Oxidized multiwalled carbon nanotubes coated fibers for headspace solid-phase microextraction of amphetamine-type stimulants in human urine

Application of novel metal organic framework-deep eutectic solvent/molecularly imprinted polymer multiple monolithic fiber for solid phase microextraction of amphetamines and modafinil in unauthorized medicinal supplements with GC-MS

The goal of this research is the development of multiple monolithic fiber-solid phase microextraction (MMF-SPME) using a new integrated fiber for the determination of amphetamine derivatives and modafinil from unauthorized medicinal supplements. For this purpose, a monolithic fiber of metal organic framework MIL-Al (53)-deep eutectic solvent (DES)/molecularly imprinted polymers (MOF-DES/MIP) was synthesized. To find optimum microextraction conditions gas chromatography-mass spectrometer (GC-MS) was used and the influences of effective variables were investigated using one factor at a time method. After that, the significant variables were optimized using a Box-Behnken design (BBD) combined with a desirability function (DF). Under optimized conditions (desorption solvent=1500 µL of 1-octanol, pH=3.5, extraction time=35 min, [NaCl]=0% w/v and stirring rate=600 rpm), calibration graphs of analytes were linear in a concentration range of 0.1-400 μg L-1 with correlation coefficients > 0.9966. Limits of detection and quantification were in the ranges of 0.023-0.033 μg L-1 and 0.088-0.113 μg L-1, respectively. This procedure was successfully employed in determining target analytes in spiked and unspiked unauthorized medicinal supplement samples with recoveries ranging from 95.14 to 104.63%.

Recent advances in the use of SPME for drug analysis in clinical, toxicological, and forensic medicine studies

Solid-phase microextraction (SPME) has gained attention as a simple, fast, and non-exhaustive extraction technique, as its unique features enable its use for the extraction of many classes of drugs from biological matrices. This sample-preparation approach consolidates sampling and sample preparation into a single step, in addition to providing analyte preconcentration and sample clean-up. These features have helped SPME become an integral part of several analytical protocols for monitoring drug concentrations in human matrices in clinical, toxicological, and forensic medicine studies. Over the years, researchers have continued to develop the SPME technique, resulting in the introduction of novel sorbents and geometries, which have resulted in improved extraction efficiencies. This review summarizes developments and applications of SPME published between 2016 and 2022, specifically in relation to the analysis of central nervous system drugs, drugs used to treat cardiovascular disorders and bacterial infections, and drugs used in immunosuppressive and anticancer therapies.

Rapid detection and speciation of illicit drugs via a thin-film microextraction approach for wastewater-based epidemiology study

High detection frequency of illicit drugs in water samples urges the development of rapid detection method for wastewater-based epidemiology (WBE) study. Here, we first developed a fast, convenient, and cost-effective method by combining thin-film microextraction (TFME) with gas chromatography-mass spectrometry (GC-MS) for sensing illicit drugs in wastewater sample. A divinylbenzene particle-loaded membrane was prepared by dip coating on a copper mesh. The sampling conditions of three illicit drugs were optimized and the performance of the proposed method was evaluated. The limit of detection was 5.5 2.0, and 1.1 ng L^-1 for methamphetamine (MAMP), ketamine (KET), and methaqualone (MEQA), respectively, with acceptable precision (< 6.1 % for membrane to membrane reproducibility) and recovery from influent water (95 % - 111 %). Then, the proposed method was applied to study the occurrence and distribution of the target compounds in a wastewater treatment plant. The presence of methamphetamine, ketamine, and methaqualone was confirmed and their concentrations in the influent sample were 57 ± 8, 40 ± 4, and 75 ± 2 ng L^-1, respectively. The speciation of the target compounds in different ponds was also investigated. Results showed that the content of organic matter and the pH of the sample significantly affected the binding state of the compounds. This work provides an efficient and accurate analytical protocol for WBE investigation of illicit drugs.

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.

Urinary bio-monitoring of amphetamine derivatives by needle trap device packed with the zirconium-based metal-organic framework

In this research, zirconium-based metal–organic framework was utilized as a novel and efficient porous adsorbent for headspace extraction of Amphetamine, Methamphetamine, and Fenfluramine from the urine samples by a needle trap device (NTD). The Zr-UiO-66-PDC was electrosynthesized at the green conditions and characterized by various analyses such as FT-IR, XRD, FE-SEM, EDS, and elemental mapping techniques. Then, the effective parameters on the NTD efficiency such as salt content, pH, extraction/desorption temperature and time were evaluated and optimized by response surface methodology. The optimal extraction of amphetamine compounds was accomplished in 50 min at 70 ºC at the situation with NaCl content of 27% and pH: 11.90. The limit of detection, and limit of quantification factors were determined to be 0.06–0.09 and 0.5–0.8 ng mL⁻¹, respectively. Furthermore, the precision and accuracy (intra- and inter-day) of the employed procedure in the term of relative standard deviation (RSD) were calculated in the range of 8.0–9.0% and 6.8–9.8%, respectively. Also, the recovery percent of the extracted analytes were concluded in the range of 95.0–97.0% after 10 days from the sampling and storage at 4 °C. Finally, the proposed procedure was involved in the analysis of amphetamine compounds in the real urine samples. These results were proved the proposed Zr-UiO-66-PDC@HS-NTD technique coupled with GC-FID can be used as an eco-friendly, fast-response, sensitive, and efficient drug test procedure for trace analysis of the amphetamine compounds in urine samples.

The DI-SPME Method for Determination of Selected Narcotics and Their Metabolites, and Application to Bone Marrow and Whole Blood Analysis

The present investigation utilised the quick and easy SPME/LC-MS method to determine selected narcotic substances and their metabolites in whole blood. The study included qualitative analysis and validation of the method. Analytes were determined in the linearity range of 25−300 ng/mL. The precision during and between days (in general CV < 13.41%), and the LOD which results in between 0.36 and 11.08 ng/mL, and the LOQ between 1.20 and 36.90 ng/mL were investigated. The validation results obtained, as well as the results of subsequent in-laboratory tests, confirmed the applicability of the method in the analysis of blood samples. An attempt to apply the method to the analysis of bone marrow samples has yielded promising results; however, more detailed studies are needed in this area.

Novel Applications of Microextraction Techniques Focused on Biological and Forensic Analyses

In recent years, major attention has been focused on microextraction procedures that allow high recovery of target analytes, regardless of the complexity of the sample matrices. The most used techniques included liquid-liquid extraction (LLE), solid-phase extraction (SPE), solid-phase microextraction (SPME), dispersive liquid-liquid microextraction (DLLME), microextraction by packed sorbent (MEPS), and fabric-phase sorptive extraction (FPSE). These techniques manifest a rapid development of sample preparation techniques in different fields, such as biological, environmental, food sciences, natural products, forensic medicine, and toxicology. In the biological and forensic fields, where a wide variety of drugs with different chemical properties are analyzed, the sample preparation is required to make the sample suitable for the instrumental analysis, which often includes gas chromatography (GC) and liquid chromatography (LC) coupled with mass detectors or tandem mass detectors (MS/MS). In this review, we have focused our attention on the biological and forensic application of these innovative procedures, highlighting the major advantages and results that have been accomplished in laboratory and clinical practice.

Novel solid-phase microextraction fiber coatings: A review

The materials used for the fabrication of solid-phase microextraction fiber coatings in the past five years are summarized in the current review, including carbon, metal-organic frameworks, covalent organic frameworks, aerogel, polymer, ionic liquids/poly (ionic liquids), metal oxides, and natural materials. The preparation approaches of different coatings, such as sol-gel technique, in-situ growth, electrodeposition, and glue methods, are briefly reviewed together with the evolution of the supporting substrates. In addition, the limitations of the current coatings and the future development directions of solid-phase microextraction are presented.

Simultaneous trace-level monitoring of seven opioid analgesic drugs in biological samples by pipette-tip micro solid phase extraction based on PVA-PAA/CNT-CNC composite nanofibers followed by HPLC-UV analysis

Electrospun poly(vinyl alcohol)-(PVA)-poly(acrylic acid) (PAA)/carbon nanotubes(CNTs)-cellulose nanocrystal (CNC) (PVA-PAA/CNT-CNC) composite nanofibers were prepared and characterized using Fourier transform-infrared spectroscopy and field emission scanning electron microscopy. The resultant composite was used as an effective and novel sorbent for pipette-tip micro-solid phase extraction (PT-μSPE) of seven opioid analgesics (OAs) in biological samples followed by HPLC-UV analysis. Addition of CNT-CNC with the high specific surface area and plenty of OH-functional groups endows the nanofibers with considerable extraction efficiency. Under the optimum conditions, the linearity was obtained in the range 1.5 to 700.0 ng mL^-1 for morphine, codeine, oxycodone, and tramadol, and 0.5 to 1000.0 ng mL^-1 for nalbuphine, thebaine, and noscapine with coefficient of determination (r²) ≥ 0.9990. Detection limits (LODs) based on S/N = 3 were in the range of 0.15-0.50 ng mL^-1. The relative standard deviations (RSDs) of 4.1-5.4% (intra-day, n = 5) and 5.2-6.4% (inter-day, n = 3) for three consecutive days were achieved. Finally, the efficiency of the PT-μSPE-HPLC-UV method was evaluated for the determination of OAs in human plasma and urine samples with good recoveries (87.3 to 97.8%). A: Schematic illustration for the preparation of PVA-PAA/CNT-CNC composite nanofibers. B: Schematic presentation of applying PVA-PAA/CNT-CNC composite nanofibers as the sorbent in pipette-tip micro solid-phase extraction (PT-μSPE) for the preconcentration of seven opioid analgesic drugs in biological samples before HPLC-UV analysis.

Application of Microextraction-Based Techniques for Screening-Controlled Drugs in Forensic Context-A Review

The analysis of controlled drugs in forensic matrices, i.e., urine, blood, plasma, saliva, and hair, is one of the current hot topics in the clinical and toxicological context. The use of microextraction-based approaches has gained considerable notoriety, mainly due to the great simplicity, cost-benefit, and environmental sustainability. For this reason, the application of these innovative techniques has become more relevant than ever in programs for monitoring priority substances such as the main illicit drugs, e.g., opioids, stimulants, cannabinoids, hallucinogens, dissociative drugs, and related compounds. The present contribution aims to make a comprehensive review on the state-of-the art advantages and future trends on the application of microextraction-based techniques for screening-controlled drugs in the forensic context.

Recent applications of microextraction sample preparation techniques in biological samples analysis

Analysis of biological samples is affected by interfering substances with chemical properties similar to those of the target analytes, such as drugs. Biological samples such as whole blood, plasma, serum, urine and saliva must be properly processed for separation, purification, enrichment and chemical modification to meet the requirements of the analytical instruments. This causes the sample preparation stage to be of undeniable importance in the analysis of such samples through methods such as microextraction techniques. The scope of this review will cover a comprehensive summary of available literature data on microextraction techniques playing a key role for analytical purposes, methods of their implementation in common biological samples, and finally, the most recent examples of application of microextraction techniques in preconcentration of analytes from urine, blood and saliva samples. The objectives and merits of each microextration technique are carefully described in detail with respect to the nature of the biological samples. This review presents the most recent and innovative work published on microextraction application in common biological samples, mostly focused on original studies reported from 2017 to date. The main sections of this review comprise an introduction to the microextraction techniques supported by recent application studies involving quantitative and qualitative results and summaries of the most significant, recently published applications of microextracion methods in biological samples. This article considers recent applications of several microextraction techniques in the field of sample preparation for biological samples including urine, blood and saliva, with consideration for extraction techniques, sample preparation and instrumental detection systems.

Counterfeit formulations: analytical perspective on anorectics

Purpose

This paper examines the scope of anorectics in counterfeit weight-reducing formulations and provides insight into the present state of research in determining such adulterants. Analytical techniques utilised in profiling adulterants found in slimming products, including limitations and mitigation steps of these conventional methods are also discussed. The current legal status of the anorectics and analogues routinely encountered in non-prescription slimming formulations is also explored.

Methods

All reviewed literature was extracted from Scopus, Web of Science, PubMed, and Google Scholar databases using relevant search terms, such as, ‘counterfeit drugs’, ‘weight loss drugs’, ‘weight-reducing drugs’, ‘slimming drugs’, ‘anorectic agents’, and ‘counterfeit anorexics’. Legislation related to anorectics was obtained from the portals of various government and international agencies.

Results

Anorectics frequently profiled in counterfeit slimming formulations are mostly amphetamine derivatives or its analogues. Five routinely reported pharmacological classes of adulterants, namely anxiolytics, diuretics, antidepressants, laxatives, and stimulants, are mainly utilised as coadjuvants in fake weigh-reducing formulations to increase bioavailability or to minimise anticipated side effects. Liquid and gas chromatography coupled with mass spectrometric detectors are predominantly used techniques for anorectic analysis due to the possibility of obtaining detailed information of adulterants. However, interference from the complex sample matrices of these fake products limits the accuracy of these methods and requires robust sample preparation methods for enhanced sensitivity and selectivity. The most common anorectics found in counterfeit slimming medicines are either completely banned or available by prescription only, in many countries.

Conclusions

Slimming formulations doped with anorectic cocktails to boost their weight-reducing efficacy are not uncommon. Liquid chromatography combined with mass spectrometry remains the gold standard for counterfeit drug analysis, and requires improved preconcentration methods for rapid and quantitative identification of specific chemical constituents. Extensive method development and validation, targeted at refining existing techniques while developing new ones, is expected to improve the analytical profiling of counterfeit anorectics significantly.

MASS SPECTROMETRY ANALYSIS OF DRUGS OF ABUSE: CHALLENGES AND EMERGING STRATEGIES

Mass spectrometry has been the "gold standard" for drugs of abuse (DoA) analysis for many decades because of the selectivity and sensitivity it affords. Recent progress in all aspects of mass spectrometry has seen significant developments in the field of DoA analysis. Mass spectrometry is particularly well suited to address the rapidly proliferating number of very high potency, novel psychoactive substances that are causing an alarming number of fatalities worldwide. This review surveys advancements in the areas of sample preparation, gas and liquid chromatography-mass spectrometry, as well as the rapidly emerging field of ambient ionization mass spectrometry. We have predominantly targeted literature progress over the past ten years and present our outlook for the future. © 2020 Periodicals, Inc. Mass Spec Rev.

Solid phase microextraction as a powerful alternative for screening of secondary metabolites in actinomycetes

Actinobacteria are one of the most promising producers of medically and industrially relevant secondary metabolites. However, screening of such compounds in actinobacteria growth demands simple, fast, and efficient extraction procedures that enable detection and precise quantification of biologically active compounds. In this regard, solid phase microextraction (SPME) emerges as an ideal extraction technique for screening of secondary metabolites in bacteria culture due to its non-exhaustive, minimally invasive, and non-destructive nature: its integrated sample preparation workflow; balanced coverage feature; metabolism quenching capabilities; and superior cleanup, as well as its versatility in configuration, which enables automation and high throughput applications. The current work provides a comparison of micro-scale and direct immersion SPME (DI-SPME) for screening of secondary metabolites, describes the optimization of the developed DI-SPME method, and introduces the developed technique for mapping of target secondary metabolites as well as its direct coupling to mass spectrometry for such applications. The optimized DI-SPME method provided higher amounts of extracted ions and intensity signals, yielding superior extraction and desorption efficiency as compared with micro-scale extraction. Studied compounds presented stability on the coating for 24 h at room temperature. The DI-SPME mapping approach revealed that lysolipin I and the lienomycin analog are distributed along the center and edges of the colony, respectively. Direct coupling of SPME to MS provided a similar ions profile as SPME-LC-MS while enabling a significant decrease in analysis time, demonstrating its suitability for such applications. DI-SPME is herein presented as an alternative to micro-scale extraction for screening of secondary metabolites in actinobacteria solid medium, as well as a feasible alternative to DESI-IMS for mapping of biologic radial distribution of secondary metabolites and cell life cycle studies. Lastly, the direct coupling of DI-SPME to MS is presented as a fast, powerful technique for high throughput analysis of secondary metabolites in this medium.

Developed nano carbon-based coating for simultaneous extraction of potent central nervous system stimulants from urine media by stir bar sorptive extraction method coupled to high performance liquid chromatography

A nano graphene oxide sol-gel composite (NGO/sol-gel) applied as a coating of a capillary glass tube stir bar to develop a novel stir bar sorptive extraction (SBSE) method for simultaneous extraction of amphetamine (AMP) and methamphetamine (MET) from biological urine sample. Lab-synthesized NGO was applied with methyltrimethoxysilane (MTMOS) and Tetraethoxysilane (TEOS) as sol-gel precursor. NGO/sol-gel was deposited on the surface of a capillary glass tube to prepare stir bar sorptive extraction adsorbent by a simple and fast method. The scanning electron micrograph images showed a three dimensional structure of lab-made device suitable for SBSE method for simultaneous extraction of AMP and MET. Effective extraction parameters were investigated. Through studied suitable extraction conditions, satisfactory linearity was achieved in the concentration range of 50-2000 ngmL^-1 for AMP and 40-2500 ngmL^-1 for MET. The relative recovery of the analytes were 99.5 and 99.7% for AMP and MET, respectively for positive urine samples were studied by novel introduced method. The results cleared that NGO/sol-gel composite could be used as practical method in laboratories as an efficient SBSE adsorbent for drugs determination in urine matrix.