Micro-segmental hair analysis: detailed procedures and applications in forensic toxicology

Effects of natural environments on drug contents in nails: comparison of drug residual rates between nails and hair to determine the drug-use history of corpses in unnatural death cases using micro-segmental analysis

PURPOSE

We previously developed evaluation methods using micro-segmental analysis (MSA) to examine the effects of external environments on drug content in hair and nails. In this study, the effects of the natural environmental factors (water, temperature, humidity, light, and soil) on drug contents in nails were examined and compared with our previous experimental data on hair.

METHODS

Four hay-fever medicines were used as model drugs (fexofenadine, epinastine, cetirizine, and desloratadine) to evaluate drug stability in the nails. Reference nails containing the four medicines were collected from patients with hay fever who ingested the medicines daily for four months. The nails were exposed to various natural environments for up to four months.

RESULTS

The effects of temperature, humidity, and light on drug contents in the nails were comparatively small. Soil significantly decomposed the nail surfaces and decreased the drug content of the nails (up to 17 %). Water also decreased the drug content (up to 12 %), although no apparent changes in nail surfaces were observed.

CONCLUSIONS

In comparison with hair data obtained under the same environmental conditions, light affected drugs in the hair rather than in nails, whereas water and soil greatly affected drugs in the nails rather than in hair. Although the disposition of drugs incorporated in the tissues differed between nails and hair, the analytes were detected in nails and hair strands left in severe natural environments. MSA could be useful for estimating drug-use histories and personal profiles using the nails and hair of a corpse.

Incorporation of suvorexant and lemborexant into hair and their distributions after a single intake

PURPOSE

This study examined the applicability of hair analysis as an approach to identify suvorexant (SUV) and lemborexant (LEM) intake by analyzing black hair specimens collected from study participants after a single oral administration.

METHODS

Hair specimens were collected form participants who took a single dose of 10 mg SUV or 5 mg LEM. Identification of the dual orexin receptor antagonists (DORAs) and their metabolites was performed by liquid chromatography-tandem mass spectrometry. Reference standards of S-M9 and L-M4, the metabolites of SUV and LEM, respectively, were synthesized in our laboratory. Sectional analysis of 1-mm segments of the single-hair strands was also performed to investigate the incorporation behavior of the drugs into hair.

RESULTS

Unchanged SUV and LEM, and their metabolites S-M9 and L-M4 were detected even in the single-hair specimens. Results of the segmental hair analysis showed predominant incorporation of the drugs into hair through the hair bulb region rather than through the upper dermis zone of the hair root. The drug concentrations in the hair specimens, collected about 1 month after intake, were 0.033-0.037 pg/hair strand (0.17-0.19 pg/mg) for SUV and 0.054-0.28 pg/hair strand (0.28-1.5 pg/mg) for LEM. The calculated distribution ratios of the DORAs into hair to the oral doses were much lower than those of benzodiazepines and zolpidem reported in a previous study.

CONCLUSIONS

This is the first report of the detection of the DORAs in hair. The incorporation behavior of the DORAs into hair revealed herein are crucial for proper interpretation of hair test results.

Application of LC-MS/MS for the Identification of Drugs of Abuse in Driver's License Regranting Procedures

Background: Drugged driving is associated with an increased risk of road accidents worldwide. In Italy, driving under the influence (DUI) of alcohol and drugs is a reason for driving disqualification or revocation of the driving license. Drivers charged with driving under the influence of alcohol and drugs must attend a Local Medical Commission (LMC) to undergo mandatory examinations to regain the suspended license. Our study mainly aims to report on the analysis performed on hair samples collected from 7560 drivers who had their licenses suspended for drugged or drunk driving between January 2019 and June 2024. Methods: A rapid, sensitive, and selective method for the determination of ethyl glucuronide in hair by UPLC/MS-MS was developed and fully validated. Results: The most frequently detected substances were cocaine (ecgonine methyl ester, norcocaine, and benzoylecgonine) and cannabinoids (Δ9-tetrahydrocannabinol, cannabidiol, and cannabinol), followed by opiates (codeine, morphine, and 6-MAM), methadone (EDDP), and amphetamines (amphetamine, methamphetamine, MDA, MDMA, and MDEA). To perform a more in-depth analysis, we also compared hair color with the drug classes that tested positive. The results showed a significant prevalence of dark hair that tested positive for one or more substances, followed by gray/white hair and light hair. Conclusions: Our study provides an interesting and alarming insight into drug exposure in the general population with serious public health threats, discussing the main aspects of hair matrix analysis and focusing on its advantages and reliability in the interpretation of results.

Estimation of the time of zolpidem intake and differentiation between consumption and external contamination using MALDI-MSI for investigations on single hair samples

Estimation of drug ingestion time (event time) and distinguishing between drug ingestion and external contamination are important for interpreting hair analysis results in forensics practice. Here, we present a matrix-assisted laser desorption/ionization-mass spectrometry imaging (MALDI-MSI) method for in situ analysis of intact hair. We applied a longitudinal cutting method for a single hair to analysis authentic hair samples from a victim of a drug-facilitated sexual assault (DFSA) case and zolpidem-soaked hair. MALDI-MSI showed that zolpidem-positive segments distributed at 4-6 mm or 6-8 mm from the root in three single hairs of a DFSA victim collected 25 days after the event, at concentrations ranging from 0.1 to 5.7 pg mm-1, in agreement with the results from segmental analysis using liquid chromatography tandem mass spectrometry (LC-MS/MS). The estimation of drug intake time was about 20-30 days before sampling, which was consistent with the known time of drug intake. This MALDI-MS method allows imaging analysis of trace substances in a single hair and can realize the intuitive reflection of drug taking time. In addition, zolpidem applied by soaking was mainly distributed on both sides of the longitudinal hair shaft, whereas ingested zolpidem was found only in the middle of the hair shaft of the DFSA victim. The MALDI-MS images of unwashed and washed hair suggested that the amount of externally applied drug was decreased by washing, it was still present on surface layer (cuticle) sides although. Visualization using MALDI-MSI could therefore distinguish between drug ingestion and contamination by reflecting the distribution and deposition site of the drug in hair.

Analytical techniques for screening of cannabis and derivatives from human hair specimens

Cannabis and associated substances are some of the most frequently abused drugs across the globe, mainly due to their anxiolytic and euphorigenic properties. Nowadays, the analysis of hair samples has been given high importance in forensic and analytical sciences and in clinical studies because they are associated with a low risk of infection, do not require complicated storage conditions, and offer a broad window of non-invasive detection. Analysis of hair samples is very easy compared to the analysis of blood, urine, and saliva samples. This review places particular emphasis on methodologies of analyzing hair samples containing cannabis, with a special focus on the preparation of samples for analysis, which involves screening and extraction techniques, followed by confirmatory assays. Through this manuscript, we have presented an overview of the available literature on the screening of cannabis using mass spectroscopy techniques. We have presented a detailed overview of the advantages and disadvantages of this technique, to establish it as a suitable method for the analysis of cannabis from hair samples.

Effects of temperature, humidity, light, and soil on drug stability in hair: a preliminary study for estimating personal profiles using micro-segmental analysis of corpse hair

PURPOSE

Micro-segmental hair analysis (MSA), which enables detailed measurement of the distribution of drugs in a single hair strand, is useful for examining the day of death and drug use history of a person. However, corpses are often found in severe environments, such as soil and freezers, which affect the drug contents in hair. Therefore, we examined the effects of temperature, humidity, light, and soil on drug stability in hair as a preliminary study to estimate personal profiles using MSA of corpse hair.

METHODS

Four hay-fever medicines (fexofenadine, epinastine, cetirizine, and desloratadine) were used as model drugs to evaluate drug stability in hair. Reference hair strands consistently containing the four medicines along the hair shaft were collected from patients with hay-fever who ingested the medicines daily for 4 months. The hair strands were placed in chambers with controlled temperatures (- 30 to 60 °C) and relative humidities (ca. 18 % and > 90 %), exposed to light (sunlight and artificial lights) or buried in soil (natural soil and compost).

RESULTS

Sunlight and soil greatly decomposed the hair surfaces and decreased the drug contents in hair (up to 37 %). However, all analytes were successfully detected along the hair shaft, reflecting the intake history, even when the hair was exposed to sunlight for 2 weeks and buried in the soil for 2 months.

CONCLUSIONS

Although the exposure to sunlight and storage in soil for long times made drug-distribution analysis difficult, MSA could be applied even to hair strands collected from corpses left in severe environments.

Maternal hair segments reveal metal(loid) levels over the course of pregnancy: a preliminary study in Southern China

Characterization of metal(loid) variation during pregnancy and identification of the affecting factors are important for assessing pregnancy exposures in epidemiological studies. In this study, maternal hair was collected in three segments (each 3 cm) from pregnant women in Guangzhou, China. Ten metal(loid)s, including six essential trace metal(loid)s and four toxic trace metal(loid)s, were analyzed to investigate the levels of various metal(loid)s during pregnancy and the factors that influence them. Strong pairwise correlations were observed between manganese (Mn), cobalt (Co), and vanadium (V), between selenium (Se), arsenic (As), and antimony (Sb), and between cadmium (Cd) and lead (Pb). All metal(loid)s except for Se, Mn, and Co showed strong correlations among the three hair segments, and most of the metal(loid)s had good reproducibility, with intraclass correlation coefficients (ICCs) ranging from 0.510 to 0.931, except for As (ICC = 0.334), Mn (ICC = 0.231), and Co (ICC = 0.235). Zn levels decreased, while Sb increased, in maternal hair during pregnancy. Maternal sociodemographic characteristics and dietary intake affected metal(loid) levels in maternal hair. These results provide foundational data for using maternal hair segmental analysis to evaluate exposure variation to metal(loid)s during pregnancy and the potential factors associated with them.

Segmental analysis and long-term monitoring of vadadustat in equine hair for the purpose of doping control

Vadadustat is a newly launched hypoxia-inducible factor stabilizer with anti-anemia and erythropoietic effects; however, its use in horses is expressly forbidden in both racing and equestrian competitions. Following our previous report on the pharmacokinetic study of vadadustat in horse plasma and urine, a long-term longitudinal analysis of vadadustat in horse hair after nasoesophageal administration (3 g/day for 3 days) to three thoroughbred mares is described in this study. Our main objective is to further extend the detection period of vadadustat for the purpose of doping control. Three bunches of mane hair from each horse were collected at 0 (pre), 1, 2, 3 and 6 month(s) post-administration. These hair samples were each cut into 2-cm segments and pulverized after decontamination of hair samples. The analyte in the powdered hair samples was extracted with liquid-liquid extraction followed by further purification by solid-phase extraction with strong anion exchange columns. The amount of vadadustat incorporated into the hair was quantified with a newly developed and validated method using liquid chromatography-high-resolution mass spectrometry. Our results show that vadadustat was confirmed in all post-administration hair samples, but its metabolites were not present. Thus, the detection window for vadadustat could be successfully extended up to 6 months post-administration. Interestingly, the 2-cm segmental analysis revealed that the tip of the drug band in the hair shifted along with the hair shafts in correspondence with the average hair growth rate (∼2.5 cm/month) but gradually diffused more widely from 2 cm at 1 month post-administration to up to 14 cm at 6 months post-administration. However, the loss in the total amount of vadadustat in hair over time was observed to most likely be due to the degradation of vadadustat. These findings will be useful for the control of abuse and/or misuse of vadadustat and the interpretation of positive doping cases.

Evaluation of applicability of micro-segmental analysis to hair treated with heat and haircare products

PURPOSE

Micro-segmental analysis (MSA), which enables the measurement of detailed drug distributions in hair by segmenting a single hair strand at 0.4 mm intervals, is indispensable for estimating the day of drug ingestion. However, haircare with dryers and various products can influence drug concentrations in hair. Therefore, the applicability of MSA to hair that was treated with heat or various haircare products was evaluated.

METHODS

Reference hair strands containing drugs consistently along the hair shafts were collected from patients who ingested four hay-fever medicines (fexofenadine, epinastine, cetirizine, and loratadine) daily for 4 months. The hair strands were divided into eight 4 mm regions from the proximal end, and each region was placed on an electric hot plate at 100-200 °C or soaked in haircare products, such as shampoo and bleaching agent. The hair regions were subjected to MSA. Moreover, after a patient was administered midazolam at a single dose and the hair was bleached, the day of midazolam administration was estimated using MSA.

RESULTS

Repetitive heating for 1 min and daily haircare products, such as shampoo, hardly affected the drugs in hair, whereas bleaching products containing H2O2 decreased the amounts of hay-fever medicines in the hair up to 58%. However, the amount of midazolam did not decrease in bleached hair and the day of midazolam administration was successfully estimated.

CONCLUSIONS

The analytes used in this study were minimally affected by ordinary haircare and could be detected even in bleached hair. Therefore, MSA can be applicable regardless of haircare history.

Challenges and future trends in wearable closed-loop neuromodulation to efficiently treat methamphetamine addiction

Achieving abstinence from drugs is a long journey and can be particularly challenging in the case of methamphetamine, which has a higher relapse rate than other drugs. Therefore, real-time monitoring of patients' physiological conditions before and when cravings arise to reduce the chance of relapse might help to improve clinical outcomes. Conventional treatments, such as behavior therapy and peer support, often cannot provide timely intervention, reducing the efficiency of these therapies. To more effectively treat methamphetamine addiction in real-time, we propose an intelligent closed-loop transcranial magnetic stimulation (TMS) neuromodulation system based on multimodal electroencephalogram-functional near-infrared spectroscopy (EEG-fNIRS) measurements. This review summarizes the essential modules required for a wearable system to treat addiction efficiently. First, the advantages of neuroimaging over conventional techniques such as analysis of sweat, saliva, or urine for addiction detection are discussed. The knowledge to implement wearable, compact, and user-friendly closed-loop systems with EEG and fNIRS are reviewed. The features of EEG and fNIRS signals in patients with methamphetamine use disorder are summarized. EEG biomarkers are categorized into frequency and time domain and topography-related parameters, whereas for fNIRS, hemoglobin concentration variation and functional connectivity of cortices are described. Following this, the applications of two commonly used neuromodulation technologies, transcranial direct current stimulation and TMS, in patients with methamphetamine use disorder are introduced. The challenges of implementing intelligent closed-loop TMS modulation based on multimodal EEG-fNIRS are summarized, followed by a discussion of potential research directions and the promising future of this approach, including potential applications to other substance use disorders.

Epiglottis Cartilage, Costal Cartilage, and Intervertebral Disc Cartilage as Alternative Materials in the Postmortem Diagnosis of Methanol Poisoning

Alternative materials for postmortem diagnosis in the case of fatal poisonings are much needed when standard materials, such as blood and urine, are unavailable. The study presents a case of fatal mass methanol intoxication resulting from industrial alcohol consumption. The study aimed to determine methanol and formic acid concentrations in epiglottis cartilage, costal cartilage, and intervertebral disc cartilage and to analyze the correlation between their concentrations in cartilage tissues and the femoral blood. Methanol and formic acid concentrations in samples collected from 17 individuals (n = 17) were estimated using gas chromatography with flame ionization detection (GC-FID). Methanol concentration in the costal cartilage correlated with its concentration in the femoral blood (r = 0.871). Similar correlations were found for epiglottis cartilage (r = 0.822) and intervertebral disc cartilage (r = 0.892). Formic acid concentration in the blood correlated only with its concentration in urine (r = 0.784) and the epiglottis (r = 0.538). Cartilage tissue could serve as an alternative material for methanol analyses in postmortem studies. Formic acid, a methanol metabolite, does not meet the requirements for its presence determination in cartilage tissues.