Estimation of day of death using micro-segmental hair analysis based on drug use history: a case of lidocaine use as a marker

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.

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.

Micro-segmental analysis of the entry pathway and distribution of zolpidem in hair from different scalp regions after a single dose

Introduction: Hair testing is well established for the assessment of past drug exposure; however, more research is needed to understand drug incorporation mechanisms and drug entry pathways into hair. Method: In this study, a micro-segmental LC-MS/MS method was used to analyze a 0.4 mm segment of hair after a single oral administration of zolpidem. Five single hairs were plucked at 1 day, 3 days, 7 days, and 28 days after administration from the vertex posterior of three subjects, and 5 single hairs were also plucked from the parietal, left temporal, and right temporal regions of the head at 28 days. Results and discussion: Proximal S1 (0-0.4 mm) in hair plucked at 1 day had the highest level of zolpidem at 1.5-2.4 pg/mm; much lower concentrations (< 1 pg/mm) were detected at proximal S2-S8 (0.4-3.2 mm). The drug concentration decreased gradually in S1 for 7 days after drug intake and disappeared by 28 days, suggesting that the drug from the bloodstream initially combined with the hair follicle and then gradually moved to the hair tip as the hair grew. The zolpidem concentration-hair segment profiles exhibited a large peak (root side) and a small peak (tip side) for the four sampling times in all three subjects, indicating that drug incorporation in the hair bulb occurred mainly from the blood but probably also entered the hair through sweat and sebum. Zolpidem was also detected in all hairs from the vertex posterior in all three subjects but was not detected in 1 hair from the parietal region and 2 hairs from the left temporal region. The consistency in drug detection, drug concentration level, and peak position was better in hair from the vertex posterior than from the other three regions, indicating that the vertex posterior is a suitable sampling region for estimating drug intake.

Possibility of drug-distribution measurement in the hair of drowned bodies: evaluation of drug stability in water-soaked hair using micro-segmental analysis

In postmortem examinations, the drug analysis of hair is effective for revealing drug-use history. Additionally, a method to estimate the day of death using hair was previously developed by analyzing a single hair strand segmented at 0.4-mm intervals (micro-segmental hair analysis). However, for drowned bodies, drugs in the hair may be washed out due to soaking in water for extended periods. To evaluate the possibility of measuring drug distribution in the hair of drowned bodies, drug stability in hair samples soaked in various aqueous solutions was examined. First, reference hair strands of drug users containing specific drugs consistently along the hair shaft were prepared. The participants ingested 4 hay-fever medicines (fexofenadine, epinastine, cetirizine, and loratadine) every day for approximately 4 months before hair collection. Each reference strand was divided into regions, and each region was soaked in different solutions containing various solutes for extended periods up to approximately 2 months. In solutions without divalent ions (Ca²⁺ and Mg²⁺), the drug content in the hair decreased up to approximately 5 % with increasing salt concentration and soaking time. However, the decreased drug content was negligible in solutions containing divalent ions, implying that the divalent ions prevented drugs contained in hair from washing out. As natural river and sea waters contain divalent ions, the drugs in hair were hardly washed out even when the hair was soaked for 2 months. Thus, it was concluded that drug-distribution measurements using micro-segmental analysis can also be applied to the hairs of drowned bodies.

Time course of estazolam in single-strand hair based on micro-segmental analysis after controlled oral administration

The mechanism of estazolam incorporation into hair was investigated by studying the time course of estazolam along single-strand hair after two oral administration of estazolam at 28 days interval. Estazolam in single hair segments 0.4 mm in length was verified and quantified by ultra-high-performance liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS). The distributions of estazolam within a strand of hair (collected at 12 h, 28 days, and 56 days post-administration) were visualized by micro-segmental analysis. The highest estazolam concentration (1.5-9.9 pg/mm) was detected in the hair bulb region (S1), and it then decreased through the hair shaft to the distal end, with a small fluctuation (0.3-3 pg/mm) near the junction of the hair roots and shafts (S4-S7) 12 h after drug intake. These findings suggested that the incorporation of estazolam occurred in two regions, mainly in the hair bulb and to a lesser extent in the upper dermis zone. Models using internal temporal markers (TIMs) and temporal intervals (TIs) were constructed to estimate the day of estazolam ingestion. The estimation accuracy was within an average error of 1.7 mm and 3.0 mm between the calculated and actual positions, based on the TIMs and TIs 56 days after estazolam intake. These findings can help in further elucidation of the drug incorporation mechanism, which is crucial for interpreting hair analysis results used to reveal individual drug-use history.

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

PURPOSE

Since the 1980s, the detection sensitivity of mass spectrometers has increased by improving the analysis of drugs in hair. Accordingly, the number of hair strands required for the analysis has decreased. The length of the hair segment used in the analysis has also shortened. In 2016, micro-segmental hair analysis (MSA), which cuts a single hair strand at a 0.4-mm interval corresponding to a hair growth length of approximately one day, was developed. The advantage of MSA is that the analytical results provide powerful evidence of drug use in the investigation of drug-related crimes and detailed information about the mechanism of drug uptake into hair. This review article focuses on the MSA technique and its applications in forensic toxicology.

METHODS

Multiple databases, such as SciFinder, PubMed, and Google, were utilized to collect relevant reports referring to MSA and drug analysis in hair. The experiences of our research group on the MSA were also included in this review.

RESULTS

The analytical results provide a detailed drug distribution profile in a hair strand, which is useful for examining the mechanism of drug uptake into hair in detail. Additionally, the analytical method has been used for various scenarios in forensic toxicology, such as the estimation of days of drug consumption and death.

CONCLUSIONS

The detailed procedures are summarized so that beginners can use the analytical method in their laboratories. Moreover, some application examples are presented, and the limitations of the current analytical method and future perspectives are described.

Distribution profiles of diphenhydramine and lidocaine in scalp, axillary, and pubic hairs measured by micro-segmental hair analysis: good indicator for discrimination between administration and external contamination of the drugs

Purpose

Drug distribution in scalp hair can provide historical information about drug use, such as the date and frequency of drug ingestion. We previously developed micro-segmental hair analysis, which visualizes drug distribution at 0.4-mm intervals in individual hairs. The present study examines whether the distribution profiles of drugs can be markers for the administration or external contamination of the drugs using scalp, axillary, and pubic hairs.

Methods

A single dose of anti-itch ointment containing diphenhydramine (DP) and lidocaine (LD) was topically applied to the axillary or pubic areas of two volunteers; DP was also orally administered; and LD was intra-gingivally injected. Scalp, axillary, and pubic hairs were assessed using our micro-segmental analysis.

Results

The localization of DP and LD differed within individual scalp hair strands, implying DP and LD were predominantly incorporated into scalp hair via the bloodstream and via sweat/sebum, respectively, showing double-peak profiles. However, DP and LD were distributed along the shafts of axillary and pubic hairs without appearance of the double-peak profiles when the ointment had been applied to the axillary and pubic areas. The distributions of DP and LD in scalp hairs did not significantly differ according to administration routes, such as oral administration, gingival injection, and topical application.

Conclusions

Micro-segmental analysis revealed differences in the distribution profiles of drugs in hairs, and distinguished hairs with and without external contamination. These findings will be useful for understanding of the mechanism of drug uptake into hair and for estimating the circumstances for a drug use.

Identification of furosemide in hair in a post-mortem case by UHPLC-MS/MS with guidance on interpretation

Testing for drugs in hair raises several difficulties. Among them is the interpretation of the final concentration(s). In a post-mortem case, analyses revealed the presence of furosemide (12 ng/mL) in femoral blood, although it was not part of the victim's treatment. The prosecutor requested our laboratory to undertake an additional analysis in hair to obtain information about the use of furosemide. A specific method was therefore developed and validated to identify and quantify furosemide in hair by UHPLC-MS/MS. After decontamination of 30 mg of hair, incubation in acidic condition, extraction with ethyl acetate, the samples were analyzed by UHPLC-MS/MS. Furosemide was found in the victim's hair at 225 pg/mg. However, it was not possible to interpret this concentration due to the absence of data in the literature. Therefore, the authors performed a controlled study in two parts. In order to establish the basis of interpretation, several volunteers were tested (four after a single 20 mg administration and twenty-four under daily treatment). The first part indicated that a single dose is not detectable in hair using our method. The second part demonstrated concentrations ranging from 5 to 1110 pg/mg with no correlation between dosage and hair concentrations. The decedent's hair result was interpreted as repeated exposures. In the case of furosemide analysis, hair can provide information about its presence but cannot give information about dosage or frequency of use.

UPLC–MS/MS simultaneous determination of methamphetamine, amphetamine, morphine, monoacetylmorphine, ketamine, norketamine, MDMA, and MDA in hair

Hair is a stable specimen and has a longer detection window (from weeks to months) than blood and urine. Through the analysis of hair, the long-term information of the drug use of the identified person could be explored. Our work is to establish an ultra-performance liquid chromatography–tandem mass spectroscopy (UPLC–MS/MS) method for simultaneous determination of methamphetamine, amphetamine, morphine, monoacetylmorphine, ketamine, norketamine, 3,4-methylenedioxymethamphetamine (MDMA), and 3,4-methylenedioxyamphetamine (MDA) in hair. Methoxyphenamine was used as an internal standard. The chromatographic separation was performed on a UPLC ethylene bridged hybrid (BEH) C18 (2.1 mm × 50 mm, 1.7 μm) column using a mobile phase of acetonitrile–water with 10 mmol/L ammonium acetate solution which containing 0.05% ammonium hydroxide. The multiple reaction monitoring in positive electrospray ionization was used for quantitative determination. The intra-day and inter-day precisions (relative standard deviation [RSD]) were below 15%. The accuracy ranged between 85.5% and 110.4%, the average recovery rate was above 72.9%, and the matrix effect ranged between 92.7% and 109.2%. Standard curves were in the range of 0.05–5.0 ng/mg, and the correlation coefficients were greater than 0.995. The established UPLC–MS/MS method was applied to analyze the hair samples successfully.