Development and validation of a gas chromatography–mass spectrometry assay for opiates and cocaine in human teeth

A multidisciplinary approach to forensic biological profiling on a single tooth and nail sample

INTRODUCTION

Analysis of a single tooth and nail can provide valuable forensic information, including year of birth, year of death, age, sex, DNA-profile, geographic residence during childhood and at time of death and drug exposure. The aim is to minimize the amount of used bodily material and to validate the applicability of a multidisciplinary sampling protocol.

METHODS

A nail of the big toe, a tooth and blood of seven deceased individuals were collected postmortem. Collected materials were sampled and segmented in accordance with the multidisciplinary sampling protocol. DNA analysis was conducted on the pulp of the tooth, isotope analysis (Sr, Pb, O and C) on the enamel and 14C-, toxicological and tooth cementum annulation analysis on root segments. DNA-, isotope (Sr, Pb, O and C) -, toxicological-, and 14C -analysis were conducted on toenail segments. The acquired DNA profiles were compared with profiles acquired from blood.

RESULTS

Material from seven deceased persons was analysed. 45 out of 56 analyses on dental samples were successful, constituting a success rate of 80%. Additionally, 27 out of 35 analyses were successful on nail samples, yielding a success rate of 77%. DNA-, toxicological and 14C- analyses performed better in nail than in tooth. Isotope analyses performed better in tooth than in nail. A profile with personal characteristics was constructed and matched for 62% of parameters with collected medical information.

CONCLUSION

The performed sampling protocol for simultaneous multidisciplinary forensic analysis on a single tooth and nail sample provided applicable results and valuable information.

Towards an integrative approach to the biological profile

One of the most important tasks in forensic anthropology is the construction of the biological profile, classically defined as a set of four basic biological descriptors: biological sex, age-at-death, ancestry, and stature. Yet, our empirical and technological abilities in reconstructing the life experiences and health from skeletal remains far exceed these four parameters and forensic anthropology could benefit from further descriptors in the search for an identity. In this paper, we propose the inclusion of two other investigations to forensic anthropology practice to implement the already known biological profile: the interpretation of bone disease and lesions, and forensic toxicology on unconventional biological matrices. These analyses can provide information regarding health, habits, and disease burden, and by implementing them in our practice of forensic anthropology, they have the potential to improve the biological profile. We also propose a new term that can include not only the classical biological profile but also further descriptors, namely, the "biocultural profile".

A pilot study on post-mortem determination of drug abuse on dental tissues

BACKGROUND

Post-mortem toxicology constantly deals with the research of reliable alternative matrices to be applied in case of highly damaged corpses (such us carbonized, skeletonized, human remains, etc.). Teeth represent a promising alternative matrix since dental tissues are endowed by different features, resistance and stability after death.

SCOPE

Since scant literature reported on the pharmacokinetics and mechanism of incorporation of xenobiotics into dental tissues, this pilot research aims to investigate whether in the pulp can be detected the same substances found in blood in drug related death cases. Secondly, the study is addressed to disclose the possible deposit of drugs in dental hard tissues (dentine and/or enamel), thus contributing to reconstruct the drug abuse history (timing, e.g.).

MATERIALS AND METHODS

The study experimented with a novel method to separately analyse dental enamel, dentin, and pulp, applied to 10 teeth collected during autopsies of drug-related deaths along with blood and hair samples for classic toxicological analyses. Each tooth was prepared by "pulverization technique" and then analysed by gas chromatography paired with mass spectrometry (GC-MS) and ultra high performance liquid chromatography coupled to high resolution mass spectrometry (UHPLC/HR-MS) for searching cocaine, opiates, and metabolites. The results were then compared with those obtained from blood and hair samples.

RESULTS

Preliminary results demonstrated that teeth differ from any other classic matrix (blood and hairs) since the qualitative correspondence of the detected substances between pulp and blood as well as dental hard tissues and hair suggests that they can be useful in post-mortem evaluation as a unique matrix for both acute and chronic assumptions of drugs. The mechanism of accumulation of substances in mineralized dental tissues emerged the most significant result, being influenced by the type of molecule and the method of assumption. The main limitation of this study is the limited availability of the sample and the absence of anamnestic information of the time, rates and method of drug assumption during life. Further research is necessary to systematically investigate the distribution of different substances within the different tissues of the tooth.

Drugs in dental biofilm and enamel - A pilot study

Objective

Enamel and dental biofilm might serve as alternative matrices for determination of illicit and medical drugs. Thus, this study aims at evaluating possible correlations between detected drug concentrations in the matrices and simulated drug use in situ.

Design

Eleven subjects wore intraoral splints with embedded demineralized bovine enamel samples. Drug use was simulated by mouth rinsing with a 1.0 μg/ml drug solution three times daily for 1 min (study A) or by incubation of the splints in a 10 μg/ml drug solution once a day for 30 min (study B). Amphetamines, opiates, cocaine and benzoylecgonine were used as drugs. After 11 days, biofilm and enamel samples of the intraoral splints were analyzed by liquid chromatography mass spectrometry after drying and extraction via ultrasonication with acetonitrile (biofilm) or methanol (enamel).

Results

In study A, median and mean drug concentration ± standard deviation were 1.3 pg/mg and 6.4 ± 11 pg/mg in biofilm and 0.2 pg/mg and 0.5 ± 0.9 pg/mg in enamel. In study B, median and mean drug concentration ± standard deviation were 350 pg/mg and 1100 ± 1600 pg/mg in biofilm and 5.8 pg/mg and 9.9 ± 10 pg/mg in enamel.

Conclusions

Overall, there were considerable interindividual concentration differences. Correlations between concentrations in the two sample materials were shown. The results of this pilot study revealed a dependence of concentrations on intensity and duration of drug contact. Thus, important information on past drug use might be provided in forensic cases by analysis of dental biofilm and enamel.

In vitro studies on the dependence of drug deposition in dentin on drug concentration, contact time, and the physicochemical properties of the drugs

The chemical analysis of dental hard tissues can provide information on previous drug use due to the deposition of drugs into this tissue. For the interpretation of analytical results in, e.g., postmortem toxicology or regarding archeological samples, the influence of drug dosing, consumption frequency, duration of intake and type of drug on analyte concentrations in teeth has to be characterized. To approximate these correlations, in vitro models were applied to investigate the time dependency of drug deposition via and against pulp pressure (perfusion studies) and the concentration dependency of drug deposition via oral cavity (incubation study) as well as the influence of de- and remineralization (pH cycling) on the incorporation of drugs in bovine dentin pellets. Some of the drugs of abuse most relevant in forensic case work (amphetamines, opiates, cocaine and benzoylecgonine) were applied. Concentrations in dentin samples were analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) after pulverization and extraction via ultrasonication with methanol. The studies showed that drug deposition in dentin likely depends on the physicochemical properties of the drug molecules as well as on the duration of contact with drugs via the blood stream and on drug concentrations present in the oral cavity. Higher drug concentrations in teeth can result from a more frequent or longer drug use. In addition, intake of higher doses or oral/inhalative consumption can also be expected to lead to higher drug concentrations. These findings can be helpful for the interpretation of postmortem cases.

Application of Teeth in Toxicological Analysis of Decomposed Cadavers Using a Carbamazepine-Administered Rat Model

In a regular autopsy, blood and organs are used to quantify drug and toxicant concentrations; however, specimens such as blood cannot be collected from highly decomposed corpses, making the quantification of drug and toxicants impossible. This study aimed to estimate the blood carbamazepine (CBZ) concentration from teeth, a part of the human body that is best preserved after death. We sampled teeth and blood of rats administered CBZ. The correlation between the tooth and serum CBZ concentrations was analyzed. Rats were euthanized after CBZ administration and kept at 22 °C for 0 to 15 days before sampling the teeth and measuring the CBZ concentration. Undecalcified, fresh, frozen sections of rat teeth were prepared, and CBZ localization was evaluated. CBZ concentrations in both teeth and cardiac blood peaked at 60 min after administration and increased in a dose-dependent manner. CBZ concentration in teeth did not substantially change after death, with high CBZ distribution being observed in the pulp cavity. The tooth and serum CBZ concentrations were highly correlated, suggesting that the measurement of toxicant concentration in sampled teeth would allow for the estimation of blood toxicant concentration in highly decomposed corpses.

Prenatal alcohol exposure can be determined from baby teeth: Proof of concept

BACKGROUND

Prenatal alcohol exposure (PAE), leading to fetal alcohol spectrum disorders (FASD), is a serious public health issue in the United States and globally. Diagnosis of FASD is crucial in obtaining appropriate care, but it is not always possible when PAE cannot be documented.

METHODS

Deciduous teeth from a child with known PAE and a child with known absence of PAE were analyzed using liquid chromatography-isotope dilution tandem mass spectrometry (LC-IDMS/MS) in a multiple-reaction monitoring mode for direct markers and LC-high resolution MS in positive and negative mode with hydrophilic interaction liquid chromatography and reverse-phase chromatography, respectively, for indirect markers.

RESULTS

Direct markers of PAE (ethyl glucuronide and ethyl sulfate) were detected in prenatal and postnatal dentine from a case tooth but not from a control tooth. Indirect biomarker analysis indicated a dysregulation of amino acids and an increase in cholesterol sulfate in the case compared to the control tooth.

CONCLUSIONS

This proof-of-concept study demonstrates for the first time that direct biomarkers of PAE are detectable and measurable in deciduous teeth which begin forming in utero and are typically naturally shed between 5 and 12 years of age. Further examination of these novel biomarkers may allow diagnosis of FASD where documentation of PAE is otherwise unavailable. Furthermore, because teeth grow incrementally, defined growth zones can be sampled allowing for identification of gestational timing of PAE to help better understand mechanisms underlying alcohol's disruption of perinatal development.

Tooth biomarkers to characterize the temporal dynamics of the fetal and early-life exposome

BACKGROUND

Teeth have unique histology that make this biomatrix a time-capsule for retrospective exposure analysis of fetal and early life. However, most analytic methods require pulverizing the whole tooth, which eliminates exposure timing information. Further, the range of chemicals and endogenous exposures that can be measured in teeth has yet to be fully characterized.

METHODS

We performed untargeted metabolomics on micro-dissected layers from naturally shed deciduous teeth. Using four liquid-chromatography high-resolution mass spectrometry analytical modes, we profiled small molecules (<1000 Da) from prenatal and postnatal tooth fractions. In addition, we employed linear regression on the tooth fraction pairs from 31 children to identify metabolites that discriminate between prenatal and postnatal exposures.

RESULTS

Of over 10,000 features measured in teeth dentin, 390 unique compounds were annotated from 62 chemical classes. The class with the largest number of compounds was carboxylic acids and their derivatives (36%). Of the annotated exogenous metabolites (phthalates, parabens, perfluoroalkyl compounds, and cotinine) and endogenous metabolites (fatty acids, steroids, carnitines, amino acids, and others), 91 are linked to 256 health conditions through published literature. Differential analysis revealed 267 metabolites significantly different between the prenatal and the postnatal tooth fractions (adj. p-value < 0.05, Bonferroni correction), and 21 metabolites exclusive to the prenatal fraction.

CONCLUSIONS

The prenatal and early postnatal exposome revealed from dental biomarkers represents a broad range of endogenous and exogenous metabolites for a comprehensive characterization in environmental health research. Most importantly, this technology provides a direct window into fetal exposures that is not possible by maternal biomarkers. Indeed, we identified several metabolites exclusively in the prenatal fraction, suggesting unique fetal exposures that are markedly different to postnatal exposures. Expansion of databases that include tooth matrix metabolites will strengthen biological interpretation and shed light on exposures during gestation and early life that may be causally linked with later health conditions.

The tooth exposome in children's health research

PURPOSE OF REVIEW

The exposome concept proposes a comprehensive assessment of environmental exposures from the prenatal period onwards. However, determining exposure timing, especially over the prenatal period, is a major challenge in environmental epidemiologic studies.

RECENT FINDINGS

For decades, teeth have been used to estimate long-term cumulative exposure to metals. Recently developed high-dimensional analytical methods, which combine sophisticated histological and chemical analysis to precisely sample tooth layers that correspond to specific life stages, have the potential to reconstruct the exposome in the second and third trimesters of prenatal development and during early childhood.

SUMMARY

A retrospective temporal exposomic approach that precisely measures exposure intensity 'and timing' during prenatal and early childhood development would substantially aid epidemiologic investigations, particularly case-control studies of rare health outcomes.

Tooth matrix analysis for biomonitoring of organic chemical exposure: Current status, challenges, and opportunities

Epidemiological evidence supports associations between prenatal exposure to environmental organic chemicals and childhood health impairments. Unlike the common choice of biological matrices such as urine and blood that can be limited by short half-lives for some chemicals, teeth provide a stable repository for chemicals with half-life in the order of decades. Given the potential of the tooth bio-matrix to study long-term exposures to environmental organic chemicals in human biomonitoring programs, it is important to be aware of possible pitfalls and potential opportunities to improve on the current analytical method for tooth organics analysis. We critically review previous results of studies of this topic. The major drawbacks and challenges in currently practiced concepts and analytical methods in utilizing tooth bio-matrix are (i) no consideration of external (from outer surface) or internal contamination (from micro-odontoblast processes), (ii) the misleading assumption that whole ground teeth represent prenatal exposures (latest formed dentine is lipid rich and therefore would absorb and accumulate more organic chemicals), (iii) reverse causality in exposure assessment due to whole ground teeth, and (iv) teeth are a precious bio-matrix and grinding them raises ethical concerns about appropriate use of a very limited resource in exposure biology and epidemiology studies. These can be overcome by addressing the important limitations and possible improvements with the analytical approach associated at each of the following steps: (i) tooth sample preparation to retain exposure timing, (ii) organics extraction and pre-concentration to detect ultra-trace levels of analytes, (iii) chromatography separation, (iv) mass spectrometric detection to detect multi-class organics simultaneously, and (v) method validation, especially to exclude chance findings. To highlight the proposed improvements we present findings from a pilot study that utilizes tooth matrix biomarkers to obtain trimester-specific exposure information for a range of organic chemicals.

Determination of drugs of abuse in bovine dentin using liquid chromatography-electrospray ionization tandem mass spectrometry

Drugs deposited in human teeth are well preserved; the spectrum of toxicological investigations may therefore be supplemented by an analysis method for drugs in teeth. A liquid chromatography-electrospray ionization tandem mass spectrometry assay for the detection and quantification of basic drugs of abuse in bovine dentin samples was developed and validated. The drugs and metabolites amphetamine, methamphetamine, methylenedioxymethylamphetamine, methylenedioxyethylamphetamine, codeine, morphine, cocaine and benzoylecgonine were extracted from 50 mg ground dentin powder by ultrasonication for 60 min in methanol 3 times. The extracts were analyzed on a triple-quadrupole mass-spectrometer in multiple reaction monitoring mode. The method was validated and proved to be accurate, precise, selective, specific and stable with good linearity within the calibration range and a lower limit of quantification of 10 to 20 pg/mg. To artificially load bovine dentin samples with drugs, the natural process of de- and remineralization in the oral cavity was mimicked by a pH-cycling experiment. The artificially drug-loaded dentin samples showed drug concentrations of 20 to 80 pg/mg. The method can be applied in further in vitro experiments as well as in post-mortem cases, especially where limited sample tissue is available.

Teeth as a biomarker of past chemical exposure

PURPOSE OF REVIEW

Accurate prenatal exposure assessment is one of the major challenges in environmental epidemiologic studies. Variations in placental transport make maternal biospecimens unreliable for many chemicals and fetal specimens collected at birth do not provide information on exposure timing over the prenatal period.

RECENT FINDINGS

The skeletal compartment is an important chemical repository, making calcified tissues important for measuring exposure. For decades teeth have been used to estimate long-term cumulative exposure to metals and some organic chemicals. Recently developed methodologies that combine sophisticated histological and chemical analysis to precisely sample tooth layers that correspond to specific life stages have the potential to reconstruct exposure in the second and third trimesters of prenatal development and during early childhood.

SUMMARY

Such a retrospective biomarker that precisely measures exposure intensity and timing during prenatal development would substantially aid epidemiologic investigations, particularly case-control studies of rare health outcomes.

Bioanalytical methods for the determination of cocaine and metabolites in human biological samples

Determination of cocaine and its metabolites in biological specimens is of great importance, not only in clinical and forensic toxicology, but also in workplace drug testing. These compounds are normally screened for using sensitive immunological methods. However, screening methods are unspecific and, therefore, the posterior confirmation of presumably positive samples by a specific technique is mandatory. Although GC-MS-based techniques are still the most commonly used for confirmation purposes of cocaine and its metabolites in biological specimens, the advent of LC-MS and LC-MS/MS has enabled the detection of even lower amounts of these drugs, which assumes particular importance when sample volume available is small, as frequently occurs with oral fluid. This paper will review recently-published papers that describe procedures for detection of cocaine and metabolites, not only in the most commonly used specimens, such as blood and urine, but also in other 'alternative' matrices (e.g., oral fluid and hair) with a special focus on sample preparation and chromatographic analysis.

Bioanalytical procedures and recent developments in the determination of opiates/opioids in human biological samples

The use and abuse of illegal drugs affects all modern societies, and therefore the assessment of drug exposure is an important task that needs to be accomplished. For this reason, the reliable determination of these drugs and their metabolites in biological specimens is an issue of utmost relevance for both clinical and forensic toxicology laboratories in their fields of expertise, including in utero drug exposure, driving under the influence of drugs and drug use in workplace scenarios. Most of the confirmatory analyses for abused drugs in biological samples are performed by gas chromatographic-mass spectrometric methods, but use of the more recent and sensitive liquid chromatography-(tandem) mass spectrometry technology is increasing dramatically. This article reviews recently published articles that describe procedures for the detection of opiates in the most commonly used human biological matrices, blood and urine, and also in unconventional ones, e.g. oral fluid, hair, and meconium. Special attention will be paid to sample preparation and chromatographic analysis.

On-site screening and GC-MS analysis of cocaine and heroin metabolites in body-packers urine

The illicit transportation of cocaine and heroin either swallowed or inserted into the rectum and/or vagina of individuals, defined as "body-packers", is becoming increasingly common. Assessment of smuggling by urinalysis from body-packers has been sparsely reported and on-site rapid screening methods are essentially lacking. We screened the presence of cocaine and heroin metabolites in urine from suspected body-packers by an on-site immunochromatographic test and confirmed the obtained results by gas chromatography-mass spectrometry and X-ray examination. Samples were collected from 64 individuals (45 men, 19 women) stopped at Fiumicino and Ciampino airports of Rome (Italy) for suspicion of internal concealment of cocaine and heroin between October 2006 and July 2007. Urine was immediately screened on-site by Cozart rapid urine test. Irrespective of test results, individuals underwent X-ray examination and urine samples were analyzed by gas chromatography-mass spectrometry (GC-MS). In 48 out of 64 cases (24 positives and 24 negatives) screening results were confirmed by GC-MS assay and X-ray examination. In 5 cases, positive to the on-site test and GC-MS analysis, abdominal radiography was negative and individuals resulted to be drug users. In 11 cases, negative to the on-site test and radiological investigation, GC-MS analysis found benzoylecgonine in 10 cases and morphine in one case. Concentration of both substances was in all cases lower than 50ng/ml and compatible with personal drug use. From obtained results, on-site detection of cocaine and heroin metabolites in the urine of suspected body-packers appears to be a reliable screening test to disclose internally concealed drugs and justify subsequent radiological investigations.

Morphine and its metabolites: Analytical methodologies for its determination

The present article reviews the methods of determination published for morphine and its metabolites covering the period from 1980 until at the first part of 2006. The overview includes the most relevant analytical determinations classified in the following two types: (1) non-chromatographic methods and (2) chromatographic methods.

Electrochemiluminescence determination of codeine or morphine with an organically modified silicate film immobilizing Ru(bpy)32+

An ECL approach was developed for the determination of codeine or morphine based on tris(2,2'-bipyridine)ruthenium(II) (Ru(bpy)(3)(2+)) immobilized in organically modified silicates (ORMOSILs). Tetramethoxysilane (TMOS) and dimethyldimethoxysilane (DiMe-DiMOS) were selected as co-precursors for ORMOSILs, which were then immobilized on a surface of glassy carbon electrode (GCE) by a dip-coating process. Ru(bpy)(3)(2+) was immobilized in the ORMOSIL film via ion-association with poly(p-styrenesulphonate). The ORMOSIL-modified GCE presented good electrochemical and photochemical activities. In a flow system, the eluted codeine or morphine was oxidized on the modified GCE and reacted with immobilized Ru(bpy)(3)(2+) at a potential of +1.20 V (vs. Ag/AgCl). The modified electrode was used for the ECL determination of codeine or morphine and showed high sensitivity. The calibration curves were linear in the range 2 x 10(-8)-5 x 10(-5) mol/L for codeine and 1 x 10(-7)-3 x 10(-4) mol/L for morphine. The detection limit was 5 x 10(-9) mol/L for codeine and 3 x 10(-8) mol/L for morphine, at signal:noise ratio (S:N)=3. Both codeine and morphine showed reproducibility with RSD values <2.5% at 1.0 x 10(-6) mol/L. Furthermore, the modified electrode immobilized Ru(bpy)(3)(2+) was applied to the ECL determination of codeine or morphine in incitant samples.