precaution in alcohol abstinence programs.

PTCA (1H‐pyrrole‐2,3,5‐tricarboxylic acid) as a marker for oxidative hair treatment

“…Correlation of the EtG decrease (data in Petzel‐Witt et al) with the PTCA increase using the Spearman's rank correlation test was not significant (Spearman's rho = 0.248, p = 0.056). After excluding data of hair samples treated with henna and tinting, which exhibited PTCA contents that were not different from those of untreated hair, the correlation was also not significant (Spearman's rho = 0.238, p = 0.162).…”

“…The 12 natural hair samples used in a previous study exhibited PTCA contents of 7.6 ± 4.7 ng/mg (mean ± SD, range < 2.1–16.4 ng/mg). After cosmetic treatment with hair coloring products, the PTCA content (Table ) significantly increased for semi‐permanent dyeing (13.6 ± 8.2 ng/mg, p = 0.045), permanent dyeing (26.5 ± 13.8 ng/mg, p < 0.01) and for bleaching (41.1 ± 17.1 ng/mg, p < 0.001).…”

“…From a previous study natural hair samples from 12 different donors were available that were also treated with 5 different coloration procedures for 40 minutes and EtG concentrations had been determined. In the present study, these samples were analyzed for their PTCA content to evaluate a potential correlation of EtG decrease with increasing PTCA‐levels.…”

“…However, a major drawback is that cosmetic treatment affects the detectability of deposited xenobiotics which is eventually used for adulteration of analyses . In particular, oxidative hair treatments, such as permanent coloring or bleaching, have been shown to be detrimental, for example for the detection of the ethanol metabolite ethyl glucuronide . In cases where such treatment is not disclosed, negative analysis results may be wrongly evaluated as an indication of abstinence.…”

Systematic optimisation of ethyl glucuronide extraction conditions from scalp hair by design of experiments and its potential effect on cut‐off values appraisal

“…2 The applications of EtG determination in hair range from compliance to driving regulation 3 to workplace testing 4,5 and many other usages of clinical and forensic interest. However, several studies have shown that bias can be induced by cosmetic treatments 13 exposure to chlorinated water, 14 external contamination by EtG-containing lotions, 15 and many others. [7][8][9] In practice, the effectiveness of EtG determination in hair as a biomarker for chronic excessive alcohol consumption outperforms all the other alcohol biomarkers [10][11][12] to the extent that is frequently used as a unique laboratory testing.…”