Identification and analysis of damaged or porous hair

Abstract

Cosmetic hair treatments have been referred to as 'the pitfall' of hair analysis. However, most cosmetic treatments, when applied to the hair as instructed by the product vendors, do not interfere with analysis, provided such treatments can be identified by the laboratory and the samples analyzed and reported appropriately for the condition of the hair. This paper provides methods for identifying damaged or porous hair samples using digestion rates of hair in dithiothreitol with and without proteinase K, as well as a protein measurement method applied to dithiothreitol-digested samples. Extremely damaged samples may be unsuitable for analysis. Aggressive and extended aqueous washing of hair samples is a proven method for removing or identifying externally derived drug contamination of hair. In addition to this wash procedure, we have developed an alternative wash procedure using 90% ethanol for washing damaged or porous hair. The procedure, like the aqueous wash procedure, requires analysis of the last of five washes to evaluate the effectiveness of the washing procedure. This evaluation, termed the Wash Criterion, is derived from studies of the kinetics of washing of hair samples that have been experimentally contaminated and of hair from drug users. To study decontamination methods, in vitro contaminated drug-negative hair samples were washed by both the aqueous buffer method and a 90% ethanol method. Analysis of cocaine and methamphetamine was by liquid chromatography-tandem mass spectrometry (LC/MS/MS). Porous hair samples from drug users, when washed in 90% ethanol, pass the wash criterion although they may fail the aqueous wash criterion. Those samples that fail both the ethanolic and aqueous wash criterion are not reported as positive for ingestion. Similar ratios of the metabolite amphetamine relative to methamphetamine in the last wash and the hair is an additional criterion for assessing contamination vs. ingestion of methamphetamine.

Amitriptyline poisoning of a baby: How informative can hair analysis be?

“…This profile was consistent with a massive AMI exposure. The hair contamination by sweat was commonly described for AMI, excessive sweat production being an adverse effect of AMI, and high concentrations in distal segments could be explained by a greater porosity [20,21]. Baby hair contamination by sweat has also been suggested for carbamazepine [22].…”

Detection of Benzodiazepines and z-Drugs in Hair Using an UHPLC-MS/MS Validated Method

“…Samples from Psychemedics were decontaminated following their own published protocol before being sent to the laboratory for the confirmation Ultra High Performance Liquid Chromatography-Tandem Mass Spectrometry analysis. 17 The hair samples were then transferred to individual disposable tubes containing six 2.8-mm stainless steel beads and pulverized into a fine powder (3 · 60 s at 6500 rpm) using a ball mill Precellys 24 (Bertin Technologies).…”

New Challenges and Perspectives in Hair Analysis

“…While physical agents do not appear to produce substantial modification of the hair cuticle [12], considerable alteration of hair porosity [13] is induced by the chemical products utilized in several cosmetic treatments, including perms, bleaching, and dyeing [14À16]. Under these circumstances, it is virtually impossible to distinguish the release of the incorporated substances through the pores and cavities produced at the hair surface [12,15], from their possible loss by chemical reaction with cosmetic products.…”

“…Recent studies carried out to investigate the effects of cosmetic treatments on hair content stability have chiefly concerned amphetamines [13,19,20] and cocaine [12,13,21]. In general, the variability of hair features in humans (thickness, color, curly/straight), together with the vast assortment of cosmetic products, have prevented any systematic study of their effects, but rather spot conditions have been tested.…”

“…A well-structured strategy has been recently devised [13] to measure the degree of hair porosity, to deduce the differences occurring between "normal" cosmetic treatments from "extreme" treatments-possibly carried out by drug users to circumvent positive hair testing-to distinguish external contamination from actual intake for both normal and damaged hair, and to establish a correct washing/decontamination protocol for each of these cases. As previously cited [17], mild cosmetic treatments applied according to the vendor instructions appear to be compatible with hair testing for drug and alcohol abuse [13].…”