Header

UZH-Logo

Maintenance Infos

A possible new oxidation marker for hair adulteration: detection of PTeCA (1H‐pyrrole‐2,3,4,5‐tetracarboxylic acid) in bleached hair


Eisenbeiss, Lisa; Binz, Tina M; Baumgartner, Markus R; Steuer, Andrea E; Kraemer, Thomas (2020). A possible new oxidation marker for hair adulteration: detection of PTeCA (1H‐pyrrole‐2,3,4,5‐tetracarboxylic acid) in bleached hair. Drug Testing and Analysis, 12(2):230-238.

Abstract

Hair analysis has become a valuable tool in forensic toxicology to assess drug or alcohol abstinence. Yet, hair adulteration by cosmetic products presents a major challenge for forensic hair analysis. Oxidative treatments, e.g. bleaching, may lead to analyte loss and thereby to false negative results. Currently, the eumelanin degradation product 1H‐pyrrole‐2,3,5‐tricarboxylic acid (PTCA) serves as a marker for oxidative hair treatment, but requires the definition of cut‐off values. To investigate further eumelanin degradation products as markers for oxidative hair treatment, hair samples with and without in vitro bleaching (hydrogen peroxide (H2O2) concentrations 1.9 % up to 12 %; incubation times 15 min, 30 min, 60 min) were analyzed by liquid chromatography coupled to high‐resolution time of flight mass spectrometry (HPLC‐HRMS). The distribution of eumelanin degradation products along the hair shaft was investigated for routine applicability after segmentation of cosmetically untreated hair samples and authentically treated hair samples. The signals of the eumelanin degradation products PTCA, 1H‐pyrrole‐2,3,4‐tricarboxylic acid (isoPTCA) and 1H‐pyrrole‐2,3,4,5‐tetracarboxylic acid (PTeCA) were found to be significantly elevated after in vitro bleaching already with low H2O2 concentrations and after short incubation times. In contrast to PTCA and isoPTCA, PTeCA was not detectable in cosmetically untreated segments up to 12 cm from hair root and was only formed through the oxidation process. The results of the study show that the detection of PTeCA within the proximal 3 to 6 cm segment can be applied to reliably detect hair adulteration attempts through hair bleaching.

Abstract

Hair analysis has become a valuable tool in forensic toxicology to assess drug or alcohol abstinence. Yet, hair adulteration by cosmetic products presents a major challenge for forensic hair analysis. Oxidative treatments, e.g. bleaching, may lead to analyte loss and thereby to false negative results. Currently, the eumelanin degradation product 1H‐pyrrole‐2,3,5‐tricarboxylic acid (PTCA) serves as a marker for oxidative hair treatment, but requires the definition of cut‐off values. To investigate further eumelanin degradation products as markers for oxidative hair treatment, hair samples with and without in vitro bleaching (hydrogen peroxide (H2O2) concentrations 1.9 % up to 12 %; incubation times 15 min, 30 min, 60 min) were analyzed by liquid chromatography coupled to high‐resolution time of flight mass spectrometry (HPLC‐HRMS). The distribution of eumelanin degradation products along the hair shaft was investigated for routine applicability after segmentation of cosmetically untreated hair samples and authentically treated hair samples. The signals of the eumelanin degradation products PTCA, 1H‐pyrrole‐2,3,4‐tricarboxylic acid (isoPTCA) and 1H‐pyrrole‐2,3,4,5‐tetracarboxylic acid (PTeCA) were found to be significantly elevated after in vitro bleaching already with low H2O2 concentrations and after short incubation times. In contrast to PTCA and isoPTCA, PTeCA was not detectable in cosmetically untreated segments up to 12 cm from hair root and was only formed through the oxidation process. The results of the study show that the detection of PTeCA within the proximal 3 to 6 cm segment can be applied to reliably detect hair adulteration attempts through hair bleaching.

Statistics

Citations

Dimensions.ai Metrics
7 citations in Web of Science®
9 citations in Scopus®
Google Scholar™

Altmetrics

Downloads

30 downloads since deposited on 16 Dec 2019
29 downloads since 12 months
Detailed statistics

Additional indexing

Item Type:Journal Article, refereed, original work
Communities & Collections:04 Faculty of Medicine > Institute of Legal Medicine
Dewey Decimal Classification:340 Law
610 Medicine & health
510 Mathematics
Scopus Subject Areas:Physical Sciences > Analytical Chemistry
Physical Sciences > Environmental Chemistry
Life Sciences > Pharmaceutical Science
Physical Sciences > Spectroscopy
Uncontrolled Keywords:Analytical Chemistry, Spectroscopy, Pharmaceutical Science, Environmental Chemistry
Language:English
Date:1 February 2020
Deposited On:16 Dec 2019 09:52
Last Modified:08 Feb 2021 14:48
Publisher:Wiley-Blackwell Publishing, Inc.
ISSN:1942-7603
Additional Information:For accepted manuscripts: This is the peer reviewed version of the following article: A possible new oxidation marker for hair adulteration: detection of PTeCA (1H‐pyrrole‐2,3,4,5‐tetracarboxylic acid) in bleached hair, which has been published in final form at https://doi.org/10.1002/dta.2713. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived Versions. (http://www.wileyauthors.com/self-archiving)
OA Status:Green
Publisher DOI:https://doi.org/10.1002/dta.2713
PubMed ID:31655024

Download

Green Open Access

Download PDF  'A possible new oxidation marker for hair adulteration: detection of PTeCA (1H‐pyrrole‐2,3,4,5‐tetracarboxylic acid) in bleached hair'.
Preview
Content: Accepted Version
Language: English
Filetype: PDF
Size: 1MB
View at publisher