ABSTRACT
Street cocaine is often mixed with various substances that intensify its harmful effects. This paper proposes a framework to identify attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) intervals that best predict the concentration of adulterants in cocaine samples. Wavelengths are ranked according to their relevance through ReliefF and mRMR feature selection approaches, and an iterative process removes less relevant wavelengths based on the ranking suggested by each approach. Gaussian Process (GP) regression models are constructed after each wavelength removal and the prediction performance is evaluated using RMSE. The subset balancing a low RMSE value and a small percentage of retained wavelengths is chosen. The proposed framework was validated using a dataset consisting of 345 samples of cocaine with different amounts of levamisole, caffeine, phenacetin, and lidocaine. Averaged over the four adulterants, the GP regression coupled with the mRMR retained 1.07â¯% of the 662 original wavelengths, outperforming PLS and SVR regarding prediction performance.
Subject(s)
Cocaine , Drug Contamination , Cocaine/analysis , Drug Contamination/prevention & control , Spectroscopy, Fourier Transform Infrared/methods , Normal Distribution , Caffeine/analysis , Levamisole/analysis , Phenacetin/analysis , Regression AnalysisABSTRACT
Toxic adulterants are drug or chemical agents used to add bulk volume to traditional drugs of abuse such as cocaine and heroin. These cutting agents include levamisole, metamizole, noxiptillin, phenacetin and xylazine as well as common legal drugs such as acetaminophen, caffeine, diphenhydramine, lidocaine, quinine, quetiapine and tramadol. Because they possess pharmacological activity they result in exposure of the user, but also in the case of pregnant women, the developing fetus, to potential drug toxicity. We describe the development, validation and implementation of a rapid (48 second sample-to-sample) test based on a qualitative data-dependent liquid chromatography-quadrupole time of flight mass spectrometry method for the analysis of toxic adulterating substances in umbilical cord tissue (UCT) samples. The method provides a means of studying potential in utero exposure to these agents. Library spectra comparison at three different collision energies was used in conjunction with retention time and accurate mass to identify these substances in UCT. Analytically based reporting limits were established to determine positivity rates of adulterants in UCT utilizing a standard addition approach. The method was applied to authentic cocaine and opioid positive UCT to screen for toxic adulterants. There were a total of 82 potential adulterant positives found in a 30-sample cohort of authentic UCT samples, with an average of 2.7 substances per case. Lidocaine was the predominant finding followed by caffeine, and diphenhydramine all of which could result from non-illicit drug exposure, however, there were positives for levamisole, phenacetin, noxiptillin and xylazine none of which are approved in the United States for human therapeutic use. This initial set of data established a preliminary positivity rate of potentially toxic adulterants in UCT samples positive for cocaine or opioid use.
Subject(s)
Cocaine , Levamisole , Analgesics, Opioid , Caffeine/analysis , Cocaine/analysis , Diphenhydramine , Drug Contamination , Female , Humans , Lidocaine/analysis , Phenacetin/analysis , Pregnancy , Umbilical Cord , XylazineABSTRACT
Cocaine is a naturally occurring psychostimulant drug available worldwide. Drug trafficking networks adulterate pure cocaine with cutting agents to increase their earnings. This study presents a descriptive statistical analysis of the cutting agents found in 2118 cocaine samples that were seized in the Northern Region of Colombia (in the period 2015-2017). The data used in this study was drawn from the GC-MS analytical reports of the National Institute of Legal Medicine and Forensic Sciences -Colombia, Northern Region. Results showed diverse cutting agents in seized cocaine samples, from which the most commonly used are caffeine, phenacetin, lidocaine, imidazole and levamisole. In addition, cocaine samples showed different mixtures of the above cutting agents, predominantly caffeine/phenacetin and caffeine/lidocaine/phenacetin mixtures.
Subject(s)
Cocaine/chemistry , Drug Contamination , Drug Trafficking/trends , Aporphines/analysis , Caffeine/analysis , Codeine/analysis , Colombia , Humans , Imidazoles/analysis , Levamisole/analysis , Lidocaine/analysis , Phenacetin/analysis , Spatio-Temporal Analysis , Tetramisole/analysisABSTRACT
Microcompartments in the form of water-in-oil droplets have been utilized to construct artificial cells and simulate human body environment. However, the performance of subcellular structure involved metabolism in emulsion droplets has not been explored, and the underlying mechanism is still being elucidated. In this work, drug metabolism is presented on the basis of great amounts of microcompartments formed of picoliter-volume droplets with different radius (R), using a commercial four-way valve as a droplet generator. A model substrate, phenacetin, and its metabolite, paracetamol, are quantitatively analyzed by liquid-chromatography (LC) tandem mass spectrometry (MS/MS), and the reaction kinetics is characterized. In microdroplets of varying size (R = 18, 27, 42, and 51 µm, respectively), both conversion ratio and reaction rate constant of the metabolism are influenced in different degree. For instance, the substrate conversion ratio after 60 min of incubation in R = 27 µm droplets improves from 15% to 42%, and the reaction rate constant improves nearly five-fold, compared to that in bulk phase. The influence of microcompartment size on metabolism rate is further explored by simulation using a diffusion-reaction model. The droplet-based strategy is rapid, accurate and cost-efficient, fitting especially into biomimetic metabolism studies.
Subject(s)
Acetaminophen/analysis , Biomimetic Materials/analysis , Biomimetic Materials/metabolism , Microspheres , Phenacetin/analysis , Phenacetin/metabolism , Chromatography, High Pressure Liquid , Diffusion , Emulsions/chemistry , Kinetics , Metabolome , Models, Chemical , Oils/chemistry , Tandem Mass Spectrometry , Water/chemistryABSTRACT
OBJECTIVES: Drug checking is a harm reduction intervention that allows for identification of drug composition. The objective of the study was to assess drug market components and concordance between expected substance reported by clients and results from point-of-care drug checking at music festivals and events in British Columbia. METHODS: From July to September 2018, we provided drug checking services at four events using combination Fourier Transform Infrared (FTIR) spectroscopy and fentanyl immunoassay strips. We measured concordance between expected substance as reported by clients to the results from the FTIR/fentanyl immunoassay strip and tracked unexpected adulterants. RESULTS: In total, 336 checks were completed. Most samples were expected by clients to be psychedelics (69.3%) or stimulants (19.6%). Of the 233 psychedelic samples, 169 (72.5%) contained the expected, unadulterated substance, and 27 (11.6%) contained additional contaminants. Of 66 stimulant samples, 41 (62.1%) contained expected substance, while 24 (36.4%) contained additional contaminants. Unexpected adulterants such as fentanyl, levamisole, and phenacetin were also found, in addition to several novel psychoactive substances. DISCUSSION: We found a large proportion of substances that contained unexpected adulterants. Our findings highlight the value of continued drug checking and will be helpful in designing future harm reduction interventions in similar contexts.
Subject(s)
Drug Contamination/statistics & numerical data , Illicit Drugs/analysis , Immunoassay/statistics & numerical data , Spectroscopy, Fourier Transform Infrared/statistics & numerical data , Substance Abuse Detection/statistics & numerical data , British Columbia/epidemiology , Central Nervous System Stimulants/analysis , Fentanyl/analysis , Hallucinogens/analysis , Harm Reduction , Holidays , Humans , Immunoassay/methods , Levamisole/analysis , Music , Phenacetin/analysis , Reproducibility of Results , Substance Abuse Detection/methodsABSTRACT
INTRODUCTION: Brazil is the world's biggest consumer of crack cocaine, and dependence is a major public health issue. This is the first study to investigate the prevalence of potentially harmful adulterants present in hair samples from Brazilian patients with crack cocaine dependence. METHOD: We evaluated adulterants in hair samples extracted by convenience from 100 patients admitted at the 48 hour-observation unit of Centro de Referência de Álcool, Tabaco e Outras Drogas (CRATOD), Brazil's largest center for addiction treatment. A cross-sectional analysis was performed with the data obtained. RESULTS: Adulterants were found in 97% of the analyzed hair samples. The most prevalent adulterant was lidocaine (92%), followed by phenacetin (69%) and levamisole (31%). CONCLUSION: Adulterants were widely prevalent in hair samples from crack users treated at CRATOD: at least one adulterant was present in virtually all the hair samples collected. This points to a need to monitor adverse effects in the clinical setting in order to provide this high-risk group of patients with prompt and effective care related to the acute and chronic complications associated with these adulterants.
Subject(s)
Cocaine-Related Disorders , Crack Cocaine/analysis , Drug Contamination , Hair/chemistry , Levamisole/analysis , Lidocaine/analysis , Phenacetin/analysis , Adolescent , Adult , Brazil , Female , Humans , Male , Young AdultABSTRACT
Abstract Introduction Brazil is the world's biggest consumer of crack cocaine, and dependence is a major public health issue. This is the first study to investigate the prevalence of potentially harmful adulterants present in hair samples from Brazilian patients with crack cocaine dependence. Method We evaluated adulterants in hair samples extracted by convenience from 100 patients admitted at the 48 hour-observation unit of Centro de Referência de Álcool, Tabaco e Outras Drogas (CRATOD), Brazil's largest center for addiction treatment. A cross-sectional analysis was performed with the data obtained. Results Adulterants were found in 97% of the analyzed hair samples. The most prevalent adulterant was lidocaine (92%), followed by phenacetin (69%) and levamisole (31%). Conclusion Adulterants were widely prevalent in hair samples from crack users treated at CRATOD: at least one adulterant was present in virtually all the hair samples collected. This points to a need to monitor adverse effects in the clinical setting in order to provide this high-risk group of patients with prompt and effective care related to the acute and chronic complications associated with these adulterants.
Resumo Introdução O Brasil é o maior consumidor mundial de crack, e a dependência é um grande problema de saúde pública. Este é o primeiro estudo a investigar a prevalência de adulterantes potencialmente nocivos presentes em amostras de cabelo de pacientes brasileiros com dependência de crack. Métodos Foram avaliados adulterantes em amostras de cabelos extraídos por conveniência de 100 pacientes internados na unidade de observação de 48 horas do Centro de Referência de Álcool, Tabaco e Outras Drogas (CRATOD), o maior centro de tratamento de dependência do Brasil. Uma análise transversal foi realizada com os dados obtidos. Resultados Foram encontrados adulterantes em 97% das amostras de cabelo analisadas. O adulterante mais prevalente foi a lidocaína (92%), seguida da fenacetina (69%) e levamisol (31%). Conclusão Os adulterantes foram amplamente prevalentes em amostras de cabelo de usuários de crack tratados no CRATOD: pelo menos um adulterante estava presente em praticamente todas as amostras de cabelo coletadas. Isso aponta para a necessidade de monitorar os efeitos adversos no ambiente clínico, a fim de proporcionar a esse grupo de pacientes de alto risco cuidados imediatos e efetivos relacionados às complicações agudas e crônicas associadas a esses adulterantes.
Subject(s)
Humans , Male , Female , Adolescent , Adult , Young Adult , Phenacetin/analysis , Levamisole/analysis , Drug Contamination , Crack Cocaine/analysis , Cocaine-Related Disorders , Hair/chemistry , Lidocaine/analysis , BrazilABSTRACT
Cocaine was the second most widely used drug in Europe in 2016, with 3.5 million consumers aged 15-64 years old. Adulterants are pharmacologically active substances developed for medical purposes, however, there is little knowledge about their influence in the human body when there is concomitant use with cocaine. The objective of this work was to validate a method that allows the identification, confirmation and quantification of cocaine adulterants in blood samples collected in vivo or post-mortem. The studied substances were atropine, phenacetin, hydroxyzine, ketamine, lidocaine and tetramisole. A retrospective study of the prevalence of these substances, as well as their relative concentrations, was made analysing 97 real blood samples previously tested positive for cocaine and/or its metabolites. The analytes of interest were extracted, using a simple method based on protein precipitation with frozen acetonitrile and further analysis by GC/MS. The method was fully validated in accordance with parameters and criteria implemented in the lab and SWGTOX recommendations (mean recovery: 94-115%; CV: 6.2-13%; BIAS: 2.7-7.8%). 31 samples were positive for adulterants: phenacetin (19%), tetramisole (15%), lidocaine (8%) and hydroxyzine (1%). Concentrations were higher in post-mortem samples for all compounds analysed. Lidocaine was more prevalent in samples collected in vivo whereas tetramisole was present almost exclusively in post-mortem samples. Phenacetin was evenly distributed between post-mortem and in vivo samples. The validated method allows rapid, precise, accurate and economic analysis of selected compounds and requires smaller sample aliquots which can be important in post-mortem cases. The information collected can be important in future studies of correlation between the presence of adulterants and cocaine toxicity.
Subject(s)
Cocaine/chemistry , Drug Contamination , Narcotics/chemistry , Atropine/analysis , Forensic Toxicology/methods , Gas Chromatography-Mass Spectrometry , Humans , Hydroxyzine/analysis , Ketamine/analysis , Lidocaine/analysis , Phenacetin/analysis , Tetramisole/analysisABSTRACT
Adulteration is a common practice in the illicit drugs market, but the psychoactive and toxic effects provided by adulterants are clinically underestimated. Coca-paste (CP) is a smokable form of cocaine which has an extremely high abuse liability. CP seized samples are sold adulterated; however, qualitative and quantitative data of CP adulteration in forensic literature is still scarce. Besides, it is unknown if adulterants remain stable when CP is heated. This study was designed to report the chemical content of an extensive series of CP seized samples and to demonstrate the stability (i.e., chemical integrity) of the adulterants heated. To achieve this goal, the following strategies were applied: (1) a CP adulterated sample was heated and its fume was chemically analyzed; (2) the vapor of isolated adulterants were analyzed after heating; (3) plasma levels of animals exposed to CP and adulterants were measured. Ninety percent of CP seized samples were adulterated. Adulteration was dominated by phenacetin and caffeine and much less by other compounds (i.e., aminopyrine, levamisole, benzocaine). In the majority of CP analyzed samples, both cocaine and caffeine content was 30%, phenacetin 20% and the combination of these three components reached 90%. Typical cocaine pyrolysis compounds (i.e., BA, CMCHTs, and AEME) were observed in the volatilized cocaine and CP sample but no pyrolysis compounds were found after isolated adulterants heating. Cocaine, phenacetin, and caffeine were detected in plasma. We provide current forensic data about CP seized samples and demonstrated the chemical integrity of their adulterants heated.
Subject(s)
Anesthetics, Local/analysis , Anesthetics, Local/chemistry , Coca/chemistry , Cocaine/analysis , Cocaine/chemistry , Illicit Drugs/analysis , Animals , Caffeine/analysis , Caffeine/chemistry , Chromatography, High Pressure Liquid , Coca/metabolism , Cocaine/blood , Drug Contamination , Gas Chromatography-Mass Spectrometry , Illicit Drugs/blood , Illicit Drugs/chemistry , Male , Phenacetin/analysis , Phenacetin/blood , Phenacetin/chemistry , Rats , Rats, WistarABSTRACT
For different reasons, street cocaine is often diluted with pharmacologically active substances, the so-called adulterants such as levamisole or hydroxyzine. A controversial debate exists currently on the uptake of adulterants from cocaine preparations and drug-related death. Previous research convincingly argues that serious adverse side effects that affect the central nervous and cardiovascular systems can be a consequence of adulterated cocaine. AIMS: Having identified the presence of adulterants in lung tissue and blood, the concentrations of these substances in brain, an important target location, was of interest. This provides an opportunity to assess their role in cases of drug-related deaths. MATERIALS AND METHODS: We developed and validated a method for the analysis of cocaine, two cocaine metabolites and six adulterants, which can typically be found in cocaine preparations, and one adulterant metabolite in brain tissue by gas chromatography-mass spectrometry (GC-MS)1. Ten brain samples which were tested positive for cocaine were analyzed. The homogenized brain tissue was embedded into drying paper for protein precipitation. During a subsequent solid-phase extraction (SPE), the eluate and one of the wash fractions were collected. After derivatization with N-Methyl-N-(trimethylsilyl)trifluoroacetamide (MSTFA) in pyridine and isooctane, the extracts were analyzed by GC-MS. RESULTS AND DISCUSSION: The method was fully validated for cocaine (COC), benzoylecgonine (BZE), ecgonine methyl ester (EME), diltiazem (DIL), hydroxyzine (HYD), and levamisole (LEV) and partly validated for cetirizine (CET), lidocaine (LID), phenacetin (PHE), and procaine (PRO) in brain material. By analyzing post-mortem brain tissue of ten cocaine users, LEV, LID, and HYD as well as PHE were identified in contrast to DIL, PRO, and the HYD metabolite CET. HYD and LEV were found in moderate to high concentrations in some cases. Therefore, it cannot be excluded that they have caused adverse side effects. CONCLUSION: Because adulterants can potentially affect the central nervous and cardiac systems, it is likely that they enhance COC toxicity.
Subject(s)
Brain Chemistry , Cocaine-Related Disorders , Cocaine/chemistry , Drug Contamination , Narcotics/chemistry , Cetirizine/analysis , Cocaine/analogs & derivatives , Cocaine/analysis , Diltiazem/analysis , Forensic Toxicology , Gas Chromatography-Mass Spectrometry , Humans , Hydroxyzine/analysis , Levamisole/analysis , Lidocaine/analysis , Narcotics/analysis , Phenacetin/analysis , Reproducibility of Results , Solid Phase ExtractionABSTRACT
An office paper-based colorimetric device is proposed as a portable, rapid, and low-cost sensor for forensic applications aiming to detect phenacetin used as adulterant in illicit seized materials such as cocaine. The proposed method uses white office paper as the substrate and wax printing technology to fabricate the detection zones. Based on the optimum conditions, a linear analytical curve was obtained for phenacetin concentrations ranging from 0 to 64.52µgmLâ1, and the straight line was in accordance with the following equation: (Magenta percentage color) = 1.19 + 0.458 (CPhe/µgmLâ1), R2 = 0.990. The limit of detection was calculated as 3.5µgmLâ1 (3σ/slope). The accuracy of the proposed method was evaluated using real seized cocaine samples and the spike-recovery procedure.
Subject(s)
Cocaine/analysis , Phenacetin/analysis , Colorimetry/economics , Colorimetry/methods , Costs and Cost Analysis , Drug Contamination , Naphthoquinones , Paper , Printing , WaxesABSTRACT
Phenacetin is a pharmaceutical closely related to acetaminophen that has been banned in France for a long time due to its nephritic and carcinogenic adverse effects. It frequently appears in cocaine seizures as a cutting agent. Following both sanitary and intelligence motivations, this molecule was chosen for this study, and stable isotopes seemed to be the most appropriate tool. A total of 228 seized samples were collected over a 6-year period, and 8 standards of known origin were purchased. They were submitted to gas chromatography (GC) or elemental analysis - isotope ratio mass spectrometry (EA-IRMS) measurements, depending on their complexity. Stable isotope ratios of carbon, hydrogen, and nitrogen for a part of the sample set, were acquired. The isotopic values of phenacetin standards acquired from various providers located worldwide are quite spread, which indicates that stable isotopes could be used to discriminate manufacturers. However, the measured values of most of the seized samples are concentrated in a narrow range, tending to demonstrate that phenacetin is smuggled from a single source or similar ones. Consequently, stable isotopes could only be used to exclude that several samples come from a common source. Copyright © 2016 John Wiley & Sons, Ltd.
Subject(s)
Analgesics, Non-Narcotic/chemistry , Cocaine/chemistry , Dopamine Uptake Inhibitors/chemistry , Illicit Drugs/chemistry , Phenacetin/chemistry , Analgesics, Non-Narcotic/analysis , Carbon Isotopes/analysis , Chromatography, Gas/methods , Mass Spectrometry/methods , Phenacetin/analysisABSTRACT
A method was optimized for derivatization, separation, detection and quantification of salicylic acid, acetylsalicylic acid, nalidixic acid, ibuprofen, phenacetin, naproxen, ketoprofen, meclofenamic acid and diclofenac in surface water using gas chromatography-mass spectrometry. For most of the acidic drugs, recovery was in the range 60-110% and the percent standard deviation was below 15% for the entire method, with limits of detection ranging from 0.041 to 1.614 µg L-1. The developed method was applied in the analysis of acidic drugs in Umgeni River system, KwaZulu-Natal South Africa. All of the selected acidic drugs were detected and quantified, their concentration in Umgeni River system ranged from 0.0200 to 68.14 µg L-1.
Subject(s)
Water Pollutants, Chemical/analysis , Acids, Carbocyclic/analysis , Aspirin/analysis , Environmental Monitoring , Gas Chromatography-Mass Spectrometry/methods , Hydrogen-Ion Concentration , Nalidixic Acid/analysis , Naproxen/analysis , Phenacetin/analysis , Rivers/chemistry , South Africa , Water/chemistryABSTRACT
The combination of thin layer chromatography (TLC) and mass spectrometry (MS) has been studied for decades, but for most cases MS detection is done after TLC separation is finished. Here, an online simultaneous TLC-MS analysis system, liquid thin layer chromatography-mass spectrometry (LTLC-MS), is developed which successfully synchronize TLC separation process and MS detection process like GC-MS and HPLC-MS do. And there's no need to use specially designed TLC, just regular TLC plates are enough. LTLC-MS method is composed of a newly developed ambient ionization method, glow discharge-matrix assisted infrared desorption ionization (GD-MAIRDI), and forced-flow TLC (FFTLC) technique, which guarantees the MS detection process does not disturb the TLC separation process throughout the whole analysis. The whole LTLC-MS analysis only need two steps and less than 15min. Mixtures as well as the two main components of a pain relief pills have been successfully analyzed by LTLC-MS. This proof of concept study opens up new possibilities of combining TLC with MS, and will further broaden the application abilities of TLC.
Subject(s)
Analgesics/analysis , Chromatography, High Pressure Liquid/methods , Chromatography, Thin Layer/methods , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization/methods , Aminopyrine/analysis , Analgesics/chemistry , Chromatography, High Pressure Liquid/instrumentation , Chromatography, Thin Layer/instrumentation , Phenacetin/analysis , Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization/instrumentation , Tablets/chemistryABSTRACT
Thin layer chromatography (TLC) is a simple and inexpensive type of chromatography that is extensively used in forensic laboratories for drugs of abuse analysis. In this work, TLC is optimized to analyze cocaine and its adulterants (caffeine, benzocaine, lidocaine and phenacetin) in which the sensitivity (visual determination of LOD from 0.5 to 14mgmL(-1)) and the selectivity (from the study of three different eluents: CHCl3:CH3OH:HCOOHglacial (75:20:5v%), (C2H5)2O:CHCl3 (50:50v%) and CH3OH:NH4OH (100:1.5v%)) were evaluated. Aiming to improve these figures of merit, the TLC spots were identified and quantified (linearity with R(2)>0.98) by the paper spray ionization mass spectrometry (PS-MS), reaching now lower LOD values (>1.0µgmL(-1)). The method developed in this work open up perspective of enhancing the reliability of traditional and routine TLC analysis employed in the criminal expertise units. Higher sensitivity, selectivity and rapidity can be provided in forensic reports, besides the possibility of quantitative analysis. Due to the great simplicity, the PS(+)-MS technique can also be coupled directly to other separation techniques such as the paper chromatography and can still be used in analyses of LSD blotter, documents and synthetic drugs.
Subject(s)
Cocaine/chemistry , Drug Contamination , Narcotics/chemistry , Benzocaine/analysis , Caffeine/analysis , Chromatography, Thin Layer , Humans , Lidocaine/analysis , Mass Spectrometry/methods , Phenacetin/analysisABSTRACT
The abuse of drugs such as street cocaine is known to cause a variety of toxic effects, some of which involve the lungs and often induce lethal complications. While the toxicity of cocaine itself is reviewed well, the influence of toxic effects of its adulterants on the human body is not thoroughly studied. Therefore, we examined heart blood, femoral vein blood and lung tissue from 11 cases for typically used adulterants in cocaine preparations and check whether if the concentrations in the lung tissue are higher than in the blood. The adulterants were isolated using solid-phase (SPE) and liquid-liquid extraction (LLE) and quantified via high-pressure-liquid-chromatography-time-of-flight-mass spectrometry (LC/TOF-MS). Five adulterants, i.e., phenacetin, lidocaine, diltiazem, levamisole and hydroxyzine, were detected. We found out that the concentration of these substances was often higher in the lung than in the analogous analysed body fluids. It should therefore be considered whether - for the determination in the cause of death - the lung should be examined in addition to heart blood, urine or brain tissue.
Subject(s)
Blood Chemical Analysis , Cocaine/chemistry , Drug Contamination , Illicit Drugs/chemistry , Lung/chemistry , Narcotics/chemistry , Chromatography, High Pressure Liquid , Cocaine-Related Disorders/mortality , Diltiazem/analysis , Forensic Toxicology , Humans , Hydroxyzine/analysis , Levamisole/analysis , Lidocaine/analysis , Liquid-Liquid Extraction , Mass Spectrometry/methods , Phenacetin/analysis , Solid Phase ExtractionABSTRACT
Here, gas chromatography with nitrogen phosphorous detector (GC-NPD) method was developed and validated for the quantification of cocaine and adulterants (caffeine, 4-dimethylaminoantipyrine, levamisole, lidocaine and phenacetin) in illicit samples. The method was based on direct dilution of samples in methanol, sonication for 5 min and centrifugation. After appropriate dilution, an aliquot was injected into GC-MS in order to identify the active compounds and into GC-NPD for the analytes quantification. Bupivacaine was used as an internal standard. The method showed to be precise, accurate and linear over a range of 0.5-100% (weight/weight percentages) for all analytes, except phenacetin which showed a linear range between 2% and 100%. The method was successfully applied to 54 samples seized by the Brazilian Federal Police in the International Airport of Sao Paulo and mailing services during the year 2011. All the samples were associated with international trafficking and were apprehended while leaving the country. The purity of cocaine ranged from 16.5% to 91.4%. Cocaine was the only detected active compound in 29.6% of total samples. Among the identified cutting agents, levamisole was the most abundant (55.6% of the total samples) and relative concentrations (weight/weight percentages) ranged from 0.7% to 23%. Lidocaine, caffeine, phenacetin and 4-dimethylaminoantipyrine were also identified in these samples in minor concentrations. In contrast with what we initially hypothesized, drugs intended to international trafficking did not present high cocaine purity and most of the samples were laced with adulterants before leaving Brazil.
Subject(s)
Cocaine/chemistry , Drug Contamination , Narcotics/chemistry , Aminopyrine/analysis , Brazil , Caffeine/analysis , Crime , Gas Chromatography-Mass Spectrometry , Humans , Levamisole/analysis , Lidocaine/analysis , Phenacetin/analysisABSTRACT
In this article, five hundred and thirteen cocaine seizures of the State of Rio Grande do Sul (Brazil) were analyzed by Fourier transform infrared spectroscopy (FT-IR) in the fingerprint region (1800-650 cm(-1)) to profiling and evaluate the pharmaceutical products used as adulterants. Hierarchical cluster analysis (HCA) and principal component analysis (PCA) were used to identify patterns among the samples whereas partial least square discriminant analysis (PLS-DA) and support vector machines discriminant analysis (SVM-DA) were used to classification the cocaine between base and salt. Spectra of standard solid mixtures of cocaine (salt and base), phenacetin, lidocaine and caffeine were used associated with PCA to predict qualitatively the profile of cocaine seizure. In HCA and PCA, salt and base group were formed correctly. Accordingly with predicted profile of the salt samples, they were majority adulterated with caffeine and lidocaine whereas base cocaine was adulterated only with phenacetin. In the discrimant analysis, all methods have classified the cocaine samples correctly with sensitivity and specificity equal to one between salt and base.
Subject(s)
Cocaine/chemistry , Dopamine Uptake Inhibitors/chemistry , Drug Contamination , Caffeine/analysis , Cluster Analysis , Discriminant Analysis , Humans , Lidocaine/analysis , Phenacetin/analysis , Principal Component Analysis , Spectroscopy, Fourier Transform InfraredABSTRACT
A facile and novel preparation strategy based on electrochemical techniques for the fabrication of electrodeposited graphene (EGR) and zinc oxide (ZnO) nanocomposite was developed. The morphology and structure of the EGR-based nanocomposite were investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (XPS) and Raman spectroscopy. Meanwhile, the electrochemical performance of the nanocomposite was demonstrated with cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Due to the synergistic effect of EGR and ZnO nanoparticles, an ultrasensitive electrochemical sensor for acetaminophen (AC) and phenacetin (PCT) was successfully fabricated. The linearity ranged from 0.02 to 10 µM for AC and 0.06 to 10 µM for PCT with high sensitivities of 54,295.82 µA mM(-1) cm(2) for AC and 21,344.66 µA mM(-1) cm(2) for PCT, respectively. Moreover, the practical applicability was validated to be reliable and desirable in pharmaceutical detections. The excellent results showed the promise of the proposed preparation strategy of EGR-transition metal oxide nanocomposite in the field of electroanalytical chemistry.
Subject(s)
Acetaminophen/analysis , Electrochemical Techniques , Graphite/chemistry , Nanocomposites/chemistry , Phenacetin/analysis , Acetaminophen/blood , Electrodes , Humans , Hydrogen-Ion Concentration , Phenacetin/blood , Zinc Oxide/chemistryABSTRACT
Phenacetin is known to be metabolized to N-AcetylParaBenzoQuinoneImine (NAPQI), which is a common metabolite of paracetamol (also called acetaminophen or APAP). The electrochemical conversion of APAP to NAPQI was shown in 1989 by Getek and co-workers, thus demonstrating the capacity of electrochemistry to mimic the formation of NAPQI from APAP as well as from phenacetin. This study focuses on a preparative electrochemical electrolysis associated with quantitative (1)H NMR. On one hand, this method is able to synthesize reactive metabolites in sufficient concentrations and amounts for NMR analysis. On the other hand, NMR allows the simultaneous detection and quantification of all chemical species, in contrast to mass spectrometry. The combination of electrochemistry with quantitative NMR is thus presented as a relevant method for elucidating the degradation of reactive metabolites and may be considered a valuable complementary tool to EC-MS.