First systematic chemical profiling of cocaine police seizures in Finland in the framework of an intelligence-led approach

Irgafos 168 and Irganox 1076 as new cocaine cutting agents: A COVID-19 pandemic impact on cocaine profiling and trafficking in Brazil

BACKGROUNDS

Restrictions in movement and closure of borders imposed by the Sars-Cov- 2 worldwide pandemic have affected the global illicit drug market, including cocaine trafficking. In this scenario, comparing cutting agents added to the cocaine and the drug purity are valuable strategies to understand how the drug trade has been impacted by the pandemic.

METHODS

In this work, 204 cocaine salt materials seized in the Brazilian Federal District, before (2019) and during COVID-19 pandemics (2020) were analyzed by two analytical techniques: gas chromatography-mass spectrometry (GC-MS) and Fourier-transform infrared spectroscopy (FTIR). Statistical analyses, including Principal Component Analysis (PCA), were applied to evaluate the COVID-19 pandemic impact in the local market. Bibliometric analysis was performed as a forensic intelligence tool.

RESULTS

From 2019-2020, cocaine average purity decreased 26 % while the frequency of cutting agents, as caffeine and anesthetics (lidocaine, tetracaine) increased. The high percentage of unknown were increased. Different cocaine profiling seized in 2020 showed new cutting agents, such as Irganox 1076, and Irgafos 168, indicating a trend on new adulterants/diluents introduced in the local market to mitigate the local drug shortage. Also in 2020, there was an increase in the local cocaine seizures, despite of the cocaine drug purity decreased by 26 % compared to 2019.

CONCLUSIONS

Taken together, these data showed that the covid-19 pandemics has impacted cocaine trafficking in the Brazilian Federal District, an increase in cocaine seizures, which may indicate greater demand for the drug and, specially, changes in the cocaine purity and cutting agents profiling showing how traffickers tried to minimize difficulties in crossing the Brazilian border during COVID-19 restrictions. The information is relevant since Brazil is one of the major departure points for traded cocaine to the world. Bibliometric analysis showed that Irgafos 168 and Irganox 1076 were consistently identified as cocaine cutting agents for the first time.

State-of-the-Art Analytical Approaches for Illicit Drug Profiling in Forensic Investigations

In forensic chemistry, when investigating seized illicit drugs, the profiling or chemical fingerprinting of drugs is considered fundamental. This involves the identification, quantitation and categorization of drug samples into groups, providing investigative leads such as a common or different origin of seized samples. Further goals of drug profiling include the elucidation of synthetic pathways, identification of adulterants and impurities, as well as identification of a drug's geographic origin, specifically for plant-derived exhibits. The aim of this state-of-art-review is to present the traditional and advanced analytical approaches commonly followed by forensic chemists worldwide for illicit drug profiling. We discussed numerous methodologies for the physical and chemical profiling of organic and inorganic impurities found in illicit drug. Applications of powerful spectroscopic and chromatographic tools for illicit drug profiling including isotope-Ratio mass spectrometry (IRMS), gas chromatography-mass spectrometry (GC-MS), gas chromatography-isotope ratio mass spectrometry (GC-IRMS), ultra-high-performance liquid chromatography (UHPLC), thin layer chromatography (TLC), liquid chromatography-mass spectrometry (LC-MS) and inductively coupled plasma-mass spectrometry (ICP-MS) were discussed. Altogether, the techniques covered in this paper to profile seized illicit drugs could aid forensic chemists in selecting and applying a suitable method to extract valuable profiling data.

Characterization of 17 unknown ketamine manufacturing by-product impurities by UHPLC-QTOF-MS

This study initially reported the selection and characterization of 17 unknown impurities attributed to the manufacture process of ketamine. A total of 150 seized ketamine samples were investigated through ultra-high-performance liquid chromatography-quadrupole-time of flight (UHPLC-Q-TOF). Seventeen characteristic impurities were selected in accordance with four criteria: The compound was detected in over 10% of all 150 seized ketamine samples, the compound had at least one nitrogen, the unsaturation of the compound was more than 5, and the compound was stable in the dilution solvent solution for 48 h. The accurate masses of the protonated molecules and product ions of the target impurities were obtained based on the full scan mode and the product ion mode of Q-TOF, respectively. Lastly, the possible structures of the above impurities were tentatively elucidated in accordance with the synthetic route of ketamine, protonated molecules, and MS2 product ions. All 17 impurities had the same skeleton of deschloroketamine (DCK), but were substituted with additional chlorine, hydroxyl, methyl, cyclohexane, and o-chlorophenyl cyclopentyl ketone substituents. Under the electrospray ionization (ESI), the above impurities showed similar characteristic fragment ions through the dissociation of the CH3 NH2, C2 H6 NH, H2 O, CO, C2 H4 O, C4 H6 , and C2 H2 moieties. The above impurities have been routinely used for the profiling analysis of seized ketamine samples in the National Narcotics Laboratory of China and employed to establish the tactical intelligence for law enforcement agencies.

Impurities, adulterants and cutting agents in cocaine as potential candidates for retrospective mining of GC-MS data

Cocaine is one of the most widely used illicit drugs worldwide. Cocaine powders seized by the Police may contain numerous other substances besides the drug itself. These can be impurities originating from the coca plant or the production process, or be purposely added to the drug formulation as adulterants and cutting agents. In forensic laboratories, identification of cocaine is routinely done through GC-MS analysis, but other components are often ignored even if the method allows for their detection. Yet, they can provide valuable insight into the history of a seizure and its potential connection to other samples. To explore this idea, an extensive review of common impurities and adulterants encountered in cocaine is presented. Based on their incidence, concentration in the end product and compatibility with GC-MS methods, their overall usefulness as candidates for the statistical investigation of existing forensic data is evaluated. The impurities cis- and trans-cinnamoylcocaine, tropacocaine, norcocaine and N-benzoylnormethylecgonine as well as the adulterants lidocaine, procaine, tetracaine, benzocaine, caffeine, acetylsalicylic acid, phenacetin, ibuprofen, levamisole, hydroxyzine and diltiazem are promising candidates to provide additional forensic intelligence. Future research on optimized routine GC-MS methods, signal reproducibility, comparison, statistics and databases is suggested to facilitate this concept. Ultimately, such an approach may significantly advance the amount of information that is extracted from routine casework data, elucidate developments in the cocaine markets in the past and facilitate Police work in the future. Preliminary assessment of existing data from the forensic laboratory of the Amsterdam Police has been included to show that the detection of the identified target impurities is feasible, and that small adjustments to the analysis method could significantly increase the detectability of these analytes in prospective drug screenings. Forensic intelligence based on retrospective data mining of cocaine containing casework samples may thus be realized with minimal additional laboratory efforts by using already available instrumentation, samples and data.

Gas Chromatographic Fingerprint Analysis for the Comparison of Seized Cannabis Samples

Cannabis sativa L. is widely used as recreational illegal drugs. Illicit Cannabis profiling, comparing seized samples, is challenging due to natural Cannabis heterogeneity. The aim of this study was to use GC–FID and GC–MS herbal fingerprints for intra (within)- and inter (between)-location variability evaluation. This study focused on finding an acceptable threshold to link seized samples. Through Pearson correlation-coefficient calculations between intra-location samples, ‘linked’ thresholds were derived using 95% and 99% confidence limits. False negative (FN) and false positive (FP) error rate calculations, aiming at obtaining the lowest possible FP value, were performed for different data pre-treatments. Fingerprint-alignment parameters were optimized using Automated Correlation-Optimized Warping (ACOW) or Design of Experiments (DoE), which presented similar results. Hence, ACOW data, as reference, showed 54% and 65% FP values (95 and 99% confidence, respectively). An additional fourth root normalization pre-treatment provided the best results for both the GC–FID and GC–MS datasets. For GC–FID, which showed the best improved FP error rate, 54 and 65% FP for the reference data decreased to 24 and 32%, respectively, after fourth root transformation. Cross-validation showed FP values similar as the entire calibration set, indicating the representativeness of the thresholds. A noteworthy improvement in discrimination between seized Cannabis samples could be concluded.

Understanding Australian methylamphetamine drug markets through relational, temporal and spatial analyses

In the area of illicit drugs, forensic case data have proven effective at detecting links between seizures and providing greater insights into illicit drug markets. This research explored the application of mathematical and statistical techniques to several chemical profiles of Australian methylamphetamine seizures. The main aim was to create and deliver a method that would expand the use of illicit drug profiling for strategic intelligence purposes, contributing to the fight against illicit drug trafficking. The use of comparison metrics and clustering analysis to determine links between existing illicit drug specimens and subsequent new specimens was evaluated and automated. Relational, temporal and spatial analyses were subsequently used to gain an insight into illicit drug markets. Relational analysis identified clusters of seizures central to the network. Temporal analysis then provided insights into the behaviour of distribution markets, specifically the emergence and extinction of certain clusters of seizures over time. Spatial analysis aided the understanding of the inter-jurisdictional nature of illicit drug markets. These analyses allowed for the generation of strategic intelligence relating to when and where the Australian methylamphetamine illicit drug market was the most active. Additionally, the strategic level trends identified clusters of seizures that were worth investigating further. These clusters were explored through a case study, which exploited additional chemical profiling data to provide drug market knowledge at an operational level. In turn, the intelligence produced at various levels could allow relevant law enforcement agencies to take necessary measures in disrupting markets.

Cocaine profiling method retrospectively developed with nontargeted discovery of markers using liquid chromatography with time-of-flight mass spectrometry data

Illicit drug profiling performed by forensic laboratories assists law enforcement agencies through providing information about chemical and/or physical characteristics of seized specimens. In this article, a model was developed for the comparison of seized cocaine based on retrospective analysis of data generated from ultrahigh performance liquid chromatography with time‐of‐flight mass spectrometry (UHPLC‐TOF‐MS) comprehensive drug screening. A nontargeted approach to discover target compounds was employed, which generated 53 potential markers using data from cocaine positive samples. Twelve marker compounds were selected for the development of the final profiling model. The selection included a mixture of commonly used cocaine profiling targets and other cocaine‐related compounds. Combinations of pretreatments and comparison metrics were assessed using receiver operating characteristic curves to determine the combination with the best discrimination between linked and unlinked populations. Using data from 382 linked and 34,519 unlinked distances, a classification model was developed using a combination of the standardization and normalization transformations with Canberra distance, resulting in a linked cut‐off with a 0.5% false positive rate. The present study demonstrates the applicability of retrospectively developing a cocaine profiling model using data generated from UHPLC‐TOF‐MS nontargeted drug screening without pre‐existing information about cocaine impurities. The developed workflow was not specific to cocaine and thus could potentially be applied to any seized drug in which there are both sufficient data and impurities present.

Illicit drug profiling practices in Finland: An exploratory study about end users' perceptions

Illicit drug profiling (i.e. chemical and/or physical profiling) to compare and relate illicit drugs samples has been actively used in routine case work at the National Bureau of Investigation (NBI) in Finland. This preliminary and exploratory work reviews NBI's illicit drug profiling practices. Particular emphasis is put on communication of forensic results and how the NBI has promoted the use of forensic data in an intelligence perspective by establishing a case coordination service. Moreover, our study evaluates the comprehension, integration and usefulness of illicit drug profiling from end users' point of view by means of an online survey and face-to-face interviews. Findings are compared with theoretical aspects as described in literature. Results show that in the Finnish context illicit drug profiling is used and useful in the investigation and in court. From end users' perspective, real practical relevance relies in its use as intelligence during the investigation. However, to be truly useful, illicit drug profiling results must be communicated promptly during the investigation, with sufficient clarity and interpreted correctly by end users. Factors influencing the integration of illicit drug profiling in the forensic process are addressed.

Interpreting the link value of similarity scores between illicit drug specimens through a dual approach, featuring deterministic and Bayesian frameworks

Illicit drug trafficking and in particular amphetamine-type stimulants continue to be a major problem in Australia. With the constant evolution of illicit drugs markets, it is necessary to gain as much knowledge about them to disrupt or reduce their impact. Illicit drug specimens can be analysed to generate forensic intelligence and understand criminal activities. Part of this analysis involves the evaluation of similarity scores between illicit drug profiles to interpret the link value. Most studies utilise one of two prominent score evaluation approaches, i.e. deterministic or Bayesian. In previous work, the notion of a dual approach was suggested, which emphasised the complementary nature of the two mentioned approaches. The aim of this study was to assess the operational capability of a dual approach in evaluating similarity scores between illicit drug profiles. Utilising a practical example, link values were generated individually from both approaches, then compared in parallel. As a result, it was possible to generate more informed hypotheses, relating to specimen linkage, due to the greater wealth of information available from the two approaches working concurrently. Additionally, it was shown that applying only one approach led to less information being generated during analysis as well as potentially important links between illicit drug specimens being missed.

Molecularly Imprinted Nanoparticles Based Sensor for Cocaine Detection

The development of a sensor based on molecularly imprinted polymer nanoparticles (nanoMIPs) and electrochemical impedance spectroscopy (EIS) for the detection of trace levels of cocaine is described in this paper. NanoMIPs for cocaine detection, synthesized using a solid phase, were applied as the sensing element. The nanoMIPs were first characterized by Transmission Electron Microscopy (TEM) and Dynamic Light Scattering and found to be ~148.35 ± 24.69 nm in size, using TEM. The nanoMIPs were then covalently attached to gold screen-printed electrodes and a cocaine direct binding assay was developed and optimized, using EIS as the sensing principle. EIS was recorded at a potential of 0.12 V over the frequency range from 0.1 Hz to 50 kHz, with a modulation voltage of 10 mV. The nanoMIPs sensor was able to detect cocaine in a linear range between 100 pg mL-1 and 50 ng mL-1 (R2 = 0.984; p-value = 0.00001) and with a limit of detection of 0.24 ng mL-1 (0.70 nM). The sensor showed no cross-reactivity toward morphine and a negligible response toward levamisole after optimizing the sensor surface blocking and assay conditions. The developed sensor has the potential to offer a highly sensitive, portable and cost-effective method for cocaine detection.

Multi-drug cocktails: Impurities in commonly used illicit drugs seized by police in Queensland, Australia

BACKGROUND

Impurities in commonly used illicit drugs raise concerns for unwitting consumers when pharmacologically active adulterants, especially new psychoactive substances (NPS), are used. This study examines impurities detected in illicit drugs seized in one Australian jurisdiction.

METHODS

Queensland Health Forensic and Scientific Services provided analytical data. Data described the chemical composition of 9346 samples of 11 illicit drugs seized by police during 2015-2016. Impurities present in primary drugs were summarized and tabulated. A systematic search for published evidence reporting similar analyses was conducted.

RESULTS

Methamphetamine was the primary drug in 6608 samples, followed by MDMA (1232 samples) and cocaine (516 samples). Purity of primary drugs ranged from ∼30% for cocaine, 2-CB and GHB to >90% for THC, methamphetamine, heroin and MDMA. Methamphetamine and MDMA contained the largest variety of impurities: 22 and 18 variants, respectively. Drug adulteration patterns were broadly similar to those found elsewhere, including NPS, but in some primary drugs impurities were found which had not been reported elsewhere. Psychostimulants were adulterated with each other. Levamisole was a common impurity in cocaine. Psychedelics were adulterated with methamphetamine and NPS. Opioids were quite pure, but some samples contained methamphetamine and synthetic opioids.

CONCLUSIONS

Impurities detected were mostly pharmacologically active adulterants probably added to enhance desired effects or for active bulking. Given the designer nature of these drug cocktails, the effects of the adulterated drugs on users from possible complex multi-drug interactions is unpredictable. Awareness-raising among users, research into complex multi-drug effects and ongoing monitoring is required.

When does the cutting of cocaine and heroin occur? The first large-scale study based on the chemical analysis of cocaine and heroin seizures in Switzerland

BACKGROUND

Illicit drug profiling can provide knowledge about illicit drug markets, informing on the level of distribution and its evolution in space and time. Illicit drug profiling is usually limited to impurities originally present in the illicit drug (e.g. alkaloids, co-extracted compounds or by-products). However, the benefit of a comprehensive analysis of cutting agents in drug seizures for law enforcement agencies, intelligence and health policy has not been thoroughly investigated in the literature and is the focus of this research.

AIM

This research aims at assessing when and how cutting (i.e. adulteration and dilution) occurs in the supply chain by analysing cocaine and heroin seizures made between 2006 and 2015 in Switzerland.

METHODS

Cocaine and heroin seizures made along the supply chain by law enforcement agencies in the Western region of Switzerland were investigated for adulteration and dilution. A total number of 7841 cocaine and 3476 heroin specimens coming from 1341 and 721 seizures, respectively, were analysed.

RESULTS

The results show that, for both illicit drugs, adulteration and/or dilution occur before arrival into Switzerland as well as in Switzerland. While cocaine is adulterated and diluted, heroin is only adulterated. Interestingly, the same mixture of adulterants (i.e. caffeine-paracetamol) is used to cut heroin at each step in the supply chain.

CONCLUSION

Gaining knowledge about adulteration and dilution at different stages in the supply chain enhances our understanding of drug markets. It also highlights differences along the supply chain and in the distribution of both drugs in Switzerland.

Chemometrics in forensic chemistry - Part I: Implications to the forensic workflow

The forensic literature shows a clear trend towards increasing use of chemometrics (i.e. multivariate analysis and other statistical methods). This can be seen in different disciplines such as drug profiling, arson debris analysis, spectral imaging, glass analysis, age determination, and more. In particular, current chemometric applications cover low-dimensional (e.g. drug impurity profiles) and high-dimensional data (e.g. Infrared and Raman spectra) and are therefore useful in many forensic disciplines. There is a dominant and increasing need in forensic chemistry for reliable and structured processing and interpretation of analytical data. This is especially true when classification (grouping) or profiling (batch comparison) is of interest. Chemometrics can provide additional information in complex crime cases and enhance productivity by improving the processes of data handling and interpretation in various applications. However, the use of chemometrics in everyday work tasks is often considered demanding by forensic scientists and, consequently, they are only reluctantly used. This article and following planned contributions are dedicated to those forensic chemists, interested in applying chemometrics but for any reasons are limited in the proper application of statistical tools - usually made for professionals - or the direct support of statisticians. Without claiming to be comprehensive, the literature reviewed revealed a sufficient overview towards the preferably used data handling and chemometric methods used to answer the forensic question. With this basis, a software tool will be designed (part of the EU project STEFA-G02) and handed out to forensic chemist with all necessary elements of data handling and evaluation. Because practical casework is less and less accompanied from the beginning to the end out of the same hand, more and more interfaces are built in through specialization of individuals. This article presents key influencing elements in the forensic workflow related to the most meaningful chemometric application and evaluation.

Profiling of cocaine using ratios of GC-MS peaks

Illicit cocaine seizures are often compared to each other by using gas chromatography-mass spectrometry (GC-MS) data from cocaine alkaloid compounds to determine whether two specimens originate from the same production batch or not. This can provide intelligence or investigative information at the early stages of an investigation or evidence in court. Traditional classification methods assume high stability of all alkaloids, use all of them to calculate the correlation between two profiles and use a threshold to classify samples. Unstable alkaloids will have a strong influence on the performance. We show that comparing each alkaloid target compound individually improves the classification. Unfortunately, it requires normalization and is also sensitive to the stability. Instead we suggest to use ratios of all possible pairwise combinations of the GC-MS peaks. These ratios are scale free and directly comparable between samples. The peaks can be given different weights in the comparison of profiles using appropriate classification methods and we show that randomForest classification using these ratios have a high and reproducible performance in comparison with other methods. The performance of this method is not affected by noise, transformation or normalization and should be considered for future comparison of chromatographic profiles in general.

Levamisole in Illicit Trafficking Cocaine Seized: A One-Year Study

Cocaine use is increasing around the world and its purity is frequently altered through dilution, substitution, contamination, and adulteration. Sugars, talc, starch, and carbonates represent the principal diluents of cocaine, while phenacetin, levamisole, caffeine, and lidocaine are its major adulterants in Europe. Levamisole is used because it is an odorless powder, with physical properties similar to cocaine, and it has reasonable cost and availability, being widely used in veterinary medicine. For this study, we analyzed 88 cocaine samples. The seized cocaine analyzed showed an average purity of 55% and the most frequent adulterants identified were: levamisole (31.8%), caffeine (6.8%), lidocaine (2.3%), acetaminophen (2.3%), and phenacetin (1.1%). Our aim is the study of the presence of levamisole, over other adulterants in seized cocaine samples, due to its recognized human toxicity. The chronic use of levamisole-adulterated cocaine represents a serious public health issue because it may be responsible for side-effects such as dermal vasculopathy, leukoencephalopathy, leukopenia, agranulocytosis, pulmonary hemorrhage, multiple emboli, and several other effects. Moreover, aminorex can cause idiopathic pulmonary hypertension, presenting another harmful and mostly lethal side-effect from cocaine cut with levamisole. In conclusion, levamisole determination should be performed in routine toxicological analysis in deaths due to cocaine use.

Qualitative, quantitative and temporal study of cutting agents for cocaine and heroin over 9 years

Forensic laboratories mainly focus on the qualification and the quantitation of the illicit drug under analysis as both aspects are used for judiciary purposes. Therefore, information related to cutting agents (adulterants and diluents) detected in illicit drugs is limited in the forensic literature. This article discusses the type and frequency of adulterants and diluents detected in more than 6000 cocaine specimens and 3000 heroin specimens, confiscated in western Switzerland from 2006 to 2014. The results show a homogeneous and quite unchanging adulteration for heroin, while for cocaine it could be characterised as heterogeneous and relatively dynamic. Furthermore, the results indicate that dilution affects more cocaine than heroin. Therefore, the results provided by this study tend to reveal differences between the respective structures of production or distribution of cocaine and heroin. This research seeks to promote the systematic analysis of cutting agents by forensic laboratories. Collecting and processing data related to the presence of cutting agents in illicit drug specimens produces relevant information to understand and to compare the structure of illicit drug markets.