Fast determination of amphetamine-type stimulants and synthetic cathinones in whole blood samples using protein precipitation and LC-MS/MS

Microextraction Techniques for Sample Preparation of Amphetamines in Urine: A Comprehensive Review

Psychological disorders and dramatic social problems are serious concerns regarding the abuse of amphetamine and its stimulant derivatives worldwide. Consumers of such drugs experience great euphoria along with serious health problems. Determination and quantification of amphetamine-type stimulants are indispensable skills for clinical and forensic laboratories. Analysis of low drug doses in bio-matrices necessitates applications of simple and also effective preparation steps. The preparation procedures not only eliminate adverse matrix effects, but also provide reasonable clean-up and pre-concentration benefits. The current review presents different methods used for sample preparation of amphetamines from urine as the most frequently used biological matrix. The advantages and limitations of various sample preparation methods were discussed focusing on the miniaturized methods.

Illicit drugs in Brazil: environmental consequences and consumption patterns

This article reviews the literature on the consumption, street drug analysis, distribution, and main environmental impacts of illicit drugs in Brazil and analyzes the III National Survey on Drug Use by the Brazilian Population. The literature review is based on articles published in national and international journals between 2018 and 2023. This review consists of two analyses, the first of which addresses publications from the last 6 years on the monitoring of illicit drugs in Brazil and a second analysis based on the III National Survey on Drug Use that addresses the different possibilities of contact with drugs. The results revealed that the Southeast region of Brazil has the highest number of studies on the subject, especially in the state of São Paulo, while the North and Northeast regions have the lowest number of studies. The Midwest regions only have studies in the federal capital city, Brasília, while no studies were found in states bordering countries that produce illicit drugs, such as Paraguay and Bolivia. Analytical methods that use the concept of miniaturization, green chemistry, and the adoption of acceptance methods are frequent in most articles. Chemometric and statistical tools are widely used for the analysis, development, and conclusion of identification and quantification methods. Among the articles studied, there was a predominance in the analysis of cocaine metabolites and cannabis metabolites in the aquatic environment, where their concentrations ranged from 0.01 to 2000 ng L-1. Studies also reported bioaccumulation in marine biota with concentrations of up to 4.58 µg kg-1 for mussels and sediments, posing a risk to algae, crustaceans, and fish. Furthermore, the data show that the consumption of illicit drugs is increasing in Brazil, especially among young people.

Qualitative transformations of street-seized ecstasy over a decade: A case study in Rio de Janeiro (Brazil)

The illegal drug market is constantly evolving, with new drugs being created and existing ones being modified. Adulterants are often added to the mix, and the primary substance may be secretly replaced by a new one. Once-known tablets can now be vastly different from what they are sold as, all due to the pursuit of profit and evasion of current drug regulations. These alterations in drug composition pose a threat to society, as their effects are still not well understood. Therefore, it is crucial for police intelligence and public health development to obtain the chemical profiles of illicit drugs. This study presents the chemical fingerprinting of ecstasy tablets seized in the state of Rio de Janeiro (Brazil) between 2012 and 2021. The tablet samples were weighed, extracted, diluted with methanol, and acidified before analysis using gas chromatography high-resolution mass spectrometry and attenuated total reflection Fourier transform infrared spectroscopy. The major constituents found were MDMA and clobenzorex, with fewer occurrences of MDA, MDEA, and 2C-B. The results also indicate that the occurrence of mega-events in the study location impacted the chemical fingerprints of ecstasy. A total of 27 combinations of cutting agents, including caffeine, ephedrine, and anesthetics, were identified. Samples composed of clobenzorex were observed throughout the evaluated period in areas near highways, suggesting that this product is mainly used by truck drivers. These findings can help police intelligence units anticipate the behavior of the illicit market during major events, identify traffic routes, and support public health initiatives.

What's in drugs freely used by Brazilian truck drivers - "Rebites"? Determination of target and nontarget compounds by high-resolution mass spectrometry and nuclear magnetic resonance

Highways, the lifeline of the Brazilian economy, transport approximately 75% of the country's economic activity, highlighting its importance. However, professional drivers, accustomed to long daily journeys, make use of tablets widely available in Gas Station, which are known as "Rebites," which could contain a mixture of legal and illegal compounds. Thus, this study aims at the chemical characterization of these through different analytical methods. Initially, we performed a comprehensive screening of compounds present in seven samples collected across the country using high-resolution mass spectrometry (HRMS). The findings revealed caffeine as the main compound, alongside theophylline, lidocaine, and clobenzorex, among others. In the next step, we employ quantitative nuclear magnetic resonance (qNMR) to quantify the caffeine content in the tablets. The results indicated a caffeine concentration ranging between 14% and 31% (m/m), which may imply a daily overdose of this compound from around four tablets. In summary, this investigation provides a chemical characterization of real samples of "Rebites" freely obtained along Brazilian highways. Caffeine emerged as the predominant active compound, with its concentration determined by qNMR analysis. The notable presence of caffeine, combined with other stimulants, depressants, and hallucinogens, underscores the need for strict quality control measures regarding "Rebites" to safeguard public health.

A dual-mode biosensor based on silica inverse opal photonic crystals modulated electrochemiluminescence and dye displacement colorimetry for the sensitive detection of synthetic cathinone in water environment

To address the challenges posed by signal capacity limitations and the reliance of sensing methods on single analytical information, this study developed an electrochemiluminescence (ECL) and colorimetric dual-mode sensing platform for the precise detection of 4-chloroethcathinone (4-CEC) in water environments. Firstly, the accurate alignment of the reflection wavelength of appropriately sized silica inverse opal photonic crystals (SIOPCs) with the ECL emission wavelength of luminescent metal-organic frameworks (PCN-224) has been achieved via diameter modulation. This innovative design, which cleverly utilized the band-edge effect, improved the luminous intensity of the ECL sensor, leading to a significant boost in analytical performance. Secondly, the establishment of a colorimetric detection method for confirming the presence of 4-CEC in samples through visual observation of color changes was achieved by employing an aptamer-based dye displacement reaction, utilizing differential binding affinities between the aptamer and both the sulforhodamine B (SRB) and 4-CEC. Under the optimal experimental conditions, the dual-mode sensor demonstrated ECL detection of limits (LOD) of 2.6 × 10-13 g/L and colorimetric LOD of 6.5 ng/L for 4-CEC. These findings highlighted the tremendous potential of developing streamlined and efficient dual-signal readout platforms using ECL aptamer sensors for the precise determination of other Synthetic cathinones (SCs) in water environments.

Rapid and sensitive detection of amphetamine by SERS-based competitive immunoassay coupled with magnetic separation

Amphetamine (AMP), as a psychiatric drug acting on the central nervous system, and has become one of the most common drugs of abuse in the illegal market at present, which adversely affects social public safety. We developed a SERS magnetic immunoassay with high sensitivity, specificity, and rapid and quantitative detection of AMP. We synthesized a high SERS intensity substrate (Au-XP013@Ag) using the "hot spot" effect and combined it with antibodies to form SERS immunotags (Au-XP013@Ag-AMP-mAb). Subsequently, the carboxyl magnetic beads were linked to label antigens as functional magnetic beads (carboxyl magnetic beads-AMP-BSA). Using the principle of competitive immunoassay, the Raman response value of the immune complex formed with SERS tags and functional magnetic beads was detected to realize the quantitative detection of AMP. The detection limit of this method for AMP was 2.28 ng mL^-1. More importantly, a portable Raman instrument was used in this study, which can meet the requirements of point-of-care testing (POCT). Therefore, this SERS-based magnetic immunoassay can provide a favorable scientific basis for the control of drug abuse, monitoring by law enforcement agencies, and determination of drug users.

Analysis of conventional and nonconventional forensic specimens in drug-facilitated sexual assault by liquid chromatography and tandem mass spectrometry

The incidence of drug-facilitated sexual assault (DFSA) has dramatically increased in the last decades. Forensic analytical scientists continuously seek new methods and specimens to prove the incidence of intoxication for the judiciary system. Factors influencing sample selection include the ease of obtaining the samples and the window of detection of the drugs, among others. Both conventional (blood, urine) and non-conventional specimens (hair, nails, fluids) have been proposed as suitable in DFSA cases. Reported sample treatments include a variety of liquid-liquid and solid-phase extraction as well as dilute-and-shoot procedures and microextraction techniques. Regarding analysis, liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) has emerged as the preferred confirmatory technique, due to its sensitivity, selectivity, and wide-scope applicability. In this review, we critically discuss the most common specimens and sample treatments/analysis procedures (related to LC-MS/MS) that have been reported during the last ten years. As a final goal, we intend to provide a critical overview and suggest analytical recommendations for the establishment of suitable analytical strategies in DFSA cases.

Fast Quantitative LC-MS/MS Determination of Illicit Substances in Solid and Liquid Unknown Seized Samples

Narcotic and psychotropic substances are natural, synthetic, or semisynthetic compounds that are present in both solid and liquid illicit products. The alterations effects on the central nervous system related to their use can be psycholeptic, psychoanaleptic, or psychodiseptic and are able to generate tolerance, addiction, or dependence phenomena, creating social and public order problems. In this scenario, the analytical evaluations that aim to determine these analytes in seized nonbiological samples, and which assume the character of judicial evidence, must meet high analytical requirements of reliability, transparency, and procedures uniformity at a national level. For the first time in the literature, the herein validated method is able to provide the simultaneous quantitative determination of 37 of the most common narcotic substances as well as the most commonly used excipients/adulterants found in seized illicit material. Additionally, the validated method can process both solid and liquid samples maintaining the precision and trueness levels (intraday and interday) in accordance with the U.S. Food and Drug Administration and European Medicines Agency international guidelines (<14.31 and <13.41%, respectively). Furthermore, it provides a simple and fast procedure for sample preparation using the dilute and shoot approach, exploiting the sensitivity and selectivity of the LC-MS/MS instrument configuration used and the signal acquisition in multiple reaction monitoring (MRM) mode (both positive and negative polarization modes).

Application of Homogeneous Liquid-Liquid Microextraction with Switchable Hydrophilicity Solvents to the Determination of MDMA, MDA and NBOMes in Postmortem Blood Samples

Synthetic drugs for recreational purposes are in constant evolution and their consumption promote a significant increase in intoxication cases, resulting in damaging public health. The development of analytical methodologies to confirm the consumption of illicit drugs in biological matrices are required for control of these substances. This work exploited the development of an extraction method based on homogenous liquid-liquid microextraction with switchable hydrophilicity solvent as extraction phase (SHS-HLLME) for the determination of the synthetic drugs MDMA, MDA and NBOMes (25B, 25C and 25I) in postmortem blood, followed by liquid chromatography coupled to mass spectrometry in tandem (LC-MS/MS). The optimized sample preparation conditions consisted of using 250 µL of ZnSO4 10% and 50 µL of NaOH 1 mol/L in the protein precipitation step; N,N-dimethylcyclohexylamine (DMCHA) was used as switchable hydrophilicity solvent (SHS), 650 μL of a mixture of SHS:HCl 6 mol/L (1:1 v/v), 500 μL of whole blood, 500 μL of NaOH 10 mol/L and 1 min of extraction time. The proposed method was validated, providing determination coefficients higher than 0.99 for all analytes; LOD and LOQ ranged from 0.1 to 10 ng/mL; intra-run precision from 2.16 to 9.19%; inter-run precision from 2.39 to 9.59%; bias from 93.57 to 115.71%; and matrix effects from 28.94 to 51.54%. The developed method was successfully applied to four authentic postmortem blood samples from synthetic drugs users, and it was found to be reliable with good selectivity.

Simultaneous determination of nine tyrosine kinase inhibitors in three complex biological matrices by using high-performance liquid chromatography-diode array detection combined with a second-order calibration method

An intelligent chemometric second-order calibration method called alternating trilinear decomposition- assisted multivariate curve resolution combined with high-performance liquid chromatography-diode array detection was used for the simultaneous quantification of nine tyrosine kinase inhibitors in three complex biological systems. The method allows simultaneous quantification of the components in different biological matrices without the need for cumbersome pre-treatment steps, complex elution conditions, and complete peak separation. Even with the varying time shift, severe peak overlap, and various unknown interferences, the proposed method can extract pure chromatographic and spectroscopic information for each analyte, while providing accurate qualitative and quantitative results of nine common tyrosine kinase inhibitors in three different biological matrices. All the drugs were eluted in 7 min. The results showed that the nine drugs in each matrix showed good linearity (r > 0.984) in the calibration range with a root mean square error of calibration less than 0.9 μg/mL. The average spiked recoveries of the target analytes were all in the range of 83.4-110.0%, with standard deviations less than 9.0%. Finally, the classical method was used to validate the proposed method. In comparison to the traditional method, the proposed strategy is accuracy, simultaneous, and interference-free.

Determination of 19 Psychoactive Substances in Premortem and Postmortem Whole Blood Samples Using Ultra-High-Performance Liquid Chromatography–Tandem Mass Spectrometry

An ever-increasing need exists within the forensic laboratories to develop analytical processes for the qualitative and quantitative determination of a broad spectrum of new psychoactive substances. Phenylethylamine derivatives are among the major classes of psychoactive substances available on the global market and include both amphetamine analogues and synthetic cathinones. In this work, an ultra-high-performance liquid chromatography-positive ion electrospray ionization tandem mass spectrometric method (UHPLC-ESI-MS/MS) has been developed and fully validated for the determination of 19 psychoactive substances, including nine amphetamine-type stimulants and 10 synthetic cathinone derivatives, in premortem and postmortem whole blood. The assay was based on the use of 1 mL premortem or postmortem whole blood, following solid phase extraction prior to the analysis. The separation was achieved on a Poroshell 120 EC-C18 analytical column with a gradient mobile phase of 0.1% formic acid in acetonitrile and 0.1% formic acid in water in 9 min. The dynamic multiple reaction monitoring used in this work allowed for limit of detection (LOD) and lower limit of quantitation (LOQ) values of 0.5 and 2 ng mL−1, respectively, for all analytes both in premortem and postmortem whole blood samples. A quadratic calibration model was used for the 12 quantitative analytes over the concentration range of 20–2000 ng mL−1, and the method was shown to be precise and accurate both in premortem and postmortem whole blood. The method was applied to the analysis of real cases and proved to be a valuable tool in forensic and clinical toxicology.