Sensitive screening of abused drugs in dried blood samples using ultra-high-performance liquid chromatography-ion booster-quadrupole time-of-flight mass spectrometry

Detection of 26 Drugs of Abuse and Metabolites in Quantitative Dried Blood Spots by Liquid Chromatography-Mass Spectrometry

A method was developed for the determination of 26 drugs of abuse from different classes, including illicit drugs in quantitative dried blood spots (qDBSs), with the aim to provide a convenient method for drug testing by using only 10 μL of capillary blood. A satisfactory limit of quantification (LOQ) of 2.5 ng/mL for 9 of the compounds and 5 ng/mL for 17 of the compounds and a limit of detection (LOD) of 0.75 ng/mL for 9 of the compounds and 1.5 ng/mL for 17 of the compounds were achieved for all analytes. Reversed-phase liquid chromatography was applied on a C18 column coupled to MS, providing selective detections with both +ESI and -ESI modes. Extraction from the qDBS was performed using AcN-MeOH, 1:1 (v/v), with recovery ranging from 84.6% to 106%, while no significant effect of the hematocrit was observed. The studied drugs of abuse were found to be stable over five days under three different storage conditions (at ambient temperature 21 °C, at -20 °C, and at 35 °C), thus offering a highly attractive approach for drug screening by minimally invasive sampling for individuals that could find application in forensic toxicology analysis.

Evaluation of hemaPEN® sampling device for measurement of cocaine and metabolites in capillary blood by LC-MS/MS

Background: Dried blood spot sampling has been reported for on-site collection of specimens, but measurements are affected by blood hematocrit, and special handling is required, especially for forensic applications. The hemaPEN^® blood collection device was developed to produce spots with constant volume. Results: Linearity between 1 and 500 ng/ml was shown for cocaine and the metabolites benzoylecgonine and cocaethylene. The assay demonstrated acceptable precision and accuracy, and analytes were stable for 7 days when kept inside hemaPEN devices. Accuracy of the assay was affected by hematocrit but was within acceptable limits. Conclusion: Use of the hemaPEN, which retains dried blood within the device, could be advantageous for the quantification of illicit drugs in capillary blood compared with conventional dried blood spot collection.

Analysis of methamphetamine, methadone, tramadol, and buprenorphine in biological samples by ion mobility spectrometry after electromembrane extraction in tandem with slug flow microextraction

A novel tandem extraction method based on electromembrane extraction (EME) and slug flow microextraction (SFME) was developed for the extraction of some narcotics (methamphetamine, methadone, tramadol, and buprenorphine) from biological samples. The analytes were quantified by corona discharge-ion mobility spectrometry (CD-IMS). In this method, initially, analytes were extracted using an EME procedure (step-1). After that, the acceptor solution of the first step containing target analytes was applied in an SFME procedure (step-2) as a donor solution for further preconcentration. In the second step, analytes were extracted from an aqueous solution into an organic extractant. The optimum EME and SFME conditions were as follows: type of supported liquid membrane: 2-nitrophenyl octyl ether containing 10% v/v di-(2-ethylhexyl) phosphate, acceptor solution pH: 1.0, sample solution pH: 4.0, voltage: 248 V, extraction time: 17.5 min, tilting number of glass capillary tube: 10 times, type of the organic extractant: toluene, the concentration of NaOH solution: 400 mM. Under optimum extraction conditions, good linearity was obtained in the range of 0.50-750.0 ng/mL with coefficients of determination (r²) ≥ 0.991. The limits of detection and quantification were achieved in the range of 0.15-3.5 ng/mL and 0.50-12.0 ng/mL, respectively. The inter-day and intra-day precisions (n = 3) provided RSDs lower than 12.8% and 12.7%, respectively. Enrichment factors and extraction recoveries of the analytes were in the range of 255.7 to 505.4 and 37.6-78.3%, respectively. Comparing the EME/HPLC-UV with EME-SFME/CD-IMS showed that using the tandem extraction method improved the enrichment factors by more than 2.7 times and limits of detection and quantification by more than 15 times. Finally, this procedure was used to quantify target analytes in plasma and urine samples.

Dried matrix spots: an evolving trend in the toxicological field

Dried matrix spot (DMS) is a sampling technique, primarily used to analyze blood to diagnose metabolic diseases in newborns. As this technique has several advantages, DMS has started to be employed for other purposes using other biological matrices and increasingly in toxicology over the last decade. The aim of this work was to review the analytical methods using DMS which can be applied to drugs of abuse and which have been published since 2010. Three different databases were searched, using dried, spots, and drugs of abuse as the descriptors and using a snowball search. After applying the exclusion criteria, 39 papers remained. The most common publications were related to the use of blood, which corresponded to 77% of the papers, followed by urine and oral fluid, which corresponded to 13 and 10% of the papers, respectively. The selected studies covered different illicit drugs, sample sizes of 5 to 250 µL and spot sizes ranging from 3 to 18 mm in diameter. This review also examined the extraction techniques and the methods employed to analyze various biological matrices and drugs of abuse, mostly by liquid-extraction and liquid chromatography-tandem mass spectrometry. The benefits of DMS include: a simple sample pretreatment, better stability than liquid matrices, a simple extraction procedure, lower costs, and environmental benefits. DMS appears to be a promising technique in the field of toxicology and provides new perspectives for use in forensic laboratories.

Optimized and Validated DBS/MAE/LC–MS Method for Rapid Determination of Date-Rape Drugs and Cocaine in Human Blood Samples—A New Tool in Forensic Analysis

The aim of this work was to develop a new method for the determination of selected substances from the date-rape drugs group: ketamine, benzodiazepines and cocaine. The method is based on the dried blood spot method which seems to be a suitable tool in the analysis of tested substances. The extraction process based on microwave-assisted extraction was optimized to enable optimal conditions for the isolation of a wide range of analytes from blood samples collected on DBS cards. The extraction with ethyl acetate with a buffer of pH = 9 carried out at a temperature of 50 °C for 15 min ensured high extraction efficiency of the tested analytes. The optimized method was validated. Limits of detection (LOD = 4.38–21.1 ng/mL) and quantification (LOQ = 14.6–70.4 ng/mL), inter- and intra-day precision (CV = 1.37–13.4% and 3.39–14.8%, respectively), recovery (RE = 93.0–112.4%) and matrix effect (ME = 98.4–101.6%) were determined. The validation results indicate the possibility of using the proposed method in the analysis of real blood samples collected from victims of sexual assault.

A Colorimetric Membrane-Based Sensor with Improved Selectivity towards Amphetamine

Due to their simplicity, speed and low cost, chemical spot tests are increasingly demanded for the presumptive identification of illicit drugs in a variety of contexts such as point-of-care assistance or prosecution of drug trafficking. However, most of the colorimetric reactions used in these tests are, at best, drug class selective. Therefore, the development of tests based on chemical reactions with improved discrimination power is of great interest. In this work, we propose a new colorimetric assay for amphetamine (AMP) based on its reaction with solutions of alkaline gold bromide to form an insoluble yellow–orange derivative. The resulting suspensions are then filtered onto nylon membranes and the precipitate collected is used for the visual identification of AMP. The measurement of the absorbance of the membranes by diffuse reflectance spectroscopy also allows the quantification of AMP in a simple and rapid way, as demonstrated for different synthetic and drug street samples. On the basis of the results obtained, it was concluded that the proposed procedure is highly selective towards AMP, as this compound could be easily differentiated from other common drugs such as methamphetamine (MET), ephedrine (EPH), scopolamine (SCP) and cocaine (COC).

Dried matrix spots in forensic toxicology

Dried matrix spots (DMS) has gained the attention of different professionals in different fields, including toxicology. Investigations have been carried out in order to assess the potential of using DMS for the analysis of illicit substances, the main interest of forensic toxicologists. This technique uses minimal volumes of samples and solvents, resulting in simple and rapid extraction procedures. Furthermore, it has proved to increase analyte stability, improving storage and transportation. However, DMS presents some limitations: the hematocrit influencing accuracy and inconsistencies regarding the means of spotting samples and adding internal standard on paper. Thus, we provide an overview of analytical methodologies with forensic applications focusing on drugs of abuse and discussing the main particularities, limitations and achievements.

Study of Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD) extraction FROM dried oral fluid spots (DOFS) and LC-MS/MS detection

Background

Oral fluid is a widely studied matrix able to isolate the primary Cannabis constituent THC, facilitating its detection via mass spectrometry, and in most cases link these findings to recent drug use. As an alternative to liquid oral fluid, dried oral fluid spots (DOFS) is a simple and a low-cost sampling technique. It has shown improved stability compared to liquid samples, allowing for the possibility to preserve the specimens under various temperature and humidity conditions. The sampling strategy is straightforward and involves the application of a small quantity of oral fluid aliquot to a paper substrate that is set to air dry allowing for on-site collection at a large-scale demand. The goal of this study is to study THC and CBD extraction from DOFS, applying a previous established protocol for a LC–MS/MS qualitative method validation. Although other drugs of abuse have been included in DOFS methods, this is the first method validation including cannabinoids. An alternative oral fluid extraction method (WAX-S tips) is demonstrated to improve the recovery of the analytes.

Methods

A pool of blank oral fluid was used to prepare THC and CBD spiked DOFS samples for method validation and application. Spiked oral fluid was used to demonstrate WAX-S tips THC and CBD extraction. All samples were analyzed on a LC–MS/MS instrument.

Results

The qualitative method validation for THC and CBD confirmation in DOFS included method selectivity, matrix effects (< 20%), recovery (average of 25%), process efficiency (average of 21%), LOD (2 ng/mL for THC and 4 ng/mL for CBD), absence of carryover, and DOFS stability (70% in 35 days) as figures of merit. The method application in blindly prepared samples demonstrated the method capability to identify THC and CBD. WAX-S tips extraction showed an average of 91% recovery of THC and CBD from liquid oral fluid.

Conclusions

THC and CBD extraction from DOFS showed low recoveries. However, the LC–MS/MS qualitative confirmation of THC and CBD in DOFS could improve cannabinoids screening in oral fluid, as it shows adequate LOD and stability over time. This method has potential for assisting the screening of drivers under possible drug influence by facilitating sample transportation and temporary storage in dried spot form. Additional research is suggested for WAX-S tips extraction and quantitative method validation.

Presence of anthraquinone in coffee and tea samples. An improved methodology based on mass spectrometry and a pilot monitoring programme

Anthraquinone has been linked to potential adverse effects on human health and the environment. The most commonly employed methods for the analysis of coffee and tea cause the extraction of matrix interferents such as the methylxanthines caffeine and theobromine, which hinder the analysis of anthraquinone. A new manual extraction method - using ethyl acetate as the extraction solvent with a dispersive solid-phase extraction clean-up step based on primary-secondary amines - has been developed. The new developed method allows for the quantitation of anthraquinone at 5 μg kg^-1 concentration levels, four times lower than the current maximum residue limit for coffee and tea in the European Union (20 μg kg^-1). Alongside, a new automated extraction method has also been developed. Finally, a pilot monitoring programme of 90 coffee and tea samples from several countries within the European Union has been performed, in which anthraquinone has been detected in a concentration range of 5.1-18.8 μg kg^-1 in 32% of the monitored samples, below the current 20 μg kg^-1 maximum residue limit, and in 48% of the monitored tea samples, revealing the need for including anthraquinone in a more extensive monitoring programme of tea.

Determination of Antidepressants and Antipsychotics in Dried Blood Spots (DBSs) Collected from Post-Mortem Samples and Evaluation of the Stability over a Three-Month Period

An LC-MS/MS method for the identification and quantification of antidepressants and antipsychotics was developed on dried blood spots (DBSs). Moreover, analyte stability on DBSs within a 3-month period was monitored. Aliquots of 85 µL of blood from autopsy cases were pipetted onto DBS cards, which were dried and stored at room temperature. DBSs were analyzed in triplicate immediately, within the following 3 weeks, and after 3 months. For each analysis, a whole blood stain was extracted in phosphate buffer and purified using Solid Phase Extraction (SPE) cartridges in order to avoid matrix effects and injected in the LC-MS/MS system. Thirty-nine molecules were screened. Limits of detection (LODs) ranged between 0.1 and 3.2 ng/mL (g) and 0.1 and 5.2 ng/mL (g) for antidepressants and antipsychotics, respectively. Limits of quantification (LOQs) varied from 5 to 10.0 ng/mL for both. Sixteen cases among the 60 analyzed resulted positive for 17 different analytes; for 14 of these the method was fully validated. A general good agreement between the concentrations on DBSs and those measured in conventional blood samples (collected concurrently and stored at -20 °C) was observed. The degradation/enhancement percentage for most of the substances was lower than 20% within the 3-month period. Our results, obtained from real post-mortem cases, suggest that DBSs can be used for routine sample storage.

Determination of benzodiazepines in blood and in dried blood spots collected from post-mortem samples and evaluation of the stability over a three-month period

We successfully developed and validated an LC-MS/MS method for the identification of 27 and quantification of 9 benzodiazepines and metabolites in whole blood and DBSs. The results provided a good qualitative and quantitative correlation between DBSs stored at room temperature and whole blood stored at -20°C. A good stability for a three-month period was observed for most of the compounds detected in real post-mortem samples.

Development and Validation of a Method Using Dried Oral Fluid Spot to Determine Drugs of Abuse

A liquid chromatography-mass spectrometry method using dried oral fluid spots was developed and validated for the simultaneous quantification of cocaine, benzoylecgonine, cocaethylene, amphetamine, and 3,4-methylenedioxymethamphetamine. The oral fluid was applied to a Whatman 903 grade paper and submitted to a drying time of 2.5 h. The extraction procedure was optimized by chemometric approach using simplex centroid design. Spots were extracted with a mixture of acetonitrile, buffer, and methanol. Calibration curves covered a linear concentration range of 40-500 ng/mL. Validation parameters of linearity, precision, accuracy, selectivity, carryover, matrix effects, and stability were evaluated and showed satisfactory results. Spot homogeneity was also satisfactory, with less than 15% of deviation from nominal concentration. Spot volume did not influence accuracy when less than 100 μL of the sample was applied to the spot. The validation of the proposed method suggests a potential application in different scenarios in toxicology.

Determination of Fentanyl Analog Exposure Using Dried Blood Spots with LC-MS-MS

Fentanyl, and the numerous drugs derived from it, are contributing to the opioid overdose epidemic currently underway in the USA. To identify human exposure to these growing public health threats, an LC-MS-MS method for 5 μL dried blood spots (DBS) was developed. This method was developed to detect exposure to 3-methylfentanyl, alfentanil, α-methylfentanyl, carfentanil, fentanyl, lofentanil, sufentanil, norcarfentanil, norfentanyl, norlofentanil, norsufentanil, and using a separate LC-MS-MS injection, cyclopropylfentanyl, acrylfentanyl, 2-furanylfentanyl, isobutyrylfentanyl, ocfentanil and methoxyacetylfentanyl. Preparation of materials into groups of compounds was used to accommodate an ever increasing need to incorporate newly identified fentanyls. This protocol was validated within a linear range of 1.00-100 ng/mL, with precision ≤12% CV and accuracy ≥93%, as reported for the pooled blood QC samples, and limits of detection as low as 0.10 ng/mL. The use of DBS to assess fentanyl analog exposures can facilitate rapid sample collection, transport, and preparation for analysis that could enhance surveillance and response efforts in the ongoing opioid overdose epidemic.

Green sample preparations for the bioanalysis of drugs of abuse in complex matrices

The sample preparation is the most critical step involved in the bioanalytical process. When dealing with green analytical chemistry, sample preparation can be even more challenging. To fit the green analytical chemistry principles, efforts should be made toward the elimination or reduction of the use of toxic reagents and solvents, minimization of energy consumption and increased operator safety. The simplest sample preparations are more appropriate for liquid biological matrices with little interfering compounds such as urine, plasma and oral fluid. The same does not usually occur with complex matrices that require more laborious procedures. The present review discusses green analytical approaches for the analyses of drugs of abuse in complex biological matrices, such as whole blood, breast milk, meconium and hair.