Hollow-fibre liquid-phase microextraction and gas chromatography-mass spectrometric determination of amphetamines in whole blood

A LC-MS/MS method for the simultaneous determination of 6-cyanodopamine, 6-nitrodopamine, 6-nitrodopa, 6-nitroadrenaline and 6-bromodopamine in human plasma and its clinical application in patients with chronic kidney disease

The aim of this study was to develop a high-performance liquid chromatography-tandem mass spectrometry method for the determination of 6-cyanodopamine, 6-nitrodopamine, 6-nitrodopa, 6-nitroadrenaline and 6-bromodopamine in human plasma samples. Strata-X 33 μm solid-phase extraction cartridges were used for the extraction of the catecholamines from human plasma samples. The catecholamines were separated in a 150 × 3 mm Shim-pack GIST C18-AQ column with 3 μm particle size, placed in an oven at 40°C and perfused with 82% mobile phase A (acetonitrile-H2O; 90:10, v/v) + 0.4% acetic acid and 18% mobile phase B (deionized H2O) + 0.2% formic acid at a flow rate of 340 μl/min in isocratic mode. The injected volume was 4 μl and the run lasted 4 min. The method was linear from 0.1 to 20 ng/ml and the lower limit of quantification was 0.1 ng/ml for all analytes. The method was applied to evaluate the plasma levels of catecholamines in plasma of patients with chronic kidney disease and allowed the detection for the first time of circulating levels of the novel catecholamines 6-bromodopamine and 6-cyanodopamine.

Research progress on pretreatment technology for the analysis of amphetamine biological samples

Sample pretreatment technology is crucial for drug analysis and detection, because the effect of sample pretreatment directly determinates the final analysis results. In recent years, with the continuous innovation of microextraction and other technologies like material preparation technologies and assistant technologies for extraction, the sample pretreatment techniques in the process of drug analysis have become more and more mature and diverse. This article takes amphetamine (AM) or methamphetamine as an example to review the recent development of pretreatment methods for AM-containing biological samples from the perspectives of extraction techniques, extraction media and auxiliary technologies. Extraction techniques are summarized with the categories of contact microextraction, separate microextraction and membrane-based microextraction for better guidance of application according to their features. Prevailing and innovative extraction media including carbon-based material, silicon-based material, metal organic framework, molecularly selective materials, supramolecular solvents and ionic liquids are reviewed. Auxiliary technologies like magnetic field, electric field, microwave, ultrasound and so on which can enhance extraction efficiency and accuracy are also reviewed. In the last, prospects of the future development of pretreatment technology for the analysis of AM biological samples are provided.

Simultaneous derivatization and extraction of amphetamine and methamphetamine using dispersive liquid-liquid microextraction prior to their analysis using GC-FID in creatine supplements

This study was focused on the development of a sensitive, reliable, and efficient extraction procedure for the determination of amphetamine and methamphetamine utilized in the adulteration of creatine sports supplements. The separation and detection of the analytes were conducted using the gas chromatography-flame ionization detection method. In this study, the analytes were extracted from a supplement powder into a proper solvent by sonication. Then, the extract was mixed with butyl chloroformate to obtain their butylated derivatives and then concentrated by a dispersive liquid-liquid microextraction procedure. The method was performed in a short time. Under optimized extraction conditions, a linear range of 2.01-500 ng g-1 was obtained by a coefficient of determination ≥0.996. Low detection (0.22 ng g-1 and 0.61 ng g-1 for amphetamine and methamphetamine, respectively) and quantification (0.73 ng g-1 and 2.01 ng g-1 for amphetamine and methamphetamine, respectively) limits, good precision (relative standard deviations ≤8.2%), and high extraction recoveries (79% and 86% for amphetamine and methamphetamine, respectively) were achieved. The usefulness of the method in the analysis of the target compounds was confirmed by studying the matrix effect and analysis of the analytes in different real samples.

Green bioanalysis: an innovative and eco-friendly approach for analyzing drugs in biological matrices

Green bioanalytical techniques aim to reduce or eliminate the hazardous waste produced by bioanalytical technologies. A well-organized and practical approach towards bioanalytical method development has an enormous contribution to the green analysis. The selection of the appropriate sample extraction process, organic mobile phase components and separation technique makes the bioanalytical method green. UHPLC-MS is the best option, whereas supercritical fluid chromatography is one of the most effective green bioanalytical procedures. Nevertheless, there remains excellent scope for further research on green bioanalytical methods. This review details the various sample preparation techniques that follow green analytical chemistry principles. Furthermore, it presents green solvents as a replacement for conventional organic solvents and highlights the strategies to convert modern analytical techniques to green methods.

Overview of Different Modes and Applications of Liquid Phase-Based Microextraction Techniques

Liquid phase-based microextraction techniques (LPµETs) have attracted great attention from the scientific community since their invention and implementation mainly due to their high efficiency, low solvent and sample amount, enhanced selectivity and precision, and good reproducibility for a wide range of analytes. This review explores the different possibilities and applications of LPμETs including dispersive liquid–liquid microextraction (DLLME) and single-drop microextraction (SDME), highlighting its two main approaches, direct immersion-SDME and headspace-SDME, hollow-fiber liquid-phase microextraction (HF-LPME) in its two- and three-phase device modes using the donor–acceptor interactions, and electro membrane extraction (EME). Currently, these LPμETs are used in very different areas of interest, from the environment to food and beverages, pharmaceutical, clinical, and forensic analysis. Several important potential applications of each technique will be reported, highlighting its advantages and drawbacks. Moreover, the use of alternative and efficient “green” extraction solvents including nanostructured supramolecular solvents (SUPRASs, deep eutectic solvents (DES), and ionic liquids (ILs)) will be discussed.

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.

Current development of bioanalytical sample preparation techniques in pharmaceuticals

Sample preparation is considered as the bottleneck step in bioanalysis because each biological matrix has its own unique challenges and complexity. Competent sample preparation to extract the desired analytes and remove redundant components is a crucial step in each bioanalytical approach. The matrix effect is a key hurdle in bioanalytical sample preparation, which has gained extensive consideration. Novel sample preparation techniques have advantages over classical techniques in terms of accuracy, automation, ease of sample preparation, storage, and shipment and have become increasingly popular over the past decade. Our objective is to provide a broad outline of current developments in various bioanalytical sample preparation techniques in chromatographic and spectroscopic examinations. In addition, how these techniques have gained considerable attention over the past decade in bioanalytical research is mentioned with preferred examples. Modern trends in bioanalytical sample preparation techniques, including sorbent-based microextraction techniques, are primarily emphasized.

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Bioanalytical sampling techniques are described with suitable applications in pharmaceuticals.

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The pros and cons of each bioanalytical sampling techniques are described.

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Relevant biological matrices are outlined.

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.

Polydopamine-based molecularly imprinted electrochemical sensor for the highly selective determination of ecstasy components

An electrochemical sensor based on molecularly imprinted polydopamine (MIP@PDA) for detecting the main components of ecstasy, MDA and MDMA.

Versatile Integration of Liquid-Phase Microextraction and Fluorescent Aptamer Beacons: A Synergistic Effect for Bioanalysis

Fluorescent aptamer beacons (FABs) are a major category of biosensors widely used in environmental analysis. However, due to their low compatibility, it is difficult to use the common FABs for biological samples. To overcome this challenge, construction of FABs with complex structures to adapt the nature of biological samples is currently in progress in this field. Unlike previous works, we moved our range of vision from the FAB itself to the biological sample. Inspired by this idea, in this work, flat membrane-based liquid-phase microextraction (FM-LPME) with sufficient sample cleanup and preconcentration capacities was integrated with FABs. With the merits of both FM-LPME and FABs, the integrated LPME-FAB system displayed a clear synergistic enhancement for target analysis. Specifically, LPME in the LPME-FAB system provided purified and enriched Hg²⁺ for the FAB recognition, while the FAB recognition event promoted the extraction efficiency of LPME. Due to superior performances, the LPME-FAB system achieved highly sensitive analysis of Hg²⁺ in urine samples with a detection limit of 27 nM and accuracies in the range of 98-113%. To the best of our knowledge, this is the first time that an integrated LPME-FAB system was constructed for target analysis in biological samples. We believe that this study will provide a new insight into the next generation of biosensors, where the integration of sample preparation with detection probes is as important as the design of complex probes in the field of bioanalysis.

Application of HKUST-1 metal-organic framework as coating for headspace solid-phase microextraction of some addictive drugs

In the present study, a copper-based metal-organic framework (HKUST-1) was used first time for preconcentration trace amounts of addictive drugs in biological samples. HKUST-1 was synthesized and coated onto the surface of stainless steel wire. The prepared coating was used in headspace solid-phase microextraction method coupled with gas chromatography-mass spectrometry for preconcentration and determination of some addictive drugs in biological fluids. Prepared coating shows good extraction efficiency due to large surface area, and π-π stacking interaction with selected analytes. Under optimum conditions, the method was validated with a reasonable determination coefficient (R²  > 0.9961) and suitable linear dynamic range (0.5-1000 μg L^-1 ). Also, the limits of detections were obtained in the range of 0.1-0.4, 0.2-0.6, and 0.4-0.7 μg L^-1 for water, urine, and plasma samples, respectively. The limits of quantification of present method were obtained in the range 0.5-1.3, 0.7-1.5, and 1.0-1.9 μg L^-1 in water, urine, and plasma samples, respectively. The intra-day and inter-dye single fiber and fiber to fiber relative standard deviations were observed in the range 3.0-13.9% and 3.5-12.3%, respectively. Finally, the present method was applied for the determination of the drugs in biological samples.

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.

Bioanalysis of pharmaceuticals using liquid-phase microextraction combined with liquid chromatography-mass spectrometry

In this paper, we review recent research articles on liquid-phase microextraction of drug substances from biological fluids, such as plasma, serum, urine, and saliva. We focus on papers where liquid-phase microextraction is combined with liquid chromatography coupled with mass spectrometry (LC-MS), published in the period 2019-2020. First, we discuss different configurations of liquid-phase microextraction, including dispersive liquid-liquid microextraction (DLLME), dispersive liquid-liquid microextraction based on solidified floating organic droplet (DLLME-SFO), single-drop microextraction (SDME), hollow-fibre liquid-phase microextraction (HF-LPME), solvent bar microextraction (SBME), and electromembrane extraction (EME). Second, we discuss new types of solvents used in liquid-phase microextraction, including ionic liquids, deep eutectic solvents, and nanostructured supramolecular solvents. Especially, we focus on the potential for implementation in routine laboratories, which we consider as the next step for liquid-phase microextraction.