Hair Analysis: Contamination versus Incorporation from the Circulatory System-Investigations on Single Hair Samples Using Time-of-Flight Secondary Ion Mass Spectrometry and Matrix-Assisted Laser Desorption/Ionization Mass Spectrometry

Application of Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) in forensic science - A review

The paper presents the possibilities of using the ToF-SIMS technique in the examination of a range of samples as forensic evidence. These include the analysis of documents, the examination of writing media, the analysis of crossing lines, the analysis of cosmetics, hair analysis, the examination of automobile paints, and the analysis of fingerprints and their contamination with exogenous substances. The advantages and disadvantages of this method were analysed with reference to the information that any forensic investigator would wish to obtain when examining highly significant evidence.

Decontamination promotes the release of incorporated organic contaminants in hair: Novel insights into non-invasive biomonitoring

Human hair is increasingly employed as a non-invasive biomonitoring matrix for exposure to organic contaminants (OCs). Decontamination procedures are generally needed to remove external contamination from hair prior to analysis of OCs. Despite various existing decontamination protocols, their impacts on internally incorporated (endogenous) OCs in hair remain poorly understood. This study aims to quantitatively assess the impact of decontamination procedures on endogenous OCs in hair, and investigate optimal decontamination processes and factors influencing the removal of endogenous OCs. In this study, guinea pig was exposed to 6 OCs (triphenyl phosphate (TPHP), tris(1,3-dichloro-2-propyl) phosphate (TDCPP), and tri-n-butyl phosphate (TNBP), bisphenol A (BPA), perfluorooctanoic acid (PFOA), and phenanthrene (PHE)), and 6 decontamination procedures with different solvents (methanol, n-hexane, acetone, ultrapure water, Triton X-100, and sodium dodecyl sulfate) were used to rinse exposed guinea pig hair. All OCs and three metabolites (diphenyl phosphate (DPHP), dibutyl phosphate (DBP), and bis(1,3-dichloro-2-propyl) phosphate (BDCPP)) were detected in the majority of washing solutions. The decontamination procedures apparently resulted in the release of endogenous OCs from hair. The percentages of residual OCs in hair exhibited a linear or exponential decrease with more washing cycles. Furthermore, the residuals of OCs in hair washed with organic and aqueous solvents showed negative correlations with molecular weight, polarizability, and their initial concentrations. Although these findings need to be validated with a broader range of OCs, the results obtained in this study provide compelling evidence that current hair decontamination procedures have significant impacts on the analysis of endogenous OCs in hair. Therefore, it is important to interpret quantitative data on hair OC concentrations with caution and to thoroughly consider each decontamination procedure during analysis.

Greener and whiter analytical method development and validation for determining the presence of zolpidem tartrate infused in apple juice using RP-HPLC via magnetic solid-phase extraction followed by LC-MS confirmatory analysis

The research work entails a newly developed RP-HPLC method, aimed at analyzing the modern date rape drug, zolpidem tartrate (ZT), infused in apple juice matrix. The work relies on dispersive solid-phase extraction (DSPE) with polyethylene imine (PEI)-coated magnetic nanoparticles to preconcentrate zolpidem from the matrix, in the presence of trifluoroacetic acid (TFA) for matrix isolation, for the first time. The optimized conditions emphasize the use of an environmentally preferable mobile phase [methanol: 0.5% acetic acid (60 : 40% v/v; pH 2.50)] at a 1 ml min-1 flow rate, employed with a Platisil Octa-Decyl Silane (ODS) column (250 × 4.6 mm; 5 μm). Further, the validated results were confirmed to be within the ICH guidelines, marking the method demonstrated to be linear (R 2 = 0.9988; 0.9957), robust (% RSD below 1), sensitive (LOD = 1.8 μg ml; LOQ = 6 μg ml-1), precise and accurate (% recovery = 92-120%). Following the same conditions, a confirmatory analysis of zolpidem was accomplished using LC-MS, verifying the method's suitability notably, with good peak resolution, less matrix interference and a confirmation of the presence of zolpidem using mass spectrometry. The recycling ability of the PEI@SiO2@Fe3O4 nanoparticles was also assessed. To determine the sustainability of the proposed work, a greener and whiter assessment has been carried out in a comparative mode with previous similar works. For green tools, the recently developed AGREE software was utilized for assessing the method's greeness and it demonstrated a good green score of 0.68, supported by method assessment using ComplexGAPI software. For the assessment of the method's blue principles, the latest software utilizing the blue applicability grade index (BAGI) was applied, resulting in a decent score of 62.5. To consider sustainability, the RGB methodical software in its latest version the RGBfast model, was incorporated in the study for furnishing a balance of the three different major principles (Red-Green-Blue) and for assessing a check on sustainability of the current method compared to similar previously established proposed works.

Electromembrane extraction of drugs of abuse and prescription drugs from micropulverized hair

Hair analysis can provide chronological insights into past drug use for months to years after drug administration. In comparison to analyses from other biological matrices, such as blood and urine, sample pretreatment is often tedious and not environmental friendly. In this study, we present a more environmental friendly approach to hair analysis using micropulverized hair and electromembrane extraction for the efficient extraction of 15 drugs of abuse, prescription drugs, and metabolites from hair. The optimized extraction method, involving micropulverization, demonstrated comparable yields to the standard approach of cutting and overnight incubation. A 15-min extraction method using a commercial electromembrane extraction prototype was developed and validated according to forensic guidelines, using only 10 µL of organic solvent per sample. The final method, employing HPLC-MS-MS with a biphenyl column, exhibited good linearity, precision, and sensitivity. An AgreePrep assessment comparing the environmental impact of our method with the standard routine method, involving overnight incubation and conventional liquid-liquid extraction, was conducted. This is the first time micropulverized hair has been subjected to electromembrane extraction.

Brief history of the alcohol biomarkers CDT, EtG, EtS, 5-HTOL, and PEth

This article traces the historical development of various biomarkers of acute and/or chronic alcohol consumption. Much of the research in this domain of clinical and laboratory medicine arose from clinics and laboratories in Sweden, as exemplified by carbohydrate deficient transferrin (CDT) and phosphatidylethanol (PEth). Extensive studies of other alcohol biomarkers, such as ethyl glucuronide (EtG), ethyl sulfate (EtS), and 5-hydroxytryptophol (5-HTOL), also derive from Sweden. The most obvious test of recent drinking is identification of ethanol in a sample of the person's blood, breath, or urine. However, because of continuous metabolism in the liver, ethanol is eliminated from the blood at a rate of 0.15 g/L/h (range 0.1-0.3 g/L/h), so obtaining positive results is not always possible. The widow of detection is increased by analysis of ethanol's non-oxidative metabolites (EtG and EtS), which are more slowly eliminated from the bloodstream. Likewise, an elevated ratio of serotonin metabolites in urine (5-HTOL/5-HIAA) can help to disclose recent drinking after ethanol is no longer measurable in body fluids. A highly specific biomarker of hazardous drinking is CDT, a serum glycoprotein (transferrin), with a deficiency in its N-linked glycosylation. Another widely acclaimed biomarker is PEth, an abnormal phospholipid synthesized in cell membranes when people drink excessively, having a long elimination half-life (median ~6 days) during abstinence. Research on the subject of alcohol biomarkers has increased appreciably and is now an important area of drug testing and analysis.

How to sample a seizure plant: the role of the visualization spatial distribution analysis of Lophophora williamsii as an example

Natural compounds in plants are often unevenly distributed, and determining the best sampling locations to obtain the most representative results is technically challenging. Matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI-MSI) can provide the basis for formulating sampling guideline. For a succulent plant sample, ensuring the authenticity and in situ nature of the spatial distribution analysis results during MSI analysis also needs to be thoroughly considered. In this study, we developed a well-established and reliable MALDI-MSI method based on preservation methods, slice conditions, auxiliary matrices, and MALDI parameters to detect and visualize the spatial distribution of mescaline in situ in Lophophora williamsii. The MALDI-MSI results were validated using liquid chromatography-tandem mass spectrometry. Low-temperature storage at -80°C and drying of "bookmarks" were the appropriate storage methods for succulent plant samples and their flower samples, and cutting into 40 μm thick sections at -20°C using gelatin as the embedding medium is the appropriate sectioning method. The use of DCTB (trans-2-[3-(4-tert-butylphenyl)-2-methyl-2-propenylidene]malononitrile) as an auxiliary matrix and a laser intensity of 45 are favourable MALDI parameter conditions for mescaline analysis. The region of interest semi-quantitative analysis revealed that mescaline is concentrated in the epidermal tissues of L. williamsii as well as in the meristematic tissues of the crown. The study findings not only help to provide a basis for determining the best sampling locations for mescaline in L. williamsii, but they also provide a reference for the optimization of storage and preparation conditions for raw plant organs before MALDI detection.

Key Points

An accurate in situ MSI method for fresh water-rich succulent plants was obtained based on multi-parameter comparative experiments.Spatial imaging analysis of mescaline in Lophophora williamsii was performed using the above method.Based on the above results and previous results, a sampling proposal for forensic medicine practice is tentatively proposed.

Performance of Hair Testing for Cocaine Use-Comparison of Five Laboratories Using Blind Reference Specimens

The purpose of this study was to compare results from five commercial hair testing laboratories conducting workplace drug testing with regard to bias, precision, selectivity and decontamination efficiency. Nine blind hair specimens, including cocaine-positive drug user specimens (some contaminated with methamphetamine) and negative specimens contaminated with cocaine, were submitted in up to five replicates to five different laboratories. All laboratories correctly identified cocaine in all specimens from drug users. For an undamaged hair specimen from a cocaine user, within-laboratory Coefficients of Variation (CVs) of 5-22% (median 8%) were reported, showing that it is possible to produce a homogenous proficiency testing sample from drug user hair. Larger CVs were reported for specimens composed of blended hair (up to 29%) and curly/damaged hair (19-67%). Quantitative results appeared to be method-dependent, and the reported cocaine concentrations varied up to 5-fold between the laboratories, making interlaboratory comparisons difficult. All laboratories reported at least one positive result in specimens contaminated with cocaine powder, followed by sweat and shampoo treatments. Benzoylecgonine, norcocaine, cocaethylene and hydroxylated cocaine metabolites were all detected in cocaine powder-contaminated specimens. This indicates that current industry standards for analyzing and reporting positive cocaine results are not completely effective at identifying external contamination. Metabolite ratios between meta- or para-hydroxy-cocaine and cocaine were 6- and 10-fold lower in contaminated specimens compared to those observed in cocaine user specimens, supporting their potential use in distinguishing samples positive due to contamination and drug use.

Morphological and chemical profiling for forensic hair examination: A review of quantitative methods

Within the past two decades, there have been many studies for quantitative analysis on human hair samples. Microscopical and chemical analysis techniques have been used to analyze various aspects of hair regarding biological, chemical, anthropological, cosmetic, and forensic applications. Studies have attempted to develop quantification methods to increase the evidentiary value of hair in forensic casework. The literature reviewed in this paper provides some of the current techniques used for forensic examinations and quantitative methods. Although microscopical analysis has been scrutinized in the past, using chemical and microscopical techniques can provide a myriad of information. The extraction of DNA from hair provides high-value evidence; however, it may not be readily available and may yield inconclusive results. Hair analysis can be used for many forensic applications such as comparison, toxicology, and exposure analysis. In this article, we will review published research material regarding chemical and microscopical techniques for human hair analysis. Aspects considered for this review were the sample size requirement for analysis and the destructive nature of the instrumental method. This review will focus on both macro and micro quantitative methods for human hair analysis.

Surface Analysis Techniques in Forensic Science: Successes, Challenges, and Opportunities for Operational Deployment

Surface analysis techniques have rapidly evolved in the last decade. Some of these are already routinely used in forensics, such as for the detection of gunshot residue or for glass analysis. Some surface analysis approaches are attractive for their portability to the crime scene. Others can be very helpful in forensic laboratories owing to their high spatial resolution, analyte coverage, speed, and specificity. Despite this, many proposed applications of the techniques have not yet led to operational deployment. Here, we explore the application of these techniques to the most important traces commonly found in forensic casework. We highlight where there is potential to add value and outline the progress that is needed to achieve operational deployment. We consider within the scope of this review surface mass spectrometry, surface spectroscopy, and surface X-ray spectrometry. We show how these tools show great promise for the analysis of fingerprints, hair, drugs, explosives, and microtraces.

Determination of contamination levels for multiple endocrine disruptors in hair from a non-occupationally exposed population living in Liege (Belgium)

Today, the interest in hair as alternative matrix for human biomonitoring of environmental pollutants has increased, but available data on chemical levels in hair remain scarce. In this study, the measurement of 2 bisphenols (A and S), 3 parabens (methyl-, ethyl- and propylparabens) and 8 perfluroralkyl compounds (PFCs) namely perfluoroctanesulfonate (PFOS), perfluorohexanesulfonate (PFHxS), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluroroheptanoic acid (PFHpA), perfluoropentanoic acid (PFPeA) and perfluorohexanoic acid (PFHxA) was carried out, using a thoroughly validated UPLC-MS/MS method, in the hair from 114 adults living in Liege (Belgium) and surrounding areas. The most frequently quantified compounds in the population were: bisphenol S (97.4%, median = 31.9 pg·mg-1), methylparaben (94.7%, median = 28.9 pg·mg-1), bisphenol A (93.9%, median = 46.6 pg·mg-1), ethylparaben (66.7%, median = 5.2 pg·mg-1), propylparaben (54.8%, median = 16.4 pg·mg-1) and PFOA (46.4%, median < 0.2 pg·mg-1). The other PFCs were detected only in few samples although current exposure of the Belgian population to PFCs was previously demonstrated using blood analyses. Nonparametric statistical analyses were performed to evaluate the influence of gender, hair treatments and hair length, but no significant difference was observed. Only age was positively correlated with the propylparaben contamination. Although blood seems to remain more suitable for PFCs exposure assessment, the results of this study suggest that hair can be an appropriate matrix for biomonitoring of organic pollutants such as parabens or bisphenols.

Molecular imaging of humain hair with MeV-SIMS: A case study of cocaine detection and distribution in the hair of a cocaine user

Human hair absorbs numerous biomolecules from the body during its growth. This can act as a fingerprint to determine substance intake of an individual, which can be useful in forensic studies. The cocaine concentration profile along the growth axis of hair indicates the time evolution of the metabolic incorporation of cocaine usage. It could be either assessed by chemical extraction and further analysis of hair bundels, or by direct single hair fibre analysis with mass spectroscopy imaging (MSI). Within this work, we analyzed the cocaine distribution in individual hair samples using MeV-SIMS. Unlike conventional surface analysis methods, we demonstrate high yields of nonfragmented molecular ions from the surface of biological materials, resulting in high chemical sensitivity and non-destructive characterisation. Hair samples were prepared by longitudinally cutting along the axis of growth, leaving half-cylindrical shape to access the interior structure of the hair by the probing ion beam, and attached to the silicon wafer. A focused 5.8 MeV 35Cl6+ beam was scanned across the intact, chemically pristine hair structure. A non-fragmented protonated [M+ H]+ cocaine molecular peak at m/z = 304 was detected and localized along the cross-section of the hair. Its intensity exhibits strong fluctuations along the direction of the hair’s growth, with pronounced peaks as narrow as 50 micrometres, corresponding to a metabolic incorporation time of approx. three hours.

Evaluation of decontamination procedures for drug testing in undamaged vs damaged hair

INTRODUCTION

Although substances incorporated by ingestion are strongly bound to hair, their loss may occur if aggressive decontamination procedures are applied, especially in highly damaged/porous hair.

AIMS

Evaluation of cleaning procedures using hair samples with different porosity obtained from ethanol or drug users (cocaine, heroin, methamphetamine, methadone, fentanyl, tramadol, diazepam, buprenorphine, dihydrocodeine, citalopram and trazodone). The effect of washing time and multiple wash steps with water and methanol were evaluated.

METHODS

Hair samples (n=16) were selected and evaluated according to: a) the drug pattern consumption, b) available amount, and c) hair porosity (c1 'cosmetic treatment', c2: storage time). Six of them were soaked with an aqueous deuterated analogue solution. The samples were cut in 1 cm segments and homogenized. All hair samples were then decontaminated one or six times with 1.5 mL of water or methanol during 1, 5, 15, 30, 60 and/or 90 min (n=1 to 3/sample, depending on the available amount of hair). Hair extracts were then cleaned up via an SPE or LLE extraction, while the washes were evaporated to dryness. All were thereafter reconstituted and analysed with routine UPLC-MS/MS methods.

RESULTS AND DISCUSSION

Although concentrations of parent drugs and/or metabolites presented a negative trend along the washing time with methanol (up to 80%), the compounds were relatively well retained in hair even after a 90 min wash in most samples. Their retention would depend mostly on the hair nature rather than their physicochemical properties (whether incorporated by ingestion and/or from external contamination). Moreover, parent drugs and/or metabolites were detected in the washes in most samples, and the ratio between hair and washes decreased along the washing time. More than 50% of the deuterated analogues soaked into hair were still present after the different washing steps.

CONCLUSION

Generally, the substances analysed were well retained in hair samples after different washing steps with water or methanol. Losses were observed more frequently for long term stored hair samples, after decontamination with methanol for more than 30 min. Therefore, prolonged or repeated cleaning with methanol should be avoided in general procedures.

Cell and Tissue Imaging by TOF-SIMS and MALDI-TOF: An Overview for Biological and Pharmaceutical Analysis

The potential of mass spectrometry imaging (MSI) has been demonstrated in cell and tissue research since 1970. MSI can reveal the spatial distribution of a wide range of atomic and molecular ions detected from biological sample surfaces, it is a powerful and valuable technique used to monitor and detect diverse chemical and biological compounds, such as drugs, lipids, proteins, and DNA. MSI techniques, notably matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) and time of flight secondary ion mass spectrometry (TOF-SIMS), witnessed a dramatic upsurge in studying and investigating biological samples especially, cells and tissue sections. This advancement is attributed to the submicron lateral resolution, the high sensitivity, the good precision, and the accurate chemical specificity, which make these techniques suitable for decoding and understanding complex mechanisms of certain diseases, as well as monitoring the spatial distribution of specific elements, and compounds. While the application of both techniques for the analysis of cells and tissues is thoroughly discussed, a briefing of MALDI-TOF and TOF-SIMS basis and the adequate sampling before analysis are briefly covered. The importance of MALDI-TOF and TOF-SIMS as diagnostic tools and robust analytical techniques in the medicinal, pharmaceutical, and toxicology fields is highlighted through representative published studies.

Mapping the Chemistry of Hair Strands by Mass Spectrometry Imaging-A Review

Hair can record chemical information reflecting our living conditions, and, therefore, strands of hair have become a potent analytical target within the biological and forensic sciences. While early efforts focused on analyzing complete hair strands in bulk, high spatial resolution mass spectrometry imaging (MSI) has recently come to the forefront of chemical hair-strand analysis. MSI techniques offer a localized analysis, requiring fewer de-contamination procedures per default and making it possible to map the distribution of analytes on and within individual hair strands. Applying the techniques to hair samples has proven particularly useful in investigations quantifying the exposure to, and uptake of, toxins or drugs. Overall, MSI, combined with optimized sample preparation protocols, has improved precision and accuracy for identifying several elemental and molecular species in single strands of hair. Here, we review different sample preparation protocols and use cases with a view to make the methodology more accessible to researchers outside of the field of forensic science. We conclude that—although some challenges remain, including contamination issues and matrix effects—MSI offers unique opportunities for obtaining highly resolved spatial information of several compounds simultaneously across hair surfaces.

Development of a Standardized Microflow LC Gradient to Enable Sensitive and Long-Term Detection of Synthetic Anabolic-Androgenic Steroids for High-Throughput Doping Controls

Synthetic androgenic anabolic steroids (AAS) are banned compounds and considered as major threats by both racing and sports international authorities. Hence, doping control laboratories are continually looking into analytical improvements to increase their detection capabilities, notably by means of emerging technologies. To enhance analytical performances for the detection of synthetic AAS such as stanozolol, specific chromatographic procedures have been developed using recent quaternary liquid chromatography technology originally designed for high-throughput standardized proteomics connected to mass spectrometry. Applying the newly designed elution procedures described in this paper to the analyses of stanozolol and its metabolites in complex matrixes revealed improved sensitivity compared to previously described high-throughput methods. Indeed, we report the consistent and reliable detection of 16β-hydroxy-stanozolol down to 10 pg/mL in equine urine and being detectable up-to 3 months after a microdosing administration. Furthermore, a five months long elimination of stanozolol and its metabolites could be monitored on horse mane sections after a single dose administration. Our work highlights novel solutions to detect AAS with improved sensitivity. The application of such developments constitutes new landmarks for doping control laboratories and could be extended to other targeted compounds in residue analysis, toxicology, and metabolomics. Based on this work, the developed chromatographic method is now freely available within the Evosep Plus program.

History of hair analysis by mass spectrometry imaging

In conventional forensic science, blood and urine have been used for drug testing. However, hair has recently attracted attention as a new source of biological information in this milieu. Drugs and biomolecules taken up by the hair from the capillaries of the scalp are retained in the hair without being degraded by enzymes, migrating toward the tip of the hair as the hair grows at a constant rate. As a result, drug residues are stored in the hair in chronological order. In recent years, mass spectrometry imaging (MSI) has been developed to visualize the history of drug use in hair samples, making use of this unique property. Advances in this drug testing technique are expected to create a powerful deterrent for drug abuse and doping. In this paper, we introduce the history of hair research using MSI and the evolution of instruments, matrices, and methods.

Significance of Metabolite Ratios in the Interpretation of Segmental Hair Testing Results-Differentiation of Single from Chronic Morphine Use in a Case Series

In morphine intoxication cases, forensic toxicologists are frequently confronted with the question of if the individual was opioid-tolerant or opioid-naïve, which can be investigated by hair analysis. However, interpretation of results can be challenging. Here, we report on hair testing for morphine and its metabolite hydromorphone following morphine intoxication without tolerance and upon chronic use. Two consecutive hair samples were collected after a non-fatal intoxication. Analysis comprised short hair segments and their initial wash water solutions. In the intoxications, morphine and hydromorphone levels were 3.3 to 56 pg/mg and at maximum 9.8 pg/mg, respectively. Both levels and hydromorphone to morphine ratios were significantly lower compared to chronic morphine use. In the non-fatal intoxication, the highest hydromorphone to morphine ratio was obtained in the segment corresponding to the time of intoxication. Morphine ratios of wash to hair were significantly higher in the intoxications compared to chronic use, being indicative of sweat/sebum contamination. We recommend including the analysis of hydromorphone and the initial wash solution in cases of morphine intoxications. Our study demonstrates that hydromorphone to morphine ratios can help in distinguishing single from chronic morphine use and in estimating the period of exposure when a consecutive hair sample can be collected in survived intoxications.

A Comprehensive Multi-Analyte Method for Hair Analysis: Substance-Specific Quantification Ranges and Tool for Task-Oriented Data Evaluation

The aim of the present study was to quantify a large number of analytes including opioids, stimulants, benzodiazepines, z-drugs, antidepressants and neuroleptics within a single sample workup followed by a single analytical measurement. Expected drug concentrations in hair are strongly substance dependent. Therefore, three different calibration ranges were implemented: 0.5 to 600 pg/mg (group 1), 10 to 12,000 pg/mg (group 2) and 50 to 60,000 pg/mg (group 3). In order to avoid saturation effects, different strategies were applied for selected transitions including the use of parent mass ions containing one or two 13C-isotopes and detuning of the declustering potential and/or collision energy. Drugs were extracted from pulverized hair by a two-step extraction protocol and measured by liquid chromatrography--tandem mass spectrometry (LC--MS-MS) using Scheduled MRM™ Algorithm Pro. In total, 275 MRM transitions including 43 deuterated standards were measured. The method has been fully validated according to international guidelines. A MultiQuant™ software based tool for task-oriented data evaluation was established, which allows extracting selected information from the measured data sets. The matrix effects and recoveries were within the allowed ranges for the majority of the analytes. The lower limits of quantification (LLOQs) were for ∼72% of the analytes in the low-pg/mg range (0.5-5 pg/mg) and for ∼24% of the analytes between 10 and 50 pg/mg. These LLOQs considered cut-offs by the Society of Hair Testing (SoHT), if recommended. The herein established multi-analyte approach meets the specific requirements of forensic hair testing and can be used for the rapid and robust measurement of a wide range of psychoactive substances. The analyte-specific wide concentration ranges open up a wide field of applications.

Insights into the Decontamination of Cocaine-Positive Hair Samples

A highly discussed step in hair sample preparation for forensic analytics is the applied decontamination. The here presented investigations aim to gain insight and give recommendations on how to conduct this decontamination for the analysis of cocaine consumption in hair. Key insights were gained from the investigation of cocaine consumer hair, which was artificially contaminated in a humid atmosphere with ¹³C₆ labelled cocaine and from cocaine powder contaminated hair. Several decontamination protocols were investigated, whereby the usage of a decontamination protocol consisting of multiple short repetitive washes allowed to visualize the wash out of (¹³C₆-) cocaine. Multiple methanol washes proved to be an efficient and simple decontamination approach. Our findings showed that decontamination protocols can successfully wash out recent cocaine contaminations. They were observed to be rather quickly washed out, whereas cocaine from consumption or “older” cocaine contaminations were shown to eliminate both at a constant rate (from inner hair compartments). Thus, the usage of decontamination protocols to differentiate between consumption and contamination was shown to be limited. As contamination can happen any time at any level, only the application of elaborated decision trees, based on cocaine metabolite ratios and thresholds, can provide the distinction between consumption and contamination. Thus, the authors highly recommend the usage of such tools on all hair samples analyzed for cocaine consumption.

LC-MS/MS method for determining picogram-level of zolpidem and its main metabolites in hair using a zirconia-based sorbent

Although urine and blood samples have been conventionally used for testing zolpidem (ZPD), a sedative-hypnotic, these matrices have limited application because they have a relatively short detection period and can be used only in case of recent drug exposure. Therefore, it is necessary to use an alternative biological sample to obtain the evidence of ZPD misuse. Herein, a liquid chromatography-tandem mass spectrometric (LC-MS/MS) method was developed for the determination of ZPD and its metabolites, zolpidem phenyl-4-carboxylic acid (ZPCA) and zolpidem 6-carboxylic acid (ZCA), in hair to resolve the above-mentioned problems. Mechanical pulverization of hair, methanol extraction with sonication, and the zirconia-based hybrid solid-phase extraction technique were used for obtaining improved extraction efficiency and effective sample purification. The treated hair sample was analyzed using the LC-MS/MS method with the electrospray ionization source in positive and multiple-reaction monitoring modes. The target analytes were separated and detected within 8 min using an Xselect HSS T3 column. Gradient elution was performed using 5 mM ammonium formate and acetonitrile. The lower limit of quantification of ZPD, ZPCA, and ZCA were 1.0, 0.5, and 1.0 pg mg^-1, respectively. The calibration ranges were 1.0-1000.0 pg mg^-1 for ZPD, 0.5-200.0 pg mg^-1 for ZPCA, and 1.0-200.0 pg mg^-1 for ZCA, with the determination coefficients (r² ≥ 0.9986). The intraday accuracy and precision ranged from -7.1 to 9.0% and within 6.5%, respectively, and the interday accuracy and precision ranged from -6.1 to 7.9% and within 5.4%, respectively. The recovery, matrix effect, and process efficiency were 65.2-96.6%, 64.6-106.5%, and 44.3-100.5%, respectively, with the relative standard deviation of 4.0-5.0%. The developed method was successfully applied to analyze 13 forensic hair samples of ZPD abusers, and the concentration ratios of ZPD and its two main metabolites (ZPCA and ZCA) in the ZPD-positive samples were also presented. These results revealed that ZPCA and ZCA were not easily incorporated into hair, and demonstrated that their analysis in hair samples requires the employed method to have picogram-level sensitivity. Therefore, the developed method was suitable for simultaneous analysis of ZPD, ZPCA, and ZCA in hair samples, and it could provide clear evidence for illegal ZPD administration, including ZPD-facilitated sexual assault.

Determination of zolpidem phenyl-4-carboxylic acid and zolpidem 6-carboxylic acid in hair using gas chromatography-electron ionization-tandem mass spectrometry

A gas chromatography-electron ionization-tandem mass spectrometric (GC-EI-MS/MS) method was developed and validated for determination of the major metabolites of zolpidem, zolpidem phenyl-4-carboxylic acid (ZPCA) and zolpidem 6-carboxylic acid (ZCA) in human hair. The sample preparation procedure involves decontamination, mechanical pulverization, incubation, extraction and purification prior to instrumental analysis. The extracts were derivatized using hexafluoroisopropanol and heptafluorobutyric anhydride and analyzed by GC-EI-MS/MS. The linear ranges were 8-100 pg/mg for ZPCA and 16-200 pg/mg for ZCA, with the correlation coefficients >0.997. The limits of detection were 1.8 pg/mg for ZPCA and 1.7 pg/mg for ZCA. The recoveries ranged from 77.6 to 111.7%. The intra- and inter-day precisions were within 16.9 and 11.7%, while intra- and inter-day accuracies were -7.0-8.7 and -2.8-7.8%, respectively. The developed method was applied for the analysis of forensic hair samples obtained from suspected zolpidem abusers and the following concentration ranges were monitored: ZPCA 11.9-35.9 pg/mg and ZCA 16.6-21.8 pg/mg. The method proved to be suitable for picogram-level determination of ZPCA and ZCA in human hair.

Multimodal Imaging Mass Spectrometry: Next Generation Molecular Mapping in Biology and Medicine

Imaging mass spectrometry has become a mature molecular mapping technology that is used for molecular discovery in many medical and biological systems. While powerful by itself, imaging mass spectrometry can be complemented by the addition of other orthogonal, chemically informative imaging technologies to maximize the information gained from a single experiment and enable deeper understanding of biological processes. Within this review, we describe MALDI, SIMS, and DESI imaging mass spectrometric technologies and how these have been integrated with other analytical modalities such as microscopy, transcriptomics, spectroscopy, and electrochemistry in a field termed multimodal imaging. We explore the future of this field and discuss forthcoming developments that will bring new insights to help unravel the molecular complexities of biological systems, from single cells to functional tissue structures and organs.

Using time-of-flight secondary ion mass spectrometry (ToF-SIMS) and matrix assisted laser desorption/ionization mass spectrometry (MALDI-MS) for investigations on single hair samples to solve the contamination versus incorporation issue of hair analysis in the case of cocaine and methadone

Drug testing in hair is a controversial subject of discussion. Claims that decontamination protocols could generate false-positive samples, by washing contamination in hair, have unsettled many toxicologists. At least for zolpidem (known for showing only minor contamination), it could be shown that differentiation of the drug incorporated via the bloodstream from contamination was possible. The current work addresses cocaine and methadone, known for their high concentrations and contamination issues. Longitudinally and cross-sectioned samples of drug-soaked hair, consumer hair and cocaine powder contaminated hair were investigated using time of flight-secondary ion mass spectrometry (ToF-SIMS) and matrix-assisted laser desorption/ionization-mass spectrometry (MALDI-MS). In addition, the resulting wash solutions were investigated using LC-MS/MS. Differentiation of contamination from incorporation was possible for soaked and consumer hair samples. Therefore, contamination could be localized in the superficial compartments of hair and could be removed using strong wash protocols. In the case of powder contaminated hair samples, a small amount of cocaine remained in the inner structures even after the application of the strongest wash protocols. However, taking into consideration the differences in their behavior during decontamination steps compared to both soaked and authentic hair samples, the validity of this contamination protocol (rubbing cocaine powder into hair) must be questioned. Furthermore, when using cut-off values and metabolite ratios (from routine hair analysis), the differentiation of incorporation from contamination was possible also for all our experimental samples in this study. Inclusion of metabolites and application of cut-off values are therefore a must in routine hair analysis.