Evidence of seasonal variation of ethyl glucuronide in hair: Modeling a seven-year data series

Accelerated Extraction and Analysis of Ethyl Glucuronide in Hair by Means of Pressurized Liquid Extraction Followed by Liquid Chromatography-Tandem Mass Spectrometry Determination

The measurement of ethyl glucuronide (EtG) in hair is an established practice to evaluate alcohol consumption habits of the donors; nevertheless, analytical variability has shown to be an important factor to be considered: measured EtG values can vary significantly as a consequence of analyte washout during decontamination, pulverization of samples, extraction solvent and incubation temperature. In the present study, we described a new method for automated hair decontamination and EtG extraction from the inner core of the hair by using pressurized liquid extraction (PLE), followed by solid-phase extraction (SPE) cleanup; validation was performed according to SWGTOX guidelines. The extraction efficiency of the new method was evaluated by comparing the results with those obtained by a validated and ISO/IEC 17025:2005 accredited method; an average positive difference of + 32% was observed when the extraction was performed by PLE. The effect of hair pulverization was also studied, and a good correlation between cut and milled hair was observed, implying that PLE allowed a highly efficient extraction of EtG from the inner keratin core of the hair, no matter if it has been cut or pulverized. Finally, to verify the results, paired aliquots of 27 real hair samples were analyzed with both PLE and a protocol optimized by design-of-experiment strategies planned to maximize the extraction yield; in this case, a comparable efficiency was observed, suggesting that exhaustive EtG extraction was obtained with both approaches. This finding opens new perspectives in the eligible protocols devoted to hair EtG analysis, in terms of speed, automation and reproducibility.

Does Eumelanin Oxidation Play a Role on the Photostability of Ethyl Glucuronide in Hair Exposed to Simulated Solar Radiation?

The action of solar radiation on the concentration of the ethanol metabolite ethyl glucuronide (EtG) in 40 hair samples of nonabstinent subjects was investigated. Hair samples of different colors were analyzed before and after irradiation with artificial sunlight under a light dose corresponding to 3 months of sun exposure. After irradiation, an increase of EtG concentration was detected in 55% of the samples ranging from 5% to 141%. In 16 cases, a concentration reduction ranging from -2% to -74% was observed. The measure of the level of pyrrole-2,3,5-tricarboxylic acid (PTCA), a marker of eumelanin oxidation, demonstrated the largest increase in oxidation in light brown hair where the greatest degradation of EtG was observed after irradiation. However, the rise of PTCA in all hair tested was accompanied by increase in EtG concentration in 8/10 samples and by decrease in 2/10, suggesting no correlation between the two markers. To verify if hair structure was modified by light, scanning electron microscopy (SEM) analysis was performed on irradiated hair of different colors and compared with the dark samples. SEM revealed modification of hair structure in all samples showing partial shaft exfoliation and reduction of hair thickness under the treatment with solar radiation.

The Impact of COVID-19 Pandemic and Lockdown on Alcohol Consumption: A Perspective From Hair Analysis

Introduction and Aims: The increase in stress levels, social confinement, and addiction's physical consequences play an essential role in the proliferation of drug abuse. In this context, the Covid-19 pandemic produced remarkable effects on those individuals prone to addictions, especially to alcohol. Alcohol is linked to multiple dangerous conditions such as social issues, severe medical conditions, and road accidents. The determination of ethylglucuronide (EtG) in hair is frequently performed to test and monitor chronic excessive alcohol intake conditions, as it allows differentiation among low-risk/moderate drinkers, and excessive/chronic drinkers. Our study aimed to explore hair EtG levels in a controlled population to assess the impact of Covid-19 lockdown on alcohol intake along March-May 2020. Materials and Methods: EtG levels were measured in all hair samples collected in the months following April 2020 to evaluate the behaviors related to alcohol intake along with the time frame from March to May 2020. The measured concentration distributions for each month were compared with those reported in the same month during the previous 4 years (2016-2019). The dataset was built to highlight possible differences between genders, and the different categories of alcohol consumption, separately. Results: The samples collected from April to August 2020 (500 < N <1,100 per month) showed an increase in the percentage of subjects classified as abstinent/low-risk drinkers (from 60 up to 79%) and a decrease of subjects classified as moderate and chronic drinkers (-12 and -7%, respectively) when compared to the previous 4 years. A decrease in the overall mean value of EtG in the period April-June 2020 was observed, while the EtG levels of both June and July 2020 provided an increasing trend for chronic/excessive consumers (+27 and +19% for June and July 2020, respectively). A peculiar rise in the EtG levels of moderate and chronic/excessive female consumers was observed along April-June 2020, too. Discussion and Conclusions: Behavioral and social studies generally report a decrease in alcohol consumption during the Covid-19 lockdown. However, people already suffering from drug or alcohol addictions before Covid-19 pandemic seemingly enhance their harmful behavior. Our data from April to August 2020 are consistent with both suppositions. Our observations confirm once again the utility of EtG to investigate the patterns of alcohol consumption in the population.