Rapid detection of 10 benzodiazepines and metabolites in blood and urine using DART-MS/MS

Benzodiazepines are essential screening targets for common sleeping and sedative drugs used in forensic toxicology. Direct analysis in real-time tandem mass spectrometry was used to rapidly identify 10 benzodiazepines and related metabolites in the blood and urine. The related direct analysis in real-time tandem mass spectrometry parameters were optimized. A liquid-liquid extraction method using ethyl acetate as the extraction solvent was used for sample preparation. The established method was validated and tested on case specimens. The limits of detection of this method ranged from 0.2 to 20 ng/mL and the limits of quantification from 1 to 50 ng/mL. The recoveries ranged from 78.8% to 114%, and the matrix effects were in the range of -21.2% to 17.9%. The precision and repeatability at high and medium concentrations did not exceed 14.6%, and the limit of quantification did not exceed 18.2%, indicating a desirable linear relationship. The established method was used to determine blood and urine specimens from authentic cases, and promising results were obtained.

Overview of the bioanalytical methods used for the determination of benzodiazepines in biological samples and their suitability for emergency toxicological analysis

Benzodiazepines are one of the most widely used classes of drugs around the world. They are medically used in different therapeutic areas including insomnia, anxiety, epilepsy, and anesthesia. Unfortunately, these drugs are very widespread in the illicit market for recreational purposes and cause drug dependence, traffic accidents, and criminality. Furthermore, benzodiazepine misuse leads to acute poisoning cases that often end up in hospital emergency rooms. Therefore, it is crucial for hospitals to possess straightforward and efficient bioanalytical techniques that enable the swift detection of benzodiazepines in biological samples. This review provides a general overview of the different bioanalytical techniques used for the detection and quantification of benzodiazepines in biological samples and emphasizes their suitability for emergency toxicological analyzes.

Cellulose paper sorptive extraction (CPSE): A simple and affordable microextraction method for analysis of basic drugs in blood as a proof of concept

Aiming towards simplifying sample preparation procedure, the present work explores use of unmodified laboratory filter paper as sorbent for extraction of nine basic drugs (five antidepressants, four benzodiazepines, and ketamine) from human blood samples and their analysis by gas chromatography-mass spectrometry (GC-MS). The procedure termed as cellulose paper sorptive extraction (CPSE) is straightforward. It involves adsorption of target analytes from deproteinized diluted blood samples on the unmodified cellulose paper followed by elution into 2 mL of methanol. Multivariate optimization, consisting of Placket-Burman design (PBD) and central composite design (CCD), was used to screen and optimize significant factors for CPSE. The proposed method follows the principles of green analytical chemistry (GAC), as the unmodified filter paper used as the sorbent is inexpensive and biodegradable. The technique is easy to perform and requires only 2 mL of MeOH during the entire extraction procedure. Under the optimized conditions, the limit of detection and quantification for the target analytes were estimated to be in the range of 0.003-0.035 and 0.010-0.117 µg mL^-1, respectively. In contrast, the relative standard deviations were consistently below 10 %. The calibration curves were linear in the range of 0.015-2 µg mL^-1 with a coefficient of determination (R²) in the range of 0.995-0.999.Satisfactory recoveries ranging from 87 to 99 % was achieved. As proof of concept, the analysis of nine drugs in blood samples from the patients was performed to demonstrate the potential application of the proposed method.

Alprazolam Detection Using an Electrochemical Nanobiosensor Based on AuNUs/Fe-Ni@rGO Nanocomposite

Despite all the psychological advantages of alprazolam, its long list of toxic properties and interactions has caused concern and highlighted the need for a reliable sensing method. In this study, we developed a simple, highly sensitive electrochemical nanobiosensor to determine the desirable dose of alprazolam, averting the undesirable consequences of overdose. Gold nanourchins (AuNUs) and iron-nickel reduced graphene oxide (Fe-Ni@rGO) were immobilized on a glassy carbon electrode, which was treated beforehand. The electrode surface was characterized using cyclic voltammetry, Fourier transform infrared spectroscopy, scanning electron microscopy/energy-dispersive X-ray spectroscopy, and differential pulse voltammetry. The fabricated sensor showed two linear ranges (4 to 500 µg L^-1 and 1 to 50 mg L^-1), low limit of detection (1 µg L^-1), high sensitivity, good repeatability, and good recovery. Increased -OH and carboxyl (-COOH) groups on the electrode surface, resulting in improved the adsorption of alprazolam and thus lower limit of detection. This nanobiosensor could detect alprazolam powder dissolved in diluted blood serum; we also studied other benzodiazepine drugs (clonazepam, oxazepam, and diazepam) with this nanobiosensor, and results were sensible, with a significant difference.

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.

Analytical Methods Used for the Detection and Quantification of Benzodiazepines

The prescription of psychotropic drugs, especially benzodiazepines (BZDs), occupies a preponderant place in the management of mental illnesses. Indeed, the BZDs have been used in different therapeutic areas including insomnia, anxiety, seizure disorders, or general anesthesia. Unfortunately, these drugs are present in the illegal street market, leading to a lot of drug abuse amongst some addicted users, road insecurity, and suicide. Hence, it has become essential to analyze the BZDs drugs in human biological specimens for drug abuse in forensic sciences. The present review provides a summary of sample preparation techniques (solid-phase extraction and Liquid-liquid phase extraction) and the methods for the detection and quantification of BZDs molecules in the commonly used biological specimens over the ten last years which may potentially lead to better and accurate evaluation of the physiological state of a given person. The commonly used methods for the detection and quantification of BZDs include nuclear magnetic resonance (NMR), chromatography (GC-MS, HPLC, and TLC), immunoassay (ELISA, RIA, LFA, CEDEA, FPIA, and KIMS), and electroanalytical methods (voltammetry and potentiometry).

Determination of benzodiazepines in pericardial fluid by gas chromatography-mass spectrometry

In Forensic Toxicology it is sometimes impossible to obtain a valid blood sample to perform toxicological analysis due to several factors like advanced state of decomposition, severe burns, bleed to death…. Pericardial Fluid has already been studied during the last years and has been proposed as a valid specimen for toxicological tests. Over the years, the consumption of benzodiazepines spread among the drug dependent population and became noticeable in drug facilitated assault cases and road accidents. Improvement of the analytical methodology required for detecting the presence of these drugs in biological samples is of great importance for forensic toxicology, in order to correctly diagnose an exposure or a poisoning. In this study, 9 benzodiazepines (diazepam, nordiazepam, midazolam, bromazepam, oxazepam, temazepam, lorazepam, clonazepam and alprazolam) have been determined in pericardial fluid. For this purpose a solid phase extraction (SPE) was carried out using Bond Elut Certify cartridges. After the derivatization of six of the nine benzodiazepines, gas chromatography coupled to a selective mass detector was used as the technique for the separation of the analytes. The method developed was fully validated for the 9 analytes and was applied to real samples of pericardial fluid received at the Forensic Toxicology Service of the University of Santiago de Compostela. Finally, they were compared with blood results looking for the existence of a possible correlation between both biological samples.

Study of the retention of benzotriazoles, benzothiazoles and benzenesulfonamides in mixed-mode solid-phase extraction in environmental samples

In the present study, the capabilities of strong cation-exchange and strong anion-exchange sorbents for solid-phase extraction (SPE) have been evaluated for the selective retention of benzotriazoles (BTRs), benzothiazoles (BTs) and benzenesulfonamides (BSAs), which are a group of neutral analytes with interesting properties such as high polarity and the capability of delocalizing electron density. The retention of these analytes has been compared in both sorbents for the first time, using a SPE procedure specially designed to promote ionic retention of the analytes with the objective of including a washing step with an organic solvent to eliminate interferences retained by hydrophobic interactions. As a result, ionic interactions between the analytes and both sorbents were observed, which allowed the successful introduction of a washing step using methanol in the SPE procedure even when most of the analytes were in their neutral state under SPE conditions. Consequently, a method was developed and further validated for each sorbent using liquid chromatography coupled to high-resolution mass spectrometry (LC-HRMS). Apart from the development of an improved method, special attention was paid to the discussion of the interactions present between the sorbents and each group of analytes to explain how these analytes in their neutral state might develop ionic interactions with the sorbents. At the end, the use of these sorbents helped to simplify previous developed methods where hydrophobic/hydrophilic sorbents were used, obtaining enhanced results when evaluated in river water and effluent and influent wastewaters.

Sample preparation with solid phase microextraction and exhaustive extraction approaches: Comparison for challenging cases

In chemical analysis, sample preparation is frequently considered the bottleneck of the entire analytical method. The success of the final method strongly depends on understanding the entire process of analysis of a particular type of analyte in a sample, namely: the physicochemical properties of the analytes (solubility, volatility, polarity etc.), the environmental conditions, and the matrix components of the sample. Various sample preparation strategies have been developed based on exhaustive or non-exhaustive extraction of analytes from matrices. Undoubtedly, amongst all sample preparation approaches, liquid extraction, including liquid-liquid (LLE) and solid phase extraction (SPE), are the most well-known, widely used, and commonly accepted methods by many international organizations and accredited laboratories. Both methods are well documented and there are many well defined procedures, which make them, at first sight, the methods of choice. However, many challenging tasks, such as complex matrix applications, on-site and in vivo applications, and determination of matrix-bound and free concentrations of analytes, are not easily attainable with these classical approaches for sample preparation. In the last two decades, the introduction of solid phase microextraction (SPME) has brought significant progress in the sample preparation area by facilitating on-site and in vivo applications, time weighted average (TWA) and instantaneous concentration determinations. Recently introduced matrix compatible coatings for SPME facilitate direct extraction from complex matrices and fill the gap in direct sampling from challenging matrices. Following introduction of SPME, numerous other microextraction approaches evolved to address limitations of the above mentioned techniques. There is not a single method that can be considered as a universal solution for sample preparation. This review aims to show the main advantages and limitations of the above mentioned sample preparation approaches and the applicability and capability of each technique for challenging cases such as complex matrices, on-site applications and automation.