Comprehensive Evaluation of Cocaine and its Hydroxy Metabolites in Seized Cocaine and a Large Cohort of Hair Samples.

As cocaine is not only incorporated into hair via blood following ingestion but also by external contamination, hair samples are commonly tested for cocaine metabolites to prove ingestion. However, cocaine metabolites can also be present as degradation products in typical street cocaine samples. The present study investigates minor hydroxycocaine metabolites para- and meta-hydroxycocaine together with para- and meta-hydroxybenzoylecgonine in seized cocaine (n=200) and hair samples from routine casework (n=2,389). Analytical results of hair samples were interpreted using an established decision model for the differentiation between actual use and external contamination using metabolic ratios (metabolite to cocaine). They were further examined concerning background of request, hair color, body site of sample collection, sex, and metabolic ratios of the main metabolites (benzoylecgonine, norcocaine, and cocaethylene). All seized cocaine samples were positive for para- and meta-hydroxycocaine with a maximum percentage of 0.025 and 0.052 %, respectively; para- and meta-hydroxybenzoylecgonine were detected in 55 and 56 % of samples with a maximum percentage of 0.044 and 0.024 %, respectively. Analytical results of 424 hair samples (17.7 %) were interpreted as being predominantly from contamination; the majority of these samples were from traffic medicine cases (83.7 %). Metabolic ratios of minor hydroxycocaine metabolites were significantly higher in hair samples interpreted as originating from use than in samples interpreted as caused by contamination. Metabolic ratios for hydroxycocaines were significantly higher in forensic cases compared to abstinence controls and also in black hair compared to blond/gray hair. However, this was not the case for hydroxybenzoylecgonine metabolic ratios. No statistical difference was observed with regard to the donor's sex. Hydroxycocaine metabolic ratios increased significantly with increasing ratios of norcocaine and cocaethylene to cocaine, respectively. The study demonstrates that hydroxycocaine metabolites (including thresholds for their metabolic ratios) must be used for a reliable interpretation of positive cocaine results in hair samples.

Evaluating washing techniques to eliminate external contamination of trace elements in bat fur and bird feathers.

Non-invasive proxies, such as fur and feathers, are likely to be increasingly used to assess the potential exposure of chemicals, including trace metals and metalloids. However, the amount of external contamination is usually unknown, and there is no standard method for removing external contamination of trace metals in fur or feathers. To date, 40 % of studies published related to the measurement of trace metal levels in fur or the hair of non-human mammals and 24 % of studies in feathers do not state any washing methods or did not wash the samples before analysis. We assessed three washing techniques to remove external contamination of arsenic (As), lead (Pb), and zinc (Zn) from bat fur. We selected the three most frequently used fur washing methods from literature. To test these methods, fur samples from great flying foxes (Pteropus neohibernicus neohibernicus, n=15 individuals) from Papua New Guinea preserved over eight decades (AMNH, USA) were used. Percentages of trace metal removed are 87.19 % (SD= 12.28), 92.99 % (SD= 5.5) and 88.57 % (SD= 9.33) for As, 54.72 % (SD= 31.64), 55.89 % (SD= 37.87), and 53.93 % (SD= 41.28) for Pb, and 74.03 % (SD= 22.96), 22.93 % (SD= 73), and 24.95 % (SD= 49.5) for Zn using M2, M3, and M4, respectively. We also assessed four washing techniques to remove external contamination of arsenic (As), mercury (Hg), and zinc (Zn) from bird feathers. We identified the four most prevalent washing techniques in the literature used for feathers. We used feathers from the great horned owl (Bubo virginianus) and the great blue heron (Ardea herodias) to test these methods. Percentages of trace metal removed are 34.35 % (SD= 44.22), 69.22 % (SD= 36.5), 62.59 % (SD= 48.37), and 80.89 % (SD= 14.54) for As, 66.97 % (SD= 13.26), 29.4 % (SD= 67.06), 49.68 % (SD= 42.33), and 28.88 % (SD= 69) for Hg, and <0 % (SD= 80.1), 0 % (SD= 29.55), 11.23 % (SD= 47.73), and 57.09 % (SD= 21.2) for Zn using M2, M3, M4, and M5, respectively. This study shows the importance of washing fur and feather samples prior to trace metals analyses in ecotoxicology and biomonitoring studies.

The influence of cosmetic treatments in the uptake of in vitro cocaine contamination in hair.

Hair analysis is a powerful tool to assess drug use, yet the challenge of external contamination complicates its interpretation. Understanding the influence of cosmetic hair treatments is pivotal as their presence may affect this phenomenon. This study investigated the effects of four cosmetic treatments (bleach, henna, gel, and dry shampoo) on the external in vitro contamination of cocaine and its primary metabolite, benzoylecgonine (BE). Hair samples were divided into four groups: A-hair treated with cosmetics then contaminated; B-hair contaminated then subjected to cosmetic treatment; and C-hair solely contaminated (control group). Negative hair samples (n = 24) were immersed in a cocaine and BE aqueous solution of 1 µg/mL for 24 h. All hair samples were analyzed by a LC-MSMS procedure successfully validated according to ANSI/ASB Standard 036 guidelines (limit of quantification at 10 pg/mg). Henna in Group A (n = 13) resulted in the most substantial reduction for cocaine (92%), while bleach in Group B (n = 15) showed an 80% decrease. For BE, Group A henna (n = 13) exhibited a 50% reduction, and Group B bleach (n = 15) demonstrated a 71% decrease, all compared to Group C (n = 24). The study found no significant differences concerning hair color (black (n = 3), brown (n = 10), red (n = 5) and blond (n = 6)) or shape (straight (n = 6), wavy (n = 16), curly (n = 1), and coily (n = 1)). All analysis were performed in triplicate with variations below 20%. These findings emphasize that cosmetic treatments do affect cocaine/BE concentrations in hair when exposed to external contamination, highlighting the importance of considering an individual's cosmetic history prior to interpretation.

Decontamination protocols affect the internal microbiota of ticks.

Studies on the microbiota of ticks have promoted hypotheses about the combined effects of the bacterial community, its functional contributions to the tick's physiology or probable competition effects with some tick-borne pathogens. However, knowledge on the origin of the microbiota of newly hatched larvae is missing. This study aimed to elucidate the source(s) of the microbiota in unfed tick larvae, addressing the composition of the "core microbiota" and the best ways to decontaminate eggs for microbiota studies. We applied laboratory degree bleach washes and/or ultraviolet light treatments on engorged Rhipicephalus australis females and/or their eggs. No significant effects of these treatments on the reproductive parameters of females and the hatching rates of eggs were observed. However, the different treatments did show striking effects on the composition of the microbiota. The results indicated that bleach washes disrupted the internal tick microbiota in females, implying that bleach may have entered the tick and subsequently affected the microbiota. Furthermore, the analyses of results demonstrated that the ovary is a main source of tick microbiota, while the contribution of Gené's organ (a part of the female reproductive system that secretes a protective wax coat onto tick eggs) or the male's spermatophore requires further investigation. Further studies are needed to identify best practice protocols for the decontamination of ticks for microbiota studies.

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.

Identifying contamination versus ingestion in hair testing, with cocaine as example.

When developing a procedure to identify external contamination of hair as opposed to drug that is in hair from ingestion, there are components of the process that must be considered in the final method. A method that does not achieve the objective may be missing one or more of these elements: choice of solvent, a drug-binding agent, ratio of solvent to hair, temperature, time, intactness of the hair, and establishing, for the chosen method, a criterion based on the drug contents of the wash and hair that indicates the hair may be contaminated.

Biological Effects Associated with Internal and External Contamination of Diagnostic Nuclear Medicine Sources: An In vitro Study.

AIM: In a Nuclear Medicine department, the risk of external and internal contamination in radiation workers is much higher than in other medical radiation facilities. The risk associated with both types of contaminations should be quantified to estimate the radiation dose received by the personal. Here, we designed an in vitro model to see the impact of internal and external contamination of F-18 and Technetium-99 m (Tc-99 m) on DNA damages. METHODOLOGY: Chinese hamster lung fibroblast V79 was used for all of the experiments. Irradiation was performed internally and externally (scenarios activity is mixed with the cell line [Internal] and activity kept at 1 cm distance from cell line [external]) using two different diagnostic radioactive sources (Tc-99 m and F-18) of known quantity 37 MBq. Total cumulated activity (MBq-min) was calculated up to one half-life of sources for both internal and external setups. An alkaline single gel electrophoresis technique (comet assay) was used for DNA damage analysis. Olive tail moment (OTM) was used to characterize DNA damage. RESULTS: We have not observed any significant difference (P > 0.05) in OTM between internal and external irradiation for cumulated activity presented before one half-life of both diagnostic isotopes. However, a significant difference in OTM was noted between internal and external irradiation for cumulated activity presented at one half-life of radioactive sources (P < 0.05). DNA damage with internal exposure was found to be 17.28% higher for F-18 and 23% higher for Tc-99 m than external exposure at one half-life of radioactive sources. Overall, we noted greater DNA damage in F-18 as compared to Tc-99 m. CONCLUSIONS: Our in vitro study practically demonstrated that internal contamination is more hazardous than external exposure.

Bird feathers are potential biomonitors for airborne elemental carbon.

Birds can serve as effective biomonitors of air pollution, yet few studies have quantified external particulate matter accumulation on bird feathers. Biomonitoring of airborne elemental carbon (EC) is of critical significance because EC is a component of particulate matter with adverse effects on air quality and human health. To assess their effectiveness for use in EC monitoring, we compared EC accumulation on bird feathers at two sites that differed in vehicular traffic volume in an urban environment within the Dallas-Fort Worth Metropolitan Area, USA. Moulted flight feathers from domestic chickens were experimentally exposed to ambient EC pollution for 5 days in two urban microenvironments 1.5 km distant from each other that differed in traffic volume--adjacent to an interstate highway and a university campus bus stop. Feathers near the highway accumulated approximately eight times more EC (307 ± 34 µg m-2 day-1), on average, than feathers near the bus stop (40 ± 9 µg m-2 day-1). These findings indicate that EC accumulation on feathers varies over short distances within urban areas and that bird feathers potentially can be used for biomonitoring airborne EC.

Does dilute nitric acid improve the removal of exogenous heavy metals from feathers? A comparative study towards the optimization of the cleaning procedure of feather samples prior to metal analysis.

Feather analysis has been widely used as a biomonitoring tool to assess metal contamination in birds, as their sampling is a non-destructive and ethically preferable technique. However, for feathers to be useful as a biomonitor of heavy metals, exogenous contamination has to be efficiently removed. Although much effort has been put into this, no washing procedure has yet proven able to ensure the total removal of the surface-associated metals. The purpose of this study was to propose an efficient washing procedure of feather samples prior to metal analysis, on the basis of comparison of various washing schemes designed according to previous analytical trials, and of the verification of the efficacy of the optimal scheme in cleaning intentionally contaminated feathers. Our investigation showed that dilute nitric acid alone or in combination with a detergent (Extran) or acetone under mild agitation of the samples performed better that any other cleaning scheme applied. Thus, a multi-step procedure including the sequential use of all three reagents was tested against feather samples contaminated by adsorbed or particulate metal species. The procedure was able to completely eliminate the external metal loads in all cases except for the partial removal of severe contamination with adsorbed Cd.

Determination of ethyl glucuronide in human hair samples: Decontamination vs extraction.

Decontamination of samples prior to analysis is common practice and recommended for ethyl glucuronide (EtG) hair testing. The aim of this study was to evaluate the applied decontamination procedure during routine hair EtG analysis by monitoring the ethyl glucuronide concentrations in the washing solutions from a representative cohort of individual hair samples. Hair samples from 150 individuals were tested for hair EtG by a validated routine procedure (liquid chromatography/tandem mass spectrometry). A four-step decontamination procedure (ethanol, water, acetone, dichloromethane) was applied to all samples prior to analysis. Hair samples from 20 individuals were analyzed along with the complete set of individual washing solutions. Hair samples from an additional 130 individuals were analyzed along with the corresponding aqueous wash fraction only. No EtG was detected in the washing solutions from hair samples that tested negative for EtG (n = 42). Hair samples positive for ethyl glucuronide (n = 108) were found to liberate different amounts of EtG during decontamination: whereas no, or low portions of, EtG (< 10% of extracted hair EtG) were found in the corresponding washing solutions of the majority (n = 91) of individual samples, there was a minority of samples (n = 6) with more than half of the extracted hair EtG present in the decontamination solvent. No correlation of the decontaminated amount of EtG and the extracted hair EtG was observed. Further experimental studies are necessary to investigate if the observed easily removable fraction of EtG is associated with external contamination and if analysis of wash solutions could be helpful for identifying external contamination in hair testing for ethyl glucuronide.

External interference from ambient air pollution on using hair metal(loid)s for biomarker-based exposure assessment.

Hair metal(loid)s are often measured as biomarkers to evaluate population internal exposure, however, hair samples could be easily contaminated by ambient particulate matter (PM) pollution. Here, we evaluated the potential external interference from ambient PM pollution on using hair metal(loid)s for population biomarker-based exposure assessment. The raw hair samples were strictly washed and placed under various indoor and outdoor scenarios for ~6 months at sites with high PM pollution. The contaminated hair was then washed using the same method. A total of 33 hair elements were quantified by inductively coupled plasma-mass spectrometry. The surface residual PM on hair after washing was observed by scanning electron microscopy. In addition, we chose a practical exposure scenario including 77 housewives in Shanxi Province, China for validation. The results for the hair exposure experiment revealed that external contamination of some elements that had relatively high concentrations in hair was generally mild in both indoor and outdoor exposure scenarios (i.e., Zn, Mg, Se, Fe, Sr, Ti, Mn, Sn, Ge, U, Co, Mo, and As). A relatively higher external contamination of other elements (e.g., Al, Cr, Pb, Cd, Li, and most rare earth elements (REEs)) was observed, especially for those elements with relatively low hair concentrations (e.g., Cd, and REEs) in the outdoor environment. This finding was due mainly to some small ambient PM not being fully removed by the current washing strategy when the hair sample was heavily contaminated. However, results from practical exposure scenario of the housewives showed that there were overall no significant differences of hair metal(loid)s between the housewives using coal and clean energy for cooking. We concluded that the external interference on hair internal metal(loid) analysis could be negligible when hair was efficiently washed, especially for population with relatively longer indoor activities. It is therefore promising to use hair analysis for their population exposure assessment.

Dietary proxies (δ15N, δ13C) as signature of metals and arsenic exposure in birds from aquatic and terrestrial food chains.

In this study, exposure to arsenic (As), lead (Pb), cadmium (Cd), copper (Cu) and zinc (Zn) was investigated in the blood, pectoral muscles and tail feathers of two terrestrial (spotted owlet; Athena brama and bank myna; Acridotheres ginginianus) and two aquatic (cattle egret; Bubulcus ibis and pond heron; Ardeola grayii) bird species inhabiting Pakistan. Food chain specimens, as well as the dietary proxies δ15N and δ13C, were also analyzed to validate potential trophic and dietary transfers of metals and As in birds. Zn was found to be the most prevalent metal in the tissues of birds followed by Pb, As, Cu, and Cd. The bioaccumulation of metals and As was higher in tail feathers reflecting the combined effect of both endogenous and exogenous contamination. Pectoral muscle and blood harbored lower levels of As and metals, indicating less recent exposure through diet. Aquatic birds feeding at higher trophic levels accumulated significantly higher concentrations of metals and As in their tissues (P < 0.05) and, therefore, may be at a greater risk of metal and As toxicity than terrestrial birds. Linear regression model depicts δ15N as a strong predictor of metals and As levels in the tissues of both aquatic and terrestrial birds, followed by the δ13C dietary proxy. All metals in aquatic species, except for Cd, as well as terrestrial species, except for Cu, exhibit bioaccumulative potential through the food chain (Trophic transfer factor: TTFs > 1) indicating potential harmful consequences for birds. Elevated concentrations of metals and As in tissues may cause harmful effects in birds potentially leading to declines in their populations.

Hair testing for cortisol by UPLC-MS/MS in a family: External cross-contamination from use of cortisol cream.

In the present study, an ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed, validated, and applied for measuring cortisol in human hair. Baseline levels of cortisol in hair were taken from 12 control subjects, with concentrations for adult controls (n = 8) of 1.7 to 9.1 pg/mg and a median of 4.7 pg/mg and for child controls (n = 4) of 1.1 to 7.2 pg/mg and a median of 3.1 pg/mg. However, the concentrations in the hair of two children whose mother had been applying a cortisol-containing hand cream 2-3 times per week ranged from 30 to 390 pg/mg. No external contamination was observed with the children as judged from wash water concentrations. The mother had hair cortisol concentrations of 80-220 pg/mg. External contamination was observed in her proximal hair segments (0-4 cm) but not in distal ones (8-12 cm). In an experiment, cortisol cream (1%) was applied on the fingers of a subject, who then scratched the head hair once in a while. Hair was collected 1, 5, and 30 days after exposure to the cream. The cortisol level in the hair one day after exposure was 20-186 times higher than the pre-exposure level. High levels in the wash fraction agreed with external contamination. Cortisol concentrations in the hair at 5 and 30 days after exposure were 15-38 and 9-11 times higher, respectively, than the pre-exposure levels. However, no external contamination was suggested from the wash water concentrations in the hair collected 5 and 30 days after exposure. The results showed that the externally applied cortisol had, after some time, been incorporated into the hair matrix and was not removed by a pre-analysis washing. Therefore, the use of a standard decontamination procedure prior to analysis of hair may not be able to prevent the spread of cortisol from applied hand cream within a family.

Influence of the external and internal radioactive contamination of the body and the clothes on the results of the thyroidal 131I measurements conducted in Belarus after the Chernobyl accident-Part 2: Monte Carlo simulation of response of detectors near the thyroid.

This paper describes the calculation of the response of the most common types of radiation detectors that were used within the first few weeks after the Chernobyl accident to determine the activity of 131I in the thyroids of Belarusian subjects of an epidemiologic study of thyroid cancer. The radiation detectors, which were placed against the necks of the subjects, measured the exposure rates due to the emission of gamma rays resulting from the radioactive decay of 131I in their thyroids. Because of the external and internal radioactive contamination of the monitored subjects, gamma radiation from many radionuclides in various locations contributed to the exposure rates recorded by the detectors. To estimate accurately the contribution from gamma rays emitted from various internal and external parts of the body, the calibration factors of the radiation detectors, expressed in kBq per µR h- 1, were calculated, by means of Monte Carlo simulation, for external irradiation from unit activities of 17 radionuclides located on 19 parts of the body, as well as for internal irradiation from the same 17 radionuclides in the lungs, from caesium radionuclides distributed uniformly in the whole body, and from 131I in the thyroid. The calculations were performed for six body sizes, representative of the age range of the subjects. In a companion paper, the levels of external and internal contamination of the body were estimated for a variety of exposure conditions. The results presented in the two papers were combined to calculate the 131I activities in the thyroids of all 11,732 Belarusian study subjects of an epidemiologic study of thyroid cancer and, in turn, their thyroid doses.

Hair analysis when external contamination is in question: A review of practical approach for the interpretation of results.

Despite having been extensively discussed over the last decade, the differentiation between systemic exposure and external contamination still continues to be one of the limitations of hair testing for drugs. For this reason, we consider it worthwhile to re-state some basic principles in this short review. Various studies investigating a diversity of wash protocols, most using artificially contaminated hair with cocaine, have been valuable in evaluating wash efficacy and in understanding the incorporation of drugs in hair. However, assessments of wash efficacy made with real hair samples, as opposed to artificially contaminated samples, provide a different perspective, and demonstrate how rarely external contamination affects the interpretation of results. Data from a large number of hair samples from crack cocaine users, confirmed the usefulness of our protocol to remove most of the externally deposited cocaine. The data showed that hair levels of cocaine and benzoylecgonine in crack cocaine users were overall high with ratio of benzoylecgonine to cocaine in all samples above 0.1. The wash residue concentrations of cocaine ranged from not detected to 21ng/mg with a median of 0.5ng/mg. Cocaine was detected in the wash residue in 105 out of 138 samples. The wash to hair cocaine ratio ranged from not detected to 0.36 with a median of 0.02. The wash to hair cocaine ratios were below 0.07 in 133 cases. The five cases that produced wash to hair ratios above 0.1, one sample was at 0.11, three at 0.13 and one at 0.36, possibly because these cases were at the lower end of cocaine levels, however, we could not rule out that the hair was contaminated. Whilst it is not possible to differentiate between the drug extracted from the hair and the drug attached to the outside of the hair, we can compare levels of drug in the wash residue with levels detected in the hair sample. In addition, further diagnostic criteria must be applied to minimise potential misdiagnosis of external contamination. When drugs are detected in hair, individuals have clearly been in an environment where drugs are present, but it is only on rare occasions that it is unclear whether this is the result of drug use or of external contamination, and, in those cases, the results of testing need to be interpreted in the light of corroborating evidence from clinical data or social context.

Interest of Single Hair Analysis to Document Drug Exposure: Literature Review and a Case Report Involving Zuclopenthixol.

The analysis of hair to detect drugs and drugs of abuse is performed in various contexts, including child protection cases, abstinence control programs, and workplace drug testing. This alternative matrix offers several advantages, such as a large detection window (months) and non-invasive collection. Segmental analysis of multiple hair strands for drugs and metabolites has been widely reported in the literature over the past three decades, whereas a review of the literature showed that there are only 26 articles that report the analysis of a single hair. They focus on two approaches: mass spectrometry imaging techniques, which improve the resolution of dating an intoxication or conventional methods, such as gas chromatography mass spectrometry and liquid chromatography tandem mass spectrometry (LC-MS/MS). Improved sensitivity of LC-MS/MS techniques allows the evaluation of drug content in segments of a single hair. However, the units used to express the results vary, and depend on the authors. Following a review of the literature, we present a case that illustrates drug analyses both in a strand of hair and a single hair. In this case of exposure of a child to zuclopenthixol (ZPT), the analysis of ZPT in a single segmented hair by LC-MS/MS strengthened the presumption of a single administration.

Hair analysis for opiates: hydromorphone and hydrocodone as indicators of heroin use.

BACKGROUND: Identification of external contamination is a challenge in hair analysis. This study investigates metabolite ratios of hydromorphone to morphine and hydrocodone to codeine as indicators to distinguish contamination from heroin use provided that hydromorphone/hydrocodone intake is excluded. RESULTS: Hair samples after external contamination with street heroin proved to be negative for hydromorphone/hydrocodone. Hair samples from individuals with suspected street heroin use/contamination or opiate medication were analyzed for 6-monoacetylmorphine, morphine, acetylcodeine, codeine, hydromorphone and hydrocodone, and metabolite ratios of hydromorphone to morphine and hydrocodone to codeine were assessed. Hair samples from individuals with medicinal heroin/morphine/codeine use displayed significantly higher metabolite ratios than those with suspected street heroin use/contamination. CONCLUSION: Hydromorphone/hydrocodone are solely formed during body passage. Thus, metabolite ratios can be used to distinguish morphine/heroin use from external contamination.

Metabolites of synthetic cannabinoids in hair--proof of consumption or false friends for interpretation?

The detection of drug metabolites in hair is widely accepted as a proof for systemic uptake of the drug, unless the metabolites can be formed as artefacts. However, regarding synthetic cannabinoids, not much is known about mechanisms of incorporation into hair. For a correct interpretation concerning hair findings of these compounds and their metabolites, it is necessary to identify the different routes of incorporation and to assess their contribution to analytical findings. This study presents the results of the LC-ESI-MS/MS analysis of an authentic hair sample taken from a patient with a known history of heavy consumption of synthetic cannabinoids. In the authentic hair sample, 5F-PB-22 and AB-CHMINACA as well as their main metabolites 5F-PB-22 3-carboxyindole, PB-22 5-OH-pentyl, and AB-CHMINACA valine were detected in all segments, comprising segments grown in a time period where the substances had not been distributed on the 'legal high' market. To enable interpretation of the results regarding the distribution of the detected analytes along the hair shaft, the stability of 5F-PB-22 and AB-CHMINACA in hair matrix and under thermal stress was assessed. The stability tests revealed that the three 'metabolites' are also formed in externally contaminated hair after storage of the samples under different conditions. In addition, 5F-PB-22 3-carboxyindole and AB-CHMINACA valine were identified as degradation products in smoke condensate. Therefore, interpretation of 'metabolite' findings of compounds comprising chemically labile amide/ester bonds or 5-fluoro-pentyl side chains should be carried out with utmost care, taking into account the different mechanisms of formation and incorporation into hair.

Evidence based decontamination protocols for the removal of external Δ9-tetrahydrocannabinol (THC) from contaminated hair.

External contamination can cause false positive results in forensic hair testing for drugs of abuse and is therefore a major concern when hair evidence is used in court. Current literature about decontamination strategies is mainly focused on external cocaine contamination and no consensus on the best decontamination procedure for hair samples containing cannabinoids has been reached so far. In this study, different protocols with solvents, both organic as well as aqueous, were tested on blank and drug user hair for their performance on removing external cannabis contamination originating from either smoke or indirect contact with cannabis plant material. Smoke contamination was mimicked by exposing hair samples to smoke from a cannabis cigarette and indirect contact contamination by handling hair with cannabis contaminated gloves or hands. Δ9-tetrahydrocannabinol (THC) levels in the hair samples and wash solvents were determined using liquid chromatography tandem mass spectrometry (LC-MS/MS) analysis. Aqueous surfactant solutions removed more THC contamination compared to water, but much less than organic solvents. Methanol, dichloromethane and chloroform were most efficient in removing THC contamination. Due to its lower environmental impact, methanol was chosen as the preferred decontamination solvent. After testing of different sequential wash steps on externally contaminated blank hair, three protocols performed equally well, removing all normal level and more than 99% of unrealistically high levels of external cannabis contamination. Thorough testing on cannabis users' hair, both as such and after deliberate contamination, showed that using these protocols all contamination could be washed from the hair while no incorporated THC was removed from truly positive samples. The present study provides detailed scientific evidence in support of the recommendations of the Society of Hair Testing: a protocol using a single methanol wash followed by a single aqueous SDS solution wash, followed by a Milli-Q water rinsing step, is suggested as the preferred decontamination protocol to remove external cannabis contamination from hair while preserving the incorporated compounds.

Potential external contamination of pneumatic seed drills during sowing of dressed maize seeds.

BACKGROUND: The use of pneumatic drills in maize cultivation causes dispersion in the atmosphere of some harmful substances normally used for dressing maize seeds. Some of the dust particles may be deposited on the machine's body, becoming dangerous for the environment and for operators. The aim of the present study was to analyse the amount of dust deposited on the frame of drills during maize sowing operations. Tests were performed with different drills and in different operating conditions. RESULTS: Data analysis showed that a significant amount (up to 30%) of the tracer can be deposited on the drill body. When wind was not present, higher quantities of tracer were collected and the forward speed did not influence significantly the tracer deposit on the seed drills. The use of different devices designed to prevent dust dispersion was able to limit up to 95% but was not able to eliminate the external contamination of the drill. CONCLUSION: The particles present on drills could become a problem for the operator during the filling of the drill. Additionally, the environment can be contaminated if pesticide remains on the drill, generating point-source pollution when the drill is parked outside. © 2015 Society of Chemical Industry.