Ionic-liquid-based dispersive liquid-liquid microextraction coupled with high-performance liquid chromatography for the forensic determination of methamphetamine in human urine

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.

Determination of Methamphetamine by High-Performance Liquid Chromatography in Odor-Adsorbent Material Used for Training Drug-Detection Animals

The objective of the present report was to develop and validate a simple, sensitive, and selective analytical method for the determination of methamphetamine in an odor-adsorbent material (gauze) which was used to improve and standardize the training method used for drug-detection animals. High-performance liquid chromatography (HPLC) was performed using a Spherisorb ODS2 C18 column (200 mm × 4.6 mm, 5 μm), with a mobile phase consisting of a 0.25% methanol/triethylamine aqueous solution (V:V = 20:80), the pH of which was adjusted to 3.1 using glacial acetic acid, at a flow rate of 1.0 mL/min. The column temperature was 25 °C, and the detection of the analytes was performed at a wavelength of 260 nm. Methamphetamine showed good linearity (R2 = 0.9999) in the range of 4.2~83.2 mg/mL. The stability of the test material was good over 24 h. The precision of the method was good, with an average spiked recovery of 86.2% and an RSD of 2.9%. The methamphetamine content in the gauze sample was determined to be 7.8 ± 2.2 μg/sample. A high-performance liquid chromatography (HPLC) method was optimized and validated for the determination of methamphetamine in adsorbent materials (gauze). Validation data in terms of specificity, linearity, the limit of detection and the limit of quantification, reproducibility, precision, stability, and recovery indicated that the method is suitable for the routine analysis of methamphetamine in adsorbent materials (gauze) and provided a basis for training drug-detection animals.

Wearable Electrochemical Glove-Based Analytical Device (eGAD) for the Detection of Methamphetamine Employing Silver Nanoparticles

Illicit drug misuse has become a widespread issue that requires continuous drug monitoring and diagnosis. Wearable electrochemical drug detection devices possess the potential to function as potent screening instruments in the possession of law enforcement personnel, aiding in the fight against drug trafficking and facilitating forensic investigations conducted on site. These wearable sensors are promising alternatives to traditional detection methods. In this study, we present a novel wearable electrochemical glove-based analytical device (eGAD) designed especially for detecting the club drug, methamphetamine. To develop this sensor, we immobilized meth aptamer onto silver nanoparticle (AgNPs)-modified electrodes that were printed onto latex gloves. The characteristics of AgNPs, including their shape, size and purity were analysed using FTIR, SEM and UV vis spectrometry, confirming the successful synthesis. The developed sensor shows a 0.1 µg/mL limit of detection and 0.3 µg/mL limit of quantification with a linear concentration range of about 0.01-5 µg/mL and recovery percentages of approximately 102 and 103%, respectively. To demonstrate its applicability, we tested the developed wearable sensor by spiking various alcoholic and non-alcoholic drink samples. We found that the sensor remains effective for 60 days, making it a practical option with a reasonable shelf-life. The developed sensor offers several advantages, including its affordability, ease of handling and high sensitivity and selectivity. Its portable nature makes it an ideal tool for rapid detection of METH in beverages too.

Artificial intelligence reinforced upconversion nanoparticle-based lateral flow assay via transfer learning

The combination of upconverting nanoparticles (UCNPs) and immunochromatography has become a widely used and promising new detection technique for point-of-care testing (POCT). However, their low luminescence efficiency, non-specific adsorption, and image noise have always limited their progress toward practical applications. Recently, artificial intelligence (AI) has demonstrated powerful representational learning and generalization capabilities in computer vision. We report for the first time a combination of AI and upconversion nanoparticle-based lateral flow assays (UCNP-LFAs) for the quantitative detection of commercial internet of things (IoT) devices. This universal UCNPs quantitative detection strategy combines high accuracy, sensitivity, and applicability in the field detection environment. By using transfer learning to train AI models in a small self-built database, we not only significantly improved the accuracy and robustness of quantitative detection, but also efficiently solved the actual problems of data scarcity and low computing power of POCT equipment. Then, the trained AI model was deployed in IoT devices, whereby the detection process does not require detailed data preprocessing to achieve real-time inference of quantitative results. We validated the quantitative detection of two detectors using eight transfer learning models on a small dataset. The AI quickly provided ultra-high accuracy prediction results (some models could reach 100% accuracy) even when strong noise was added. Simultaneously, the high flexibility of this strategy promises to be a general quantitative detection method for optical biosensors. We believe that this strategy and device have a scientific significance in revolutionizing the existing POCT technology landscape and providing excellent commercial value in the in vitro diagnostics (IVD) industry.

Corona discharge ionization ion mobility spectrometry for ultra-trace determination of methamphetamine extracted from urine and plasma samples by dispersive liquid-liquid microextraction

In this work, dispersive liquid-liquid microextraction (DLLME) based on high-density extraction solvent was applied as a simple, fast and sensitive method for extraction and preconcentration of methamphetamine from human plasma and urine samples. The efficiency of positive corona discharge ionization ion mobility spectrometry was investigated for direct analysis of the extracted analyte. Effective parameters on the extraction efficiency, such as type and volume of the extraction and disperser solvents, centrifugation time, and sample solution pH were optimized. Trichloromethane and isopropanol were selected as the extracting and disperser solvents, respectively. Under the optimized conditions, the linear dynamic range (R² = 0.9969) was found to be 0.5-18 µg/L, and 0.15 µg/L was calculated as the limit of detection. The relative standard deviations of intra- and inter-day were obtained 4 and 10%, respectively, and finally, in the analysis of human plasma and urine samples, the extraction recovery was obtained 104%.

High sensitive electrochemical methamphetamine detection in serum and urine via atom transfer radical polymerization signal amplification

Herein we designed a highly sensitive and selective biosensor for methamphetamine (METH) detection based on aptamer recognition probe and atom transfer radical polymerization (ATRP) signal amplification strategy. In this experiment, METH aptamer and its complementary DNA strand were first attached to the electrode surface. In the presence of METH, the prioritized conjugation between METH and the aptamer will take one strand of DNA from the double-stranded DNA, so that the third segment of azide-modified DNA could be successfully modified onto the electrode surface. Through click chemistry and ATRP polymerization, the monomers with ferrocene were polymerized into a long chain, and the signal was amplified, then high-sensitivity detection of METH can be carried out. The result showed that the sensor could detect METH as low as 17 fM, which is about two orders of magnitude lower than that by traditional METH detection methods. Moreover, when different concentrations of METH were added to serum and urine, the recovery rate of the biosensor was as high as 93%. Therefore, using nucleic acid aptamer as capture probe and ATRP as signal amplification strategy can provide a promising application platform for sensitive detection of low concentration toxicants.

Application of Carbonic Nanosheets Based on Urea Precursors as Dispersive Solid Phase Extraction Adsorbent for Extraction of Methamphetamine from Urine Samples

Purpose: This paper established the application of synthesized graphitic carbon nitride nanosheets (GCNNs) as an influential dispersive solid phase extraction (DSPE) adsorbent in extracting methamphetamine from complicated urine media coupled with high performance liquid chromatography.

Methods: The graphitic carbon nitride nanosheets (GCNNs) was synthesized easily and applied as adsorbent in the extraction process. The effective extraction parameters were investigated by one-parameter-at-a-time. Under optimized conditions the method was validated.

Results: The calibration curve was plotted in the concentration range of 50-1500 ng/mL through the optimized conditions and the proposed method was validated. The method was used for the analysis of positive urine samples and showed satisfactory results with the average 99.7% relative recovery.

Conclusion: The results persuade the capability of this novel method in analyzing of the positive urine samples in diverse clinical and forensic laboratories.

Recent developments in sample preparation techniques combined with high-performance liquid chromatography: A critical review

This review article compares and contrasts sample preparation techniques coupled with high-performance liquid chromatography (HPLC) and describes applications developed in biomedical, forensics, and environmental/industrial hygiene in the last two decades. The proper sample preparation technique can offer valued data for a targeted application when coupled to HPLC and a suitable detector. Improvements in sample preparation techniques in the last two decades have resulted in efficient extraction, cleanup, and preconcentration in a single step, thus providing a pathway to tackle complex matrix applications. Applications such as biological therapeutics, proteomics, lipidomics, metabolomics, environmental/industrial hygiene, forensics, glycan cleanup, etc., have been significantly enhanced due to improved sample preparation techniques. This review looks at the early sample preparation techniques. Further, it describes eight sample preparation technique coupled to HPLC that has gained prominence in the last two decades. They are (1) solid-phase extraction (SPE), (2) liquid-liquid extraction (LLE), (3) gel permeation chromatography (GPC), (4) Quick Easy Cheap Effective Rugged, Safe (QuEChERS), (5) solid-phase microextraction (SPME), (6) ultrasonic-assisted solvent extraction (UASE), and (7) microwave-assisted solvent extraction (MWASE). SPE, LLE, GPC, QuEChERS, and SPME can be used offline and online with HPLC. UASE and MWASE can be used offline with HPLC but have also been combined with the online automated techniques of SPE, LLE, GPC, or QuEChERS for targeted analysis. Three application areas of biomedical, forensics, and environmental/industrial hygiene are reviewed for the eight sample preparation techniques. Three hundred and twenty references on the eight sample preparation techniques published over the last two decades (2001-2021) are provided. Other older references were included to illustrate the historical development of sample preparation techniques.

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.

Rapid Analysis of Four Amphetamines in Urine by Self-Made Pipette-Tip Solid-Phase Extraction Followed by GC-MS/MS

A simple and rapid pipette-tip solid-phase extraction (PT-SPE) procedure with derivatization prior to gas chromatography triple quadrupole mass spectrometry analysis is developed for the simultaneous determination of amphetamine (AMP), methamphetamine (MA), 3,4-methylenedioxyamphetamine (MDA) and 3,4-methylenedioxymethamphetamine (MDMA) in urine samples. The PT-SPE procedure using self-made sorbent could extract drugs within 6 min from 100-μL urine samples, requiring low solvent-consumption (<2.0 mL). Besides, the self-made pipette tip could be reused at least five times. Under optimized conditions, the recoveries of four amphetamines at spiked levels (low, medium and high) ranged from 87.7 to 110.4%, with relative standard deviations < 9.5%. The limit of detections and limit of quantifications for AMP, MA, MDA and MDMA were in the range of 2.52–8.25 ng⋅mL−1 and 8.4–27.5 ng⋅mL−1, respectively. Validation results show that the proposed method is suitable for the quantitation of amphetamines and has been successfully applied in the urine samples of suspected drug abusers.

Electrospun polyamide/graphene oxide/polypyrrole composite nanofibers: an efficient sorbent for headspace solid phase microextraction of methamphetamine in urine samples followed by GC-MS analysis

A novel polyamide/graphene oxide/polypyrrole nanofiber was fabricated with the aid of the electrospinning technique and applied in headspace solid phase microextraction.

Metal organic framework based carbon porous as an efficient dispersive solid phase extraction adsorbent for analysis of methamphetamine from urine matrix

Carboxylated carbon porous adsorbent was derived from zeolite imidazole framework (ZIF-8) via carbonization of ZIF-8 under a nitrogen atmosphere. The synthesized carboxylated adsorbent was fully characterized by various techniques including Fourier transform spectroscopy (FTIR), powder X-ray diffraction (XRD), scanning electron microscopy (SEM), and zeta potential analysis. The carboxylated adsorbent was applied as dispersive solid phase extraction (DSPE) adsorbent for efficient extraction of methamphetamine (MET) from biological urine samples. Several extraction parameters influencing the extraction efficiency were investigated and the calibration curve was plotted under optimized conditions in urine media. The method showed a good linearity in the range of 50-2500 ng/mL. The limit of detection (LOD) and limit of quantification (LOQ) was 10 and 35.80 ng/mL, respectively. A satisfactory analysis of the positive real samples with the recovery of 99.83% confirms the applicability of the proposed method in different clinical and forensic laboratories.

Rational design of an ionic liquid dispersive liquid–liquid micro-extraction method for the detection of organophosphorus pesticides

In this study, a functionalized ionic liquid (IL), [MimCH₂COOCH₃][NTf₂] was rationally designed and explored as an extraction solvent in dispersive liquid–liquid microextraction (DLLME) combined with ultra-high performance liquid chromatography (UHPLC) for the sensitive determination of organophosphorus pesticides (OPs).

Fast and easy extraction of antidepressants from whole blood using ionic liquids as extraction solvent

This study aims to prove that ionic liquids (ILs) can be used as extraction solvents in a liquid-liquid microextraction, coupled to LC-MS/MS, for the quantification of a large group of antidepressants in whole blood samples. The sample preparation procedure consisted of adding 1.0mL aqueous buffer pH 3.0 and 60µL of IL (1-butyl-3-methylimidazolium hexafluorophosphate) to 1.0mL whole blood. Subsequently, a 5-min rotary mixing step was performed followed by centrifugation. The lower IL phase was collected, diluted 1:10 in methanol and 10µL was injected into the LC-MS/MS. The following analytes were included in the full-quantitative method: agomelatine, amitriptyline, bupropion, clomipramine, dosulepin, doxepin, duloxetine, escitalopram, fluoxetine, imipramine, maprotiline, mianserin, mirtazapine, nortriptyline, paroxetine, reboxetine, trazodone and venlafaxine. Selectivity was checked for 10 different whole blood matrices. Additionally, possible interferences of deuterated standards or other antidepressants were evaluated. Overall, no interferences were found. For each analyte a matrix-matched calibration curve was constructed (7 levels, n = 6), covering therapeutic and low toxic concentrations. Accuracy and precision were evaluated over eight days, at three concentration levels (n = 2). Bias, repeatability and intermediate precision results met with the proposed validation criteria, except for fluvoxamine, which was therefore only included in the semi-quantitative method. LOQs were set at the lowest calibrator concentration and LOD values were - for most analytes - within a range of 1-2ng/mL. Recoveries (RE) and matrix effects (ME) were evaluated for five types of donor whole blood, at two concentration levels. RE values were within a range of 53.11-132.98%. ME values were within a range of 61.92-123.24%. In conclusion, this study proves the applicability of ILs as extraction solvents for a large group of antidepressants in complex whole blood matrices.

Salicylic acid determination in estuarine and riverine waters using hollow fiber liquid-phase microextraction and capillary zone electrophoresis

A low-cost methodology using hollow fiber liquid-phase microextraction (HF-LPME) and capillary zone electrophoresis (CZE) with UV-Vis detector was developed to analyze the salicylic acid (SA) in estuarine and riverine waters. The technique is easy-to-use and rapid, and demands little volume of organic solvent. The extraction was carried out using a polypropylene membrane supporting into octan-1-ol. HF-LPME under optimized conditions (donor solution sample pH 2, acceptor solution pH 14, sample volume 25 mL, fiber length 10 cm, acceptor volume 25 μL, extraction time 3 h and stirring speed 350 rpm) presented high enrichment factor (407 times) and good recovery in real water samples (from 88 to 110%). A limit of detection of 2.6 μg L^-1 was achieved using CZE with UV-Vis detector as quantification method. The method was applied to direct quantification of SA in environmental complex estuarine and riverine water matrices.