Development of a method to evaluate the effects of external environments on drug stability in nails using micro-segmental analysis

Nails can be used as an alternative to hair for examining past drug use. However, daily hand-and-nail care can eliminate the internal drugs. Therefore, we developed an evaluation method to examine the effects of the external environment on drug stability in nails using micro-segmental analysis. First, reference nails containing drugs were prepared by collecting fingernails from participants who had consumed hay-fever medicines continuously for 4 months. Next, the entire free edge of a reference nail was cut into halves at the centerline; one side was stored as an untreated block, and the other was treated with various hand/nail care products. Both nail blocks were washed and segmented at 0.5-mm intervals in the width direction. Each segment in the extraction solution was crushed with stainless-steel beads, sonicated, and soaked in the solution for 24 h. The analytes in extracts were quantified by LC-MS/MS, and the drug concentrations between the treated and untreated blocks were compared. The drug concentrations decreased slightly in nails treated with manicure and gel-nail products. The analytes in nails tended to be lower in water-rich products such as hand soap and hand cream than in oil-rich products such as nailcare oil and acetone-free remover. The developed method using micro-segmental analysis enabled the evaluation of the effects of various hand/nail care products on drug stability in a limited number of nails. This would also be useful for examining the effects of severe environments on drugs in nails collected from cases of unnatural death.

COL1A2 Barcoding: Bone Species Identification via Shotgun Proteomics

Species identification of fragmentary bones remains a challenging task in archeology and forensics. A species identification method for such fragmentary bones that has recently attracted interest is the use of bone collagen proteins. Here, we describe a method similar to DNA barcoding that reads collagen protein sequences in bone and automatically determines the species by performing sequence database searches. The method is almost identical to conventional shotgun proteomics analysis of bone samples, except that the database used by the SEQUEST search engine consisted only of entries for collagen type 1 alpha 2 (COL1A2) proteins from various vertebrates. Accordingly, the COL1A2 peptides that differ in sequence among species act as species marker peptides. In SEQUEST-based shotgun proteomics, the protein entries that contain more marker peptide sequences are assigned higher scores; therefore, the highest-scoring protein entry will be the COL1A2 entry for the species from which the analyzed bone was derived. We tested our method using bone samples from 30 vertebrate species and found that all species were correctly identified. In conclusion, COL1A2 can be used as a bone protein barcode and can be read through shotgun proteomics, allowing for automatic bone species identification. Data are available via ProteomeXchange with the identifier PXD045402.

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.

Simultaneous analysis of degradation products of Novichok agents and conventional nerve agents in human urine by ion chromatography-tandem mass spectrometry using ammonium regeneration solution

An ion chromatography (IC)-tandem mass spectrometry (MS/MS) method to analyze nerve agent degradation products in human urine was developed. Six degradation products of conventional nerve agents and six Novichok agent degradation products were analyzed simultaneously despite their differences in hydrophilicity and acidity. Using ammonium regeneration solution improved the peak shapes greatly compared with the results obtained with the ordinary IC-MS/MS configuration. For urine samples, a simple pretreatment method of dilution with water and ultrafiltration was used. The detection limits of the nerve agent degradation products were sufficiently low (10-250 ng/mL) and the calibration curves showed acceptable linearity. Due to the absence of a derivatization step, throughput was higher than for our previous derivatization-liquid chromatography-MS/MS method.

Advances in Derivatization Techniques Enabled by DABCO for Novichok Agent Analysis in Biofluids Using LC-MS

The characterization of Novichoks (NVs), a new group of nerve agents that have been implicated in two recent poisonings, has not been extensively conducted. Here, we present a novel method for analyzing NV hydrolysates using liquid chromatography-tandem mass spectrometry (LC-MS/MS) enabled by pentafluorobenzyl (PFB) derivatization followed by reaction with 1,4-diazabicyclo[2.2.2]octane (DABCO). This approach enabled efficient, simultaneous screening of six NV hydrolysates, with 1-2 orders improvement in the limit of detection in relation to that achieved through previous methods. A straightforward pretreatment using DABCO and filtration was employed for biological samples, mitigating instrument damage and allowing LC-MS/MS after a reaction with highly hydrophobic PFB bromide (PFBBr). In addition, the use of pralidoxime (PAM) significantly enhanced the detection of NV hydrolysates from NV-surrogate-spiked serum. While PAM is not a proven NV antidote, its effectiveness as an analytical reagent to aid in the detection of NV hydrolysates was demonstrated for the first time. Understanding the proposed mechanism of DABCO-mediated derivatization reagent removal in this research could broaden the range of compounds amenable to derivatization LC, thereby enhancing the capabilities of conventional derivatization techniques.

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.

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.

Analysis of degradation products of nerve agents in biological fluids by ion chromatography-tandem mass spectrometry

PURPOSE

The detection of hydrolysis products of nerve agents (alkyl methylphosphonic acids; RMPAs) in biological samples from victims is important to confirm exposure to nerve agents. However, analysis of RMPAs is difficult due to their high hydrophilicity. The aim of this study was to develop ion chromatography-tandem mass spectrometry (IC-MS/MS) methods using commercially available equipment and columns to analyze RMPAs in human urine and serum with high sensitivity and without using complicate techniques.

METHODS

A Dionex IonPac AS11-HC anion-exchange column was used to analyze six RMPAs (MPA, EMPA, IMPA, ⁱBuMPA, CHMPA, and PMPA). For pretreatments of biological fluids, we developed two pretreatment methods (Method 1: dilution and ultrafiltration; Method 2: removal of chloride ions with Ag cartridges).

RESULTS

Six RMPAs including highly hydrophilic methylphosphonic acid and ethyl methylphosphonic acid could be analyzed with sufficient retention times and peak shape. The detection limits of RMPAs were improved using Dionex OnGuard II Ba/Ag/H cartridges and MetaSEP IC-Ag cartridges (urine: 0.5-5 ng/mL; serum: 1-5 ng/mL). These methods were also applied to the test samples for the Organisation for the Prohibition of Chemical Weapons Biomedical Proficiency Tests.

CONCLUSIONS

RMPAs could be sufficiently analyzed by IC-MS/MS. In addition, the limits of detection were superior to those obtained in our previous study involving LC-MS/MS or derivatization-LC-MS/MS method. For analysis of biological samples, an appropriate pretreatment method can be chosen according to the amount of sample available for analysis and expected RMPA concentrations.

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.

Dimethoxytriadinylation LC-MS/MS of Novichok A-Series Degradation Products in Human Urine

Novichok A-series compounds, novel nerve agents, pose an increasing threat to citizens worldwide; however, no analytical methods have been reported for detecting their hydrolysis products. Herein, a screening method was developed to detect and identify Novichok A-series degradation products (hydrolysates of A230, A232, A234, A262, and one related compound) and alkyl methylphosphonic acids (RMPAs, conventional nerve agent hydrolysates) using liquid chromatography-tandem mass spectrometry (LC-MS/MS). We identified a suitable derivatization reagent, 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride (DMTMM), and optimized the reaction conditions. The derivatized esters of Novichok A-series degradation products were stable and easily detected. We used this derivatization to achieve the first analytical method for Novichok hydrolysis products in urine (0.40-4.0 ng/mL). The detection limits of the RMPAs (0.1-0.4 ng/mL) were comparable to those presented in previous reports involving pentafluorobenzylation or direct LC-MS/MS. The applicability of the newly developed method was evaluated by analyzing urine samples from the OPCW Fifth Biomedical Proficiency Test.

Assembly of Glycochips with Mammalian GSLs Mimetics toward the On-site Detection of Biological Toxins

According to our previously proposed scheme, each of three kinds of glycosphingolipid (GSL) derivatives, that is, lactosyl ceramide [Lac-Cer (1)] and gangliosides [GM1-Cer (2) and GT1b-Cer (3)], was installed onto the glass surface modified with Au nanoparticles. In the present study, we tried to apply microwave irradiation to promote their installing reactions. Otherwise, this procedure takes a lot of time as long as a conventional self-assembled monolayer (SAM) technique is applied. Using an advanced microwave reactor capable of adjusting ambient temperatures within a desired range, various GSL glycochips were prepared from the derivatives (1)-(3) under different microwave irradiation conditions. The overall assembling process was programed with an IC controller to finish in 1 h, and the derived GSL glycochips were evaluated in the analysis of three kinds of biological toxins [a Ricinus agglutinin (RCA₁₂₀), botulinum toxin (BTX), and cholera toxin (CTX)] using a localized surface plasmon resonance (LSPR) biosensor. In the LSPR analysis, most of the irradiated GSL chips showed an enhanced response to the targeting toxin when they were irradiated under optimal temperature conditions. Lac-Cer chips showed the highest response to RCA₁₂₀ (an agglutinin with β-_D-Gal specificity) when the microwave irradiation was conducted at 30-35 °C. Compared to our former Lac-Cer glycochips with the conventional SAM condition, their response was enhanced by 3.6 times. Analogously, GT1b chips gained an approximately 4.1 times enhancement in their response to botulinum type C toxin (BTX/C) when the irradiation was conducted around at 45-60 °C. In the LSPR evaluation of the GM1-Cer glycochips using CTX, an optimal condition also appeared at around 30-35 °C. On the other hand, the microwave irradiation did not lead to a notable increase compared to the former GM1-Cer chips derived with the SAM technique. Judging from these experimental results, the microwave irradiation effectively promotes the installing process for all the three kinds of the GSL derivatives, while the optimal thermal condition becomes different from each other. Many bacterial and botanic proteinous toxins are composed of such carbohydrate binding domains or subunits that can discriminate both the key epitope structure and the dimension of glycoconjugates on the host cell surface. It is assumed that the optimal irradiation and thermal conditions are required to array these semi-synthetic GSL derivatives on the Au nanoparticles in a proper density and geometry for tight adhesion with each of the biological toxins.

Paper-Based Analytical Device for the On-Site Detection of Nerve Agents

We report a colorimetric paper-based microfluidic device based on an enzyme inhibition assay that allows the on-site detection of nerve agents by sampling and wicking. The sample and reagents are automatically transported through the channel where an enzyme inhibition reaction is conducted, followed by an enzyme-substrate reaction and a color reaction. This device can detect 0.1 μg/mL of the nerve agent VX in a 2.5 μL drop and is nerve agent selective and robust against temperature, pH, and several liquids. We confirmed that sampling procedures (dilution and wiping) are applicable to this device. Furthermore, the fabrication procedure is easy, and the cost is at most a few tens of cents. Thus, the present device provides a practical method for the urgent detection of nerve agents in suspected chemical terrorism incidents.

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.

A Screening Method for Cyanide in Blood by Dimethoxytriazinyl Derivatization-GC/MS

A simple screening analysis of cyanide in blood has been developed, using 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride (DMTMM). DMTMM, a convenient reagent for dehydrocondensation, converted cyanide to 2-cyano-4,6-dimethoxy-1,3,5-triazine, the dimethoxytriazinyl derivative of cyanide. This reaction proceeded in whole blood samples after treatment with trichloroacetic acid, and in basic aqueous solution samples. Sufficient sensitivity was observed by the method using gas chromatography/mass spectrometry. Intra- and inter-day repeated analyses (0.05, 0.1, 0.25, 1 and 5 μg/mL, n = 5) were performed and the accuracy and precision were within 20% for the lower limit of quantification (LLOQ) and within 15% for other concentrations. LLOQs for the aqueous solution and blood were 0.05 and 0.1 μg/mL, respectively, which are suitable for detecting cyanide poisoning. The limits of detection (signal-to-noise ratio ≥ 3) for aqueous solution and blood were 0.01 and 0.05 μg/mL, respectively. Interference from 13 other anions was tested and no false positive response was obtained, even in the case of thiocyanate, nitrite and nitrate, which are known to yield cyanide by acid treatment of blood. This method is practical because it uses readily available reagents and equipment and is sensitive enough for the rapid screening of cyanide poisoning in forensic and clinical toxicology.

Development of an improved method to estimate the days of continuous drug ingestion, based on the micro-segmental hair analysis

To prove drug-related crimes, it is important to estimate the date on which a specific drug was ingested. Previously, we developed a method, "micro-segmental hair analysis," to estimate the day of ingestion of a single-dose drug by segmenting a hair strand into 0.4-mm segments, which correspond to daily hair growth. In this study, the method was improved to estimate the days of continuous drug ingestion. The subjects ingested four hay-fever medicines (fexofenadine, epinastine, cetirizine, and loratadine) continuously (1-18 days) and chlorpheniramine as a single dose at intervals of several weeks as an internal temporal marker (ITM). The hair strands of the subjects were collected and subjected to a micro-segmental analysis. The distribution curves of each hay-fever medicine in a hair strand had broad peaks reflecting the number of days of drug ingestion. The positions on the curves corresponding to the first and final ingestion days of hay-fever medicines were identified using the ITM. The positions were near the hair segments on both ends of full width at half maximum (W₂ ) of the broad peak. When the first and final days of continuous ingestion were estimated using W₂ , independent of peak shape, the absolute average error from the actual ingestion days was approximately 2 days. Overall, we established a method to estimate the days of both single-dose and continuous drug ingestions. Furthermore, the method would be useful to investigate drug ingestion history in various scenes such as drug-related crimes and therapeutic drug monitoring.

Analysis of nitrogen mustard degradation products via post-pentafluorobenzoylation liquid chromatography-tandem mass spectrometry

A pentafluorobenzoylation (PFBz)-liquid chromatography-tandem mass spectrometry method was developed for qualitative and quantitative analysis of ethanolamines (EAs, nitrogen mustard degradation products). With this method, highly hydrophilic EAs can be sufficiently analyzed with a commonly used reversed phase column (retention times: (PFBz)₂-methyl diethanolamine, 9.1 min; (PFBz)₂-ethyl diethanolamine, 9.8 min; and (PFBz)₃-triethanolamine, 17.6 min). The applicability of the method for real samples was investigated via recovery tests. Methyl diethanolamine and ethyl diethanolamine were detected at concentrations as low as 1 ng/mL in serum and 10 ng/mL in urine, and quantified within the range of 1-1000 ng/mL and 10-1000 ng/mL, respectively.

Analysis of degradation products of nitrogen mustards via hydrophilic interaction liquid chromatography-tandem mass spectrometry

A hydrophilic interaction liquid chromatography-tandem mass spectrometry (HILIC-MS/MS) method was developed for qualitative and quantitative analysis of ethanolamines (EAs), which are nitrogen mustard degradation products. With this method, the retention times of the highly hydrophilic EAs on the HILIC column were sufficient (retention times: methyl diethanolamine, 12.2 min; ethyl diethanolamine, 11.2 min; and triethanolamine, 9.5 min) and the EAs were analyzed more efficiently than with reported HILIC-MS/MS methods. The detection limits of methyl diethanolamine and ethyl diethanolamine in serum and urine using this approach were 15-20 ng/mL. The suitability of the method for real samples was evaluated via recovery tests involving urine and serum, and the method was validated. The MS/MS fragmentation of EAs was discussed based on density functional theory calculations.

Analysis of degradation products of nerve agents via post-pentafluorobenzylation liquid chromatography-tandem mass spectrometry

In the work reported here, a screening procedure was developed for the detection and identification of RMPAs (nerve agent degradation products) after pentafluorobenzylation using liquid chromatography-tandem mass spectrometry (LC-MS/MS). With this method, all RMPAs, including highly hydrophilic types such as methylphosphonic acid (MPA) and ethyl methylphosphonic acid (EMPA), were sufficiently retained in commonly used reversed-phase columns (retention times: 15.7 and 11.0 min.), and the presence of RMPAs was determined more efficiently than with the conventional direct LC-MS/MS method. The detection limits of RMPAs using this approach (<33 ng) were mostly superior to those observed with direct LC-MS/MS (<74 ng) and gas chromatography-mass spectrometry (GC-MS) after pentafluorobenzylation (<1.1 μg). The applicability of newly developed method toward real samples was evaluated via recovery tests involving urine/serum and wipe tests on various surfaces.

Accurate Estimation of Drug Intake Day by Microsegmental Analysis of a Strand of Hair by Use of Internal Temporal Markers

Background

Segmental hair analysis can be useful for estimating the time of drug intake. However, this estimation is currently only accurate to within several months. We previously conducted microsegmental analysis of a strand of hair to visualize drug distribution at a spatial resolution of 0.4 mm, which corresponds to daily hair-growth length. Herein, we describe a procedure for accurately estimating the day of drug intake by using internal temporal markers (ITMs) to mark a timescale in the analyzed strand of hair.

Methods

Five drugs were administered in a single dose to the subjects, and then administration was stopped for several weeks. Two subsequent cycles of drug administration and similar withdrawal were performed. For analysis, a strand of hair was plucked from the subject's scalp. The first intake day was considered as the unknown and the drugs administered second and third were regarded as the ITMs. The first intake day was estimated based on the distance from hair root end to 3 drug peaks and 3 known days (hair sampling and 2 ITM cycles).

Results

The drug concentration–hair segment curve had 3 peaks, which reflected the 3 drug cycles. The use of ITMs reduced the error of the true intake day to within 2 days, because the growth rate of the analyzed strand of hair was accounted for by the 2 ITMs.

Conclusions

The estimated accuracy showed little dependency on drug and individual variation. This procedure for estimating the time of drug intake down to a particular day can be used in drug-related crimes, drug abuse and compliance, and for medical diagnosis.

Accurate Estimation of Drug Intake Day by Microsegmental Analysis of a Strand of Hair by Use of Internal Temporal Markers

BACKGROUND

Segmental hair analysis can be useful for estimating the time of drug intake. However, this estimation is currently only accurate to within several months. We previously conducted microsegmental analysis of a strand of hair to visualize drug distribution at a spatial resolution of 0.4 mm, which corresponds to daily hair-growth length. Herein, we describe a procedure for accurately estimating the day of drug intake by using internal temporal markers (ITMs) to mark a timescale in the analyzed strand of hair.

METHODS

Five drugs were administered in a single dose to the subjects, and then administration was stopped for several weeks. Two subsequent cycles of drug administration and similar withdrawal were performed. For analysis, a strand of hair was plucked from the subject's scalp. The first intake day was considered as the unknown and the drugs administered second and third were regarded as the ITMs. The first intake day was estimated based on the distance from hair root end to 3 drug peaks and 3 known days (hair sampling and 2 ITM cycles).

RESULTS

The drug concentration-hair segment curve had 3 peaks, which reflected the 3 drug cycles. The use of ITMs reduced the error of the true intake day to within 2 days, because the growth rate of the analyzed strand of hair was accounted for by the 2 ITMs.

CONCLUSIONS

The estimated accuracy showed little dependency on drug and individual variation. This procedure for estimating the time of drug intake down to a particular day can be used in drug-related crimes, drug abuse and compliance, and for medical diagnosis.

Micro-segmental hair analysis for proving drug-facilitated crimes: Evidence that a victim ingested a sleeping aid, diphenhydramine, on a specific day

Sleeping aids are often abused in the commission of drug-facilitated crimes. Generally, there is little evidence that a victim ingested a spiked drink unknowingly because the unconscious victim cannot report the situation to the police immediately after the crime occurred. Although conventional segmental hair analysis can estimate the number of months since a targeted drug was ingested, this analysis cannot determine the specific day of ingestion. We recently developed a method of micro-segmental hair analysis using internal temporal markers (ITMs) to estimate the day of drug ingestion. This method was based on volunteer ingestion of ITMs to determine a timescale within individual hair strands, by segmenting a single hair strand at 0.4-mm intervals, corresponding to daily hair growth. This study assessed the ability of this method to estimate the day of ingestion of an over-the-counter sleeping aid, diphenhydramine, which can be easily abused. To model ingestion of a diphenhydramine-spiked drink unknowingly, each subject ingested a dose of diphenhydramine, followed by ingestion of two doses of the ITM, chlorpheniramine, 14days apart. Several hair strands were collected from each subject's scalp several weeks after the second ITM ingestion. Diphenhydramine and ITM were detected at specific regions within individual hair strands. The day of diphenhydramine ingestion was estimated from the distances between the regions and the days of ITM ingestion. The error between estimated and actual ingestion day ranged from -0.1 to 1.9days regardless of subjects and hair collection times. The total time required for micro-segmental analysis of 96 hair segments (hair length: 3.84cm) was approximately 2days and the cost was almost the same as in general drug analysis. This procedure may be applicable to the investigation of crimes facilitated by various drugs.

Improved Polymerase Chain Reaction-restriction Fragment Length Polymorphism Genotyping of Toxic Pufferfish by Liquid Chromatography/Mass Spectrometry

An improved version of a polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) method for genotyping toxic pufferfish species by liquid chromatography/electrospray ionization mass spectrometry (LC/ESI-MS) is described. DNA extraction is carried out using a silica membrane-based DNA extraction kit. After the PCR amplification using a detergent-free PCR buffer, restriction enzymes are added to the solution without purifying the reaction solution. A reverse-phase silica monolith column and a Fourier transform high resolution mass spectrometer having a modified Kingdon trap analyzer are employed for separation and detection, respectively. The mobile phase, consisting of 400 mM 1,1,1,3,3,3-hexafluoro-2-propanol, 15 mM triethylamine (pH 7.9) and methanol, is delivered at a flow rate of 0.4 ml/min. The cycle time for LC/ESI-MS analysis is 8 min including equilibration of the column. Deconvolution software having an isotope distribution model of the oligonucleotide is used to calculate the corresponding monoisotopic mass from the mass spectrum. For analysis of oligonucleotides (range 26-79 nucleotides), mass accuracy was 0.62 ± 0.74 ppm (n = 280) and excellent accuracy and precision were sustained for 180 hr without use of a lock mass standard.

Next-generation sequencing analysis of off-ladder alleles due to migration shift caused by sequence variation at D12S391 locus

In short tandem repeat (STR) analysis, length polymorphisms are detected by capillary electrophoresis (CE). At most STR loci, mobility shift due to sequence variation in the repeat region was thought not to affect the typing results. In our recent population studies of 1501 Japanese individuals, off-ladder calls were observed at the D12S391 locus using PowerPlex Fusion in nine samples for allele 22, one sample for allele 25, and one sample for allele 26. However, these samples were typed as ordinary alleles within the bins using GlobalFiler. In this study, next-generation sequencing analysis using MiSeq was performed for the D12S391 locus from the 11 off-ladder samples and 33 other samples, as well as the allelic ladders of PowerPlex Fusion and GlobalFiler. All off-ladder allele 22 in the nine samples had [AGAT]11[AGAC]11 as a repeat structure, while the corresponding allele was [AGAT]15[AGAC]6[AGAT] for the PowerPlex Fusion ladder, and [AGAT]13[AGAC]9 for the GlobalFiler ladder. Overall, as the number of [AGAT] in the repeat structure decreased at the D12S391 locus, the peak migrated more slowly using PowerPlex Fusion, the reverse strand of which was labeled, and it migrated more rapidly using GlobalFiler, the forward strand of which was labeled. The allelic ladders of both STR kits were reamplified with our small amplicon D12S391 primers and their mobility was also examined. In conclusion, off-ladder observations of allele 22 at the D12S391 locus using PowerPlex Fusion were mainly attributed to a relatively large difference of the repeat structure between its allelic ladder and off-ladder allele 22.

Micro-pulverized extraction pretreatment for highly sensitive analysis of 11-nor-9-carboxy-Δ(9)-tetrahydrocannabinol in hair by liquid chromatography/tandem mass spectrometry

RATIONALE

A primary metabolite of Δ(9) -tetrahydrocannabinol, 11-nor-9-carboxytetrahydrocannabinol (THC-COOH), serves as an effective indicator for cannabis intake. According to the recommendations of the Society of Hair Testing, at least 0.2 pg/mg of THC-COOH (cut-off level) must be present in a hair sample to constitute a positive result in a drug test. Typically, hair is digested with an alkaline solution and is subjected to gas chromatography/tandem mass spectrometry (GC/MS/MS) with negative ion chemical ionization (NICI).

METHODS

It is difficult to quantify THC-COOH at the cut-off level using liquid chromatography/tandem mass spectrometry (LC/MS/MS) without acquisition of second-generation product ions in triple quadrupole-ion trap mass spectrometers, because large amounts of matrix components in the low-mass range produced by digestion interfere with the THC-COOH peak. Using the typical pretreatment method (alkaline dissolution) and micro-pulverized extraction (MPE) with a stainless bullet, we compared the quantification of THC-COOH using GC/MS/MS and LC/MS/MS.

RESULTS

MPE reduced the amount of matrix components in the low-mass range and enabled the quantification of THC-COOH at 0.2 pg/mg using a conventional triple quadrupole liquid chromatograph coupled to a mass spectrometer. On the other hand, the MPE pretreatment was unsuitable for GC/MS/MS, probably due to matrix components in the high-mass range. The proper combination of pretreatments and instrumental analyses was shown to be important for detecting trace amounts of THC-COOH in hair.

CONCLUSIONS

In MPE, samples can be prepared rapidly, and LC/MS/MS is readily available, unlike GC/MS/MS with NICI. The combination of MPE and LC/MS/MS might therefore be used in the initial screening for THC-COOH in hair prior to confirmatory analysis using GC/MS/MS with NICI.

Genotyping of Toxic Pufferfish Based on Specific PCR-RFLP Products As Determined by Liquid Chromatography/Quadrupole-Orbitrap Hybrid Mass Spectrometry

A method based on liquid chromatography-electrospray mass spectrometric analysis of the enzymatically digested amplicons derived from the mitochondrial 16S rRNA gene was established for the discrimination of toxic pufferfish. A MonoBis C18 narrow-bore silica monolith column (Kyoto Monotech) and a Q Exactive mass spectrometer (Thermo Fisher) were employed for separation and detection, respectively. Monoisotopic masses of the oligonucleotides were calculated using Protein Deconvolution 3.0 software (Thermo Fisher). Although a lock mass standard was not used, excellent accuracy (mass error, 0.83 ppm on average) and precision (relative standard deviation, 0.49 ppm on average) were achieved, and a mass accuracy of <2.8 ppm was maintained for at least 180 h without additional calibration. The present method was applied to 29 pufferfish samples, and results were consistent with Sanger sequencing.

Distribution measurement of amphetamine-type stimulants in organs using micropulverized extraction and liquid chromatography/tandem mass spectrometry to complement drug distribution using mass spectrometry imaging

Amphetamine-type stimulants (ATS) such as methamphetamine are widely abused and can cause toxic effects in the body. In this study, a simple and accurate analytical method for distribution measurement of drugs in organs was developed to visualize localization of ATS in organs and to complement drug distribution by mass spectrometry imaging (MSI). The brain, liver and kidney from rats to which ATS had been administered were segmented into blocks of 2×2×2 mm3 at -30°C. Each organ block was micropulverized with a stainless-steel bullet at -80°C. The concentrations of drugs in each block were measured by liquid chromatography/tandem mass spectrometry. The three-dimensional distribution of drugs in a whole organ was expressed using color gradation of drug concentration after reconstruction of all blocks to the original locations. The distribution was also compared with that obtained by MSI. This method enabled measurement of drug distribution in organs with simple and clean procedures and accurate quantification unlike autoradiography and MSI. The methamphetamine concentrations were different between parts in an organ, particularly in the kidney. This method could be applicable to the measurement of the distribution of compounds in various solid samples and could be used as a complementary method for the measurement of the distribution of compounds by MSI.