Analytical methods to determine cocaine contamination of banknotes from around the world

First liquid chromatography-high resolution mass spectrometry method for the determination of cocaine on banknote dust

PURPOSE

Prevalence measures of sociological interest concerning cocaine presence on banknotes are fraught with (i) the extreme variability of its concentration (seven orders of magnitude); (ii) the high number of banknotes needed for the statistical significance. Banknote dust from counting machines from a large and representative number of banknotes in circulation in a specific area represents the most eligible sample to ascertain cocaine circulation. No chromatographic method is available in this respect. This study aims at developing the first analytical methodology for the determination of cocaine in banknote dust samples.

METHODS

This novel and straightforward approach consists of a simple methanol extraction followed by analytical determinations via ultra-high performance liquid chromatography coupled to Orbitrap high-resolution mass spectrometry.

RESULTS

Satisfactory analytical performance was obtained with a coefficient of determination of 0.996; maximum within-run and between-run precisions were, respectively, 1.85% and 5.20%. Limits of detection and quantification were, respectively, 3 and 9 ng/mL with an overall process efficiency of 93.2%. The method developed was successfully applied to 9 banknote dust samples from local banknote counter machines. The found concentrations ranged from 2.18E + 02 to 2.31E + 03 μg of cocaine per gram of banknote dust and varied only one order of magnitude, much less than cocaine concentration on banknotes.

CONCLUSIONS

To have an idea of cocaine circulation in a geographical area, the sampling of banknote dust, compared to banknotes, consists of tremendous advantages in terms of statistical significance, higher cocaine concentrations, and lower variability: this is crucial from the sociological point of view.

Determination of Cocaine on Banknotes Using Innovative Sample Preparation Coupled With Multiple Calibration Techniques

A method using innovative sample preparation was developed for determination of cocaine on banknotes. Aqueous extraction of cocaine from banknotes was performed using a sonication‐enhanced technique. Quantitation of cocaine was achieved using high performance liquid chromatography (HPLC) with UV detection at 230 nm, whereas identification was accomplished utilizing gas chromatography with mass spectrometry (GC‐MS). Multiple calibration techniques, including the external calibration method (ECM), internal standard method (ISM), and standard addition method (SAM) were incorporated into the experimental design to simultaneously determine cocaine contents and assess matrix effects. Statistical paired t tests confirmed that matrix effects were not significant with the sample preparation employed. No damage to the features of the banknotes was observed from the extraction procedure. Extraction efficiency, spike recovery, and detection limit were also determined. The unique experimental design allowed for ECM, ISM, and SAM to concurrently determine the contents of cocaine on banknotes collected around Metro‐Detroit. The concentration range of cocaine was from 1.58 to 14.7 μg per note, with an average of 6.96 μg per note. The method is simple and suitable for drug analysis and forensic science applications.

Cocaine Detection by a Laser-Induced Immunofluorometric Biosensor

The trafficking of illegal drugs by criminal networks at borders, harbors, or airports is an increasing issue for public health as these routes ensure the main supply of illegal drugs. The prevention of drug smuggling, including the installation of scanners and other analytical devices to detect small traces of drugs within a reasonable time frame, remains a challenge. The presented immunosensor is based on a monolithic affinity column with a large excess of immobilized hapten, which traps fluorescently labeled antibodies as long as the analyte cocaine is absent. In the presence of the drug, some binding sites of the antibody will be blocked, which leads to an immediate breakthrough of the labeled protein, detectable by highly sensitive laser-induced fluorescence with the help of a Peltier-cooled complementary metal-oxide-semiconductor (CMOS) camera. Liquid handling is performed with high-precision syringe pumps and microfluidic chip-based mixing devices and flow cells. The biosensor achieved limits of detection of 7 ppt (23 pM) of cocaine with a response time of 90 s and a total assay time below 3 min. With surface wipe sampling, the biosensor was able to detect 300 pg of cocaine. This immunosensor belongs to the most sensitive and fastest detectors for cocaine and offers near-continuous analyte measurement.

Sustainable green strategy for recovery of glucose from end-of-life euro banknotes

Usually, Euro banknotes are made from cotton substrates and their waste is disposed of in landfill or is incinerated. In order to valorize the end-of-life euro banknotes (ELEBs), the substrates were used in this research for cellulase production via submerged fungal fermentation (SFF), and the resultant fungal cellulase w s used in ELEBs hydrolysis process for extraction of glucose. The experiments were started by exposing the ELEBs to different types of pretreatments, including milling process, alkali (NaOH/urea solution), and acid leaching to remove any contamination (e.g. dyes) and to decrease the crystallinity of cellulose (the main element in cotton substrate) thus increasing the degradation rate during the fermentation process. The effect of pretreatments on the morphology and chemical composition of ELEBs was observed using Scanning Electron Microscope and Energy Dispersive Spectrometry. Afterwards, Trichoderma reesei-DSM76 was used for cellulase production from the treated ELEBs with high cellulase activity (12.97 FPU/g). The resultant cellulase was upscaled in a bioreactor and used in ELEBs hydrolysis. Finally, the results showed that the optimized pretreatment methods (milling followed by leaching process) significantly improved the cellulase activity and glucose recovery, which was estimated by 96%. According to the obtained results, the developed strategy has a great potential for conversion of ELEBs into a glucose product that could be used in biofuels and bioplastics applications.

Detection of cocaine on euro banknotes; Development of a practical approach for the interpretation of suspect cases

The presence of traces of narcotics, particularly cocaine, on banknotes in circulation is a known and widespread fact in all countries. While linked to consumption and trafficking (primary contamination), their spread is due to direct contact with other banknotes during machine counting and cash financial transactions. The mere detection of traces of cocaine on a sample of banknotes is therefore not sufficient evidence to establish the banknote's illegal origin. Increasing levels of contamination are recorded close to (in terms of both place and time) the first direct contact with the substance. The analysis must thus be able to demonstrate that the concentration of narcotics on the banknotes is significantly higher (statistically) in terms of value and frequency than would be expected from background noise alone. Even in that event, however, this evidence has to be substantiated with additional confirmations linking banknotes to the person and this latter to drug trafficking and/or dealing. In general, an in-depth and systematic analysis of all seized banknotes to search for traces of narcotics is not only prohibitive in terms of cost, but also unnecessary. If the sampling procedure is respected, the Swiss Federal Supreme Court actually recognizes IMS (ion mobility spectrometry) as a lawful method for checking the degree of banknote contamination, as well as all the statistical conclusions that can be drawn from it. In special cases, the prosecutor may require confirmation of IMS results by a laboratory test (liquid/gas chromatography-mass spectrometry). Using a non-destructive sampling procedure (suction on swabs) we determined the presence of cocaine on 978 circulating euro banknotes, randomly collected at 5 swiss customs offices, with IMS and LC-MS/MS in order to establish a normal (background) contamination level. A significant proportion (46.4%) of the euro banknotes analysed by LC-MS/MS had cocaine concentrations above the quantification limit (1 ng/swab). However, the extent of contamination is a determining factor: 94.6% of the banknotes in circulation have cocaine concentrations equal to or less than 10 ng/swab and only 3.4% have cocaine concentrations above 20 ng/swab. By comparison, only 27.3% and 13.4% respectively of the seized banknotes (2 real cases) had cocaine concentrations equal to or less than 10 ng/swab, but 63.5% and 86.7% respectively had cocaine concentrations above 20 ng/swab. We also describe a Komolgorov-Smirnov test model used to determine the presence of an "abnormal" level of contamination relative to the reference banknotes (banknotes in circulation or background noise) effectively and within realistic practical and theoretical frameworks. This model provides a quantifiable and statistically significant result that not only simplifies data interpretation, but also facilitates admissibility as forensic evidence in proceedings. When applied to the sized banknotes using both IMS and LC-MS/MS data, we obtain fully consistent and sounding conclusions.

Microfluidic electrochemical immunosensor for the trace analysis of cocaine in water and body fluids

Quick but accurate testing and on-the-spot monitoring of cocaine in oral fluids and urine continues to be an important toxicological issue. In terms of drug testing, a number of devices have been introduced into the market in recent decades, notably for workplace inspection or roadside testing. However, these systems do not always fulfill the requirements in terms of reliability, especially when low cut-off levels are required. With respect to surface water, the presence of anthropogenic small organic molecules such as prescription and over-the-counter pharmaceuticals as well as illicit drugs like cannabinoids, heroin, or cocaine, has become a challenge for scientists to develop new analytical tools for screening and on-site analysis because many of them serve as markers for anthropogenic input and consumer behavior. Here, a modular approach for the detection of cocaine is presented, integrating an electrochemical enzyme-linked immunosorbent assay (ELISA) performed on antibody-grafted magnetic beads in a hybrid microfluidic sensor utilizing flexible tubing, static chip and screen-printed electrode (SPE) elements for incubation, recognition, and cyclic voltammetry measurements. A linear response of the sensor vs. the logarithm of cocaine concentration was obtained with a limit of detection of 0.15 ng/L. Within an overall assay time of 25 minutes, concentrations down to 1 ng/L could be reliably determined in water, oral fluids, and urine, the system possessing a dynamic working range up to 1 mg/L.

Mass Spectrometry-Based Visualization of Molecules Associated with Human Habitats

The cars we drive, the homes we live in, the restaurants we visit, and the laboratories and offices we work in are all a part of the modern human habitat. Remarkably, little is known about the diversity of chemicals present in these environments and to what degree molecules from our bodies influence the built environment that surrounds us and vice versa. We therefore set out to visualize the chemical diversity of five built human habitats together with their occupants, to provide a snapshot of the various molecules to which humans are exposed on a daily basis. The molecular inventory was obtained through untargeted liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis of samples from each human habitat and from the people that occupy those habitats. Mapping MS-derived data onto 3D models of the environments showed that frequently touched surfaces, such as handles (e.g., door, bicycle), resemble the molecular fingerprint of the human skin more closely than other surfaces that are less frequently in direct contact with humans (e.g., wall, bicycle frame). Approximately 50% of the MS/MS spectra detected were shared between people and the environment. Personal care products, plasticizers, cleaning supplies, food, food additives, and even medications that were found to be a part of the human habitat. The annotations indicate that significant transfer of chemicals takes place between us and our built environment. The workflows applied here will lay the foundation for future studies of molecular distributions in medical, forensic, architectural, space exploration, and environmental applications.

An aptamer folding-based sensory platform decorated with nanoparticles for simple cocaine testing

The consumption of illicit drugs such as cannabis, cocaine, and amphetamines is still a major health and social problem, creating an abuse in adults especially. Novel techniques which estimate the drug of abuse are needed for the detection of newly revealed psychoactive drugs. Herein, we have constructed a combinatorial platform by using quantum dots (QDs) and gold nanoparticles (AuNPs) as well as a functional aptamer which selectively recognizes cocaine and its metabolite benzoylecgonine (BE). We have called it an aptamer folding-based sensory device (AFSD). For the fabrication of AFSD, QDs were initially immobilized onto the poly-L-lysine coated μ-well surfaces. Then, the AuNP-aptamer conjugates were bound to the QDs. The addition of cocaine or BE caused a change in the aptamer structure which induced the close interaction of AuNPs with the QDs. Hence, quenching of the fluorescence of QDs was observed depending on the analyte amount. The linearity of cocaine and BE was 1.0-10 nM and 1.0-25 μM, respectively. Moreover, the limits of detection for cocaine and BE were calculated as 0.138 nM and 1.66 μM. The selectivity was tested by using different interfering substances (methamphetamine, bovine serum albumin, codeine, and 3-acetamidophenol). To investigate the use of AFSD in artificial urine matrix, cocaine/BE spiked samples were applied. Also, confirmatory analyses by using high performance liquid chromatography were performed. It is shown that AFSD has a good potential for testing the cocaine abuse and can be easily adapted for detection of various addictive drugs by changing the aptamer according to desired analytes. Copyright © 2016 John Wiley & Sons, Ltd.

Analysis of new synthetic drugs by ion mobility time-of-flight mass spectrometry

Characteristic ion mobility mass spectrometry data, reduced mobility, and limits of detection (signal-to-noise ratio = 3) were determined for six synthetic drugs and cocaine by ion mobility time-of-flight mass spectrometry (IM-TOF-MS) with electrospray ionization (ESI) and atmospheric pressure chemical ionization (APCI). The studied synthetic illicit drugs recently appeared on the recreational drug market as designer drugs and were methylone, 4-MEC (4'-methylethcathinone), 3,4-MDPV (3,4-methylenedioxypyrovalerone), JWH-210 [4-ethylnaphthalen-1-yl-(1-pentylindol-3-yl)methanone], JWH-250 [2-(2-methoxyphenyl)-1-(1-pentyl-1H-indol-3-yl)ethanone], and JWH-203 [1-pentyl-3-(2'-chlorophenylacetyl) indole]. Absolute reduced mobilities in nitrogen were 1.35, 1.28, 1.41, 1.30, 1.18, 0.98, 1.09, and 1.07 cm2V(-1)s(-1), for methylone [M-H]+, methylone [M+H]+, 4-MEC [M-H]+, 4-MEC [M+H]+, 3,4-MDPV [M+H]+, JWH-210 [M+H]+, JWH-250 [M+H]+, and JWH-203 [M+H]+, respectively. Selected illicit drugs are easily identified by IM-TOF-MS during a 100s analysis. Relative Limits of detection ranged from 4 to 400 nM are demonstrated for these compounds. Such relative limits of detection correspond to 14 pg to 2 ng absolute limits of detection. Better detection limits are obtained in APCI mode for all the illicit drugs except cocaine. ESI mode was found to be preferable for the IM-TOF-MS detection of cocaine at trace levels. A single sample analysis is completed in an order of magnitude less time than that for conventional liquid chromatography/mass spectrometry approach. The application allows one to consider IM-TOF-MS as a good candidate for a method to determine quickly the recently surfaced designer drugs marketed on the internet as "bath salts," "spice," and "herbal blends".

Capillary Electrophoresis with UV Detection to Determine Cocaine on Circulated Banknotes

A new methodology employing capillary electrophoresis with UV detection (CE-UV) was developed, validated, and applied to determine the presence of cocaine on Brazilian banknotes. Some of the banknotes analyzed were obtained directly from general circulation (well used) while others were collected from Automated Teller Machines (ATMs) (relatively new). The background electrolyte optimized using Peakmaster 5.1 software was composed of 60 mmol L−1 TRIS(hydroxymethyl)aminomethane and 20 mmol L−1 2-hydroxyisobutyric acid, at pH 8.4. The separation time achieved for cocaine was only 2.5 minutes. The figures of merit obtained in the evaluation of the proposed method were good linearity (r>0.999) in the concentration range of 0.8–8.0 mg L−1 and acceptable limits of detection and quantification (0.2 mg L−1 and 0.8 mg L−1, resp.). The relative standard deviations of the instrumental precision, repeatability (intraday), and intermediate precision (interday) were less than 4.5% (peak area). The accuracy evaluated through comparing the cocaine results for the banknotes determined by the proposed CE-UV method and using an LC-MS/MS method showed no significant difference between the methods (95% confidence level). In the analysis of the samples cocaine was detected on 93% of the circulating banknotes in amounts ranging from 11.5 μg to 2761.9 μg per note.

Development of sheath-flow probe electrospray ionization (SF-PESI)

Probe electrospray ionization (PESI) uses a sharp solid needle as electrospray emitter. This method was found to be applicable to the analysis of real-world samples with high concentrations of salts and detergents without sample pretreatment. Since PESI is only applicable to wet samples but not to dry samples, sheath-flow PESI (SF-PESI) has been developed. The metal needle was inserted into the fine plastic capillary with a protrusion of 0.1-0.2 mm from the capillary terminus. The solvent was supplied continuously through the capillary. At the lowest position of the probe, solvent flowing out from the capillary makes the sample wet and extracts the analytes from the surface. The extracted analytes were electrosprayed at the highest position of the needle. SF-PESI was successfully applied to samples such as narcotics, tablets, bill, fruits, potatoes, etc.

Identification of cocaine and its metabolites in urban wastewater and comparison with the human excretion profile in urine

The most relevant human urinary metabolites of cocaine (nine metabolites) were measured in urban wastewater in Italy and USA. A novel analytical method based on liquid chromatography tandem mass spectrometry allowed the identification of ecgonine, ecgonine methyl ester and the pyrolytic derivatives of cocaine in untreated wastewater. The aim of this study was to verify whether the pattern of cocaine metabolites in wastewater reflected the human excretion profile in urine. The performance of the method was good, with recoveries higher than 60% and limits of quantifications in the low ng/L range. The stability in untreated wastewater was assessed for all metabolites and the best storage condition resulted freezing samples immediately after collection and keep them frozen until analysis. All the selected compounds were measured in wastewater at concentrations up to 1.5 μg/L and their weekly loads were calculated during a five weeks monitoring campaign in Milan (Italy). The profiles of cocaine metabolites in wastewater matched with those in human urine reported in the literature, suggesting that measures in wastewater reflect the real human excretion and that wastewater analysis is suitable for assessing drug consumption. Benzoylecgonine was confirmed as the best target for estimating cocaine use by wastewater analysis, while cocaine itself should not be considered because its amount in wastewater is affected by other environmental sources such as transport, handling and consumption. Results suggested that the measurement of other metabolites in combination with benzoylecgonine might reflect 60% of an administered dose of cocaine providing also information on different patterns of use.

Illicit drugs: contaminants in the environment and utility in forensic epidemiology

The published literature that addresses the many facets of pharmaceutical ingredients as environmental contaminants has grown exponentially since the 1990s. Although there are several thousand active ingredients used in medical pharmaceuticals worldwide, illicit drug ingredients (IDIs) have generally been excluded from consideration. Medicinal and illicit drugs have been treated separately in environmental research even though they pose many of the same concerns regarding the potential for both human and ecological exposure. The overview presented here covers the state of knowledge up until mid-2010 regarding the origin, occurrence, fate, and potential for biological effects of IDIs in the environment. Similarities exist with medical pharmaceuticals, particularly with regard to the basic processes by which these ingredients enter the environment--excretion of unmetabolized residues (including via sweat), bathing, disposal, and manufacturing. The features of illicit drugs that distinguish them from medical pharmaceuticals are discussed. Demarcations between the two are not always clear, and a certain degree of overlap adds additional confusion as to what exactly defines an illicit drug; indeed, medical pharmaceuticals diverted from the legal market or used for non-medicinal purposes ar also captured in discussions of illicit drugs. Also needing consideration as par tof the universe of IDIs are the numerous adulterants and synthesis impurities often encountered in these very impure preparations. many of these extraneous chemicals have high biological activity themselves. In contract to medical pharmaceuticals, comparatively little is know about the fate and effects of IDIs in the environment. Environmental surveys for IDIs have revealed their presence in sewage wastewaters, raw sewage sludge and processed sludge (biosolids), and drinking water. Nearly nothing is known, however, regarding wildlife exposure to IDIs, especially aquatic exposure such as indicated by bioconcentration i tissues. In contrast to pharmaceuticals, chemical monitoring surveys have revealed the presence of certain IDIs in air and monetary currencies--the latter being of interest for the forensic tracking of money used in drug trafficking. Another unknown with regard to IDIs is the accuracy of current knowledge regarding the complete scope of chemical identities of the numerous types of IDIs in actual use (particularly some of the continually evolving designer drugs new to forensic chemistry) as well as the total quantities being trafficked, consumed, or disposed. The major aspect unique to the study of IDI's in the environment is making use of their presence in the environment as a tool to obtain better estimates of the collective usage of illicit drugs across entire communities. First proposed in 2001, but under investigation with field applications only since 2005, this new modeling approach for estimating drug usage by monitoring the concentrations of IDIs (or certain unique metabolites) in untreated sewage has potential as an additional source of data to augment or corroborate the information-collection ability of conventional written and oral surveys of drug-user populations. This still evolving monitoring tool has been called "sewer epidemiology" but is referred to in this chapter by a more descriptive proposed term "FEUDS" (Forensic Epidemiology Using Drugs in Sewage). The major limitation of FEUDS surrounds the variables involved at various steps performed in FEUDS calculations. These variables are summarized and span sampling and chemical analysis to the final numeric calculations, which particularly require a better understanding of IDI pharmacokinetics than currently exists. Although little examined in the literature, the potential for abuse of FEUDS as a tool in law enforcement is briefly discussed. Finally, the growing interest in FEUDS as a methodological approach for estimating collective public usage of illicit drugs points to the feasibility of mining other types of chemical information from sewage. On the horizon is the potential for "sewage information mining" (SIM) as a general approach for measuring a nearly limitless array of biochemical markers that could serve as collective indicators of the specific or general status of public health or disease at the community-wide level. SIM may create the opportunity to view communities from a new perspective--"communities as the patient." This could potentially lead to the paradigm of combining human and ecological communities as a single patient--as an interconnected whole.