Forensic Drug Analysis Research Articles

Recent applications of high-performance thin-layer chromatography (HPTLC) in forensic drug analysis

Recent applications of high-performance thin-layer chromatography (HPTLC) in forensic drug analysis

Low-frequency Raman spectrum of methamphetamine hydrochloride and its alterations induced by impurities

Methamphetamine is one of the most abused drugs worldwide. Forensic laboratories have developed various methods to analyze methamphetamine for identifying and comparing seizures. These methods basically focus on the physicochemical properties of the methamphetamine molecule. Because methamphetamine is commonly distributed in its hydrochloride salt form, information on the crystalline state of methamphetamine could give new insight for forensic drug analysis. To grasp this information, we applied low-frequency Raman spectroscopy to methamphetamine hydrochloride. A laboratory-built low-frequency Raman microspectrometer was used for measuring low-frequency Raman spectra of optically pure and racemic methamphetamine hydrochloride. A mixture of methamphetamine hydrochloride with dimethyl sulfone, which is frequently added as a diluent to illicit methamphetamines, was also measured. An ab initio calculation was performed to assign peaks in the low-frequency spectra. The phonon modes of methamphetamine hydrochloride, and their changes induced by impurities are discussed. To the best of our knowledge, this is the first reported application of low-frequency Raman spectroscopy technique to methamphetamine hydrochloride.

Identification of MDA in seized ecstasy-like samples using atmospheric solids analysis probe mass spectrometry and machine learning

In this study, a total of 64 samples of ecstasy tablets seized during operations conducted within the State of Rio Grande do Sul – Brazil in 2021–2022 were analyzed. The instrumental analysis was performed using the Radian ASAP MS instrument with a single quadrupole mass spectrometer and an Atmospheric Solids Analysis Probe (ASAP) interface. Data preprocessing was conducted using MATLAB to improve data quality for subsequent chemometric analyses. Classification models seeking to identify samples containing MDA (3,4-methylenedioxyamphetamine) were developed using Linear Discriminant Analysis (LDA) with variable selection through the genetic algorithm (GA), stepwise (SW), and successive projections algorithm (SPA). Additionally, Partial Least Squares Discriminant Analysis (PLS-DA) models were explored. The GA-LDA model achieved an accuracy of approximately 95% for both training and testing sets, demonstrating its effectiveness in distinguishing between sample classes. It selected only five variables during model building. The SW-LDA model displayed exceptional performance in the training set, achieving 100% for all metrics. However, its accuracy for the testing set was slightly lower at 84.7%, suggesting potential overfitting due to the inclusion of numerous variables. The SPA-LDA model, while not the best performer in the testing set, selected variables that were more easily attributed to specific ions/fragments, aiding in the interpretation of results. Interpretation of selected variables revealed key m/z values associated with different compounds found in the samples, such as MDMA, cocaine, and amphetamine-related fragments. Notably, the SPA method selected six variables that played a crucial role in distinguishing between sample groups. These findings contribute to the advancement of forensic drug analysis and quality control processes.

Optimization and Evaluation of Column Efficiency in RP-HPLC Method for Pharmaceutical and Forensic Drug Analysis

Reverse Phase High Performance Liquid Chromatography (RP-HPLC) is an efficient and reliable technique employed in pharmaceutical and forensic analysis. The assay determination in pharmaceutical and certain molecular detection is performed using this technique. Performance of chromatographic columns play a central role in development of more efficient separation methods. It is one of the main component of system suitability testing in a chromatographic system. The column efficiency can be assessed by using various traditional methods and reproducible results can be evaluated using liquid chromatography We studied the column efficiency using RP-HPLC technique for pharmaceutical drug product Aceclofenac in a validated method. Two mobile phases combinations Acetonitrile: Methanol (80:20 v/v) and Acetonitrile: Methanol: Ammonia (225:50:1 v/v) were compared on C-8 Lichrospher RP-HPLC column for Aceclofenac and three tablet samples (30 ppm). The height equivalent to theoretical plate (HETP) referred as direct measure of column efficiency produced efficient results (530-545 and 190-230) for respective mobile phases. The lower HEPT is an indication of efficient elution in second mobile phase. The change in polarity as per pKa of the analyte may enhance elution and resolution. helpful in method development for pharmaceutical and forensic drug analysis using liquid chromatography.

Forensic Drug Analysis

Abstract: Forensic toxicology is a gathering of related disciplines that cooperate to help distinguish and break down medications and toxins for clinical and legitimate use. Forensic drug analysis isn’t just used in the coroner’s office; Additionally, it can be used to identify drugs in hospitalized patients who were admitted following a suspected poisoning (emergency clinical toxicology), drug-facilitated crimes in which drugs are used to sedate or poison, drugs and driving, and drugs used in human performance (i.e., drugs in sport). Toxicology labs should be furnished with the right devices, be authorize, and have sufficient information to lead deliberate toxicological investigations of drugs of revenue and to offer the ensuing appropriate translations important for legal cases

Rapid enantiomeric analysis of zopiclone in serum by supercritical fluid chromatography-tandem mass spectrometry.

Zopiclone (ZOP) is a hypnotic drug prescribed to treat insomnia. Due to the chiral nature of ZOP, the psychologically active S-form and inactive R-form need to be determined enantiomerically in a forensic drug analysis. In the present study, a supercritical fluid chromatography (SFC) method was designed with a faster analysis ability than that of previously reported techniques. The SFC-tandem mass spectrometry (SFC-MS/MS) method was optimized using a column with a chiral polysaccharide stationary phase (Trefoil CEL2). ZOP was extracted from pooled human serum using solid-phase extraction (Oasis HLB) and analyzed. The developed SFC-MS/MS method achieved the baseline separation of S-ZOP and R-ZOP within 2 min. The fit-for-purpose method validation indicated that the optimized solid-phase extraction achieved near complete recovery and approximately 70% of the matrix effect. Both the retention time and peak area showed sufficient precision. The lower and upper limits of quantification (LOQ) were 5.7 × 10-2 ng/mL and 25 ng/mL for R-ZOP, and 5.2 × 10-2 ng/mL and 25 ng/mL for S-ZOP. The calibration line was linear in the range from lower LOQ to upper LOQ. The stability test indicated that ZOP in serum stored in a refrigerator (4°C) degraded and about 55% remained in 31 days. The quick analysis of the SFC-MS/MS method makes it a valid option for the enantiomeric analysis of ZOP.

Cadmium-free silica-encapsulated molecularly imprinted AuZnCeSeS quantum dots nanocomposite as an ultrasensitive fluorescence nanosensor for methamphetamine detection

One of the major challenges facing forensic drug analysis is the difficulty in detecting ultralow concentration of illicit drugs in biological matrices without the need for an extraction or a pre-treatment step. This work report on the development of a novel AuZnCeSeS quantum dots (QDs)-molecular imprinted polymer (MIP) nanocomposite fluorescent probe for methamphetamine (METH) recognition. Silica-coated AuZnCeSeS QDs were synthesized and characterized using spectrophotometric, spectroscopic and electron microscopy techniques. Via a free radical polymerization reaction, a thin layer of MIP shell with METH as the template was coated around the QDs surface leading to the formation of a QDs-MIP nanocomposite probe. The MIP coating passivated the QDs surface leading to radiative fluorescence enhancement of the bound QDs. Under optimum reaction conditions, METH was selectively and quantitatively detected via a fluorescence quenching reaction process. The unique selectivity of the nanoprobe for METH recognition showed clearly that METH was able to precisely re-bind to the MIP surface with size and shape reorganization. While the MIP shell functioned to provide the required selectivity, the AuZnCeSeS QDs functioned to fluorescently report the surface binding interaction. The use of a AuZnCeSeS QDs-non-imprinted polymer as probe to detect METH resulted in poor sensitivity and selectivity; hence, demonstrating the suitability of the AuZnCeSeS QDs-MIP nanoprobe to accurately detect METH. METH was detected within a wide concentration range from 0.05 to 50,000 nM with a detection limit of ∼0.02 nM (0.0036 ng/mL). The developed AuZnCeSeS QDs-MIP nanoprobe was efficiently used to detect METH in untreated urine sample with recovery efficiency from ∼100 to 110%.

Separation of Amphetamine from Captagon Tablets and Analysis by Fourier Transform Infrared Spectroscopy

Effective and rapid detection methods in the field of forensic drug analysis are crucial for reducing overall analysis time and improving reliability. The purpose of this study is to develop a simple and rapid method for the separation of amphetamine from captagon tablets and analysis by means of Fourier transform infrared spectroscopy (FTIR). In this study, the separation of amphetamine using a variety of solvents, including chloroform, Acetonitrile, dichloromethane, methanol and water, were studied. The results obtained show that the separation using a mix of acetonitrile (ACN) with methanol (MeOH) gives a matching percentage close to 97.14% of amphetamine sulfate when compared with the IR spectrum given in the reference (SWGDRUG) library. This method can be used as a confirmatory test for positive results within minutes without false positives.

Gas Chromatography—High-Temperature Proton-Transfer Reaction Mass Spectrometry as a Novel Tool for Forensic Drug Testing

Proton-transfer reaction mass spectrometry (PTR-MS) is a versatile tool for the mass spectrometric analysis of organic molecules in gaseous samples. Due to its operation principle, PTR-MS is a soft ionization technique generating spectral data typically rich in protonated molecule information. Most of the currently reported PTR-MS applications are designed to determine volatile compounds. Herein, we present a redesigned instrumental setup termed “high-temperature (HT)-PTR-MS” with improved capabilities for the analysis of low-volatile compounds. The developed HT-PTR-MS prototype was successfully hyphenated with gas chromatography (GC) to enable qualitative and quantitative analysis of licit and illicit drugs in human blood/plasma samples. Different kinds of spiked and authentic samples were used to evaluate the performance of the GC-HT-PTR-MS in forensic drug testing. Benchmarking against GC-MS with electron ionization demonstrated the improved detection capabilities of GC-HT-PTR-MS in screening applications. On average, one order of magnitude lower limits of detection/identification were reached. Clearly, GC-HT-PTR-MS has the vast potential to complement or even replace established mass spectrometric techniques in forensic drug analysis.

Deliberate evasion of narcotic legislation: Trends visualized in commercial mixtures of new psychoactive substances analyzed by GC-solid deposition-FTIR

List-based approaches for judicial control of synthetic drugs inevitably introduce a group of legal highs that do not fall under the scope of legislation but may exhibit similar effects and associated health risks as illicit substances. Differences between controlled and uncontrolled components may be as minor as a single molecular group rearrangement. This phenomenon complicated forensic drug analysis in recent years due to both the rise of new psychoactive substances (NPS), and selectivity limitations of the workhorse gas chromatography-mass spectrometry (GC−MS) technique, especially with respect to ring-isomers. Our study demonstrates the value of GC-solid deposition-Fourier-transform infrared spectroscopy (FTIR) as a complementary technique for NPS identification in multi-drug mixtures. The instrument design using direct deposition of the GC effluent on a cryogenically cooled ZnSe-disk allows for signal enhancement of minor constituents by collecting eluting peaks of multiple GC injections. Highly diagnostic spectra were obtained for all ortho, meta and para-isomers of fluoroamphetamine (FA), fluoromethamphetamine (FMA), methylmethcathinone (MMC) and methylethcathinone (MEC). Combined results of GC−MS and GC-solid deposition-FTIR revealed the presence of up to 11 individual NPS mixed together in liquid samples sold as research chemicals or room odorizer in The Netherlands. Sample compositions rapidly evolved over time with recently controlled substances such as 4-fluoroamphetamine (4-FA), pentedrone, ethylone and 4-methylethcathinone (4-MEC) being replaced by uncontrolled isomers or analogues as 2-fluoroamphetamine (2-FA), 2- or 4-fluoromethamphetamine (2-FMA, 4-FMA) and dimethylone. In 12 different samples all marketed under two brand names, a total of 9 different compositions were identified in samples from 2018 and 2019.

Gas chromatography with dual cold electron ionization mass spectrometry and vacuum ultraviolet detection for the analysis of phenylethylamine analogues

Identification of phenethylamine (PEA) analogues is of great importance and requires analytical methods of high specificity. Forensic drug analysis is often performed by gas chromatography (GC) most commonly coupled with mass spectrometric (MS) detection. However, analysis of labile compounds is problematic with classical electron ionization (EI)-MS, and positional isomers may be difficult to differentiate by MS. Cold electron ionization (cold EI) improves molecular ion relative intensity by reducing the analyte vibrational energy prior to ionization. Vacuum ultraviolet (VUV) is a gas phase technique that can provide complementary selectivity to MS for identification. In this study, cold EI-MS was used in parallel with VUV detection for the analysis of select PEA analogues and positional isomers. Molecular ion relative intensity was increased for nearly all compounds included in this study. Principal component analysis demonstrated that VUV is more successful at distinguishing between positional isomers than MS. A library database of VUV spectra was set up to identify compounds, which was later used to deconvolute spectra of coeluting compounds. Detection limits for VUV are lower than those of MS with cold-EI, where VUV is capable of reaching sub-microgram per milliliter levels. Linearity tests on VUV showed high correlation coefficients (R2 > 0.999) for close to or over and order-of-magnitude dynamic range.

Optimization of the qualitative and quantitative analysis of cocaine and other drugs of abuse via gas chromatography – Vacuum ultraviolet spectrophotometry (GC – VUV)

Gas Chromatography-Vacuum UV Spectroscopy (GC-VUV) has seen increased attention in many areas, however, a statistical optimization of VUV method parameters has not been published. This article presents the first statistical optimization of parameters influencing analytes such as cocaine in the VUV flow-cell. Flow-cell temperature, make-up gas pressure, and carrier gas flow rate from the GC were examined and optimized for the detection of controlled substances. The accuracy, precision, linearity, and optimized detection limits for drugs such as cocaine (98.5%, 1.2%, 0.9998, 1.5 ng), heroin (99.3%, 0.94%, 0.9998, 2.0 ng), and fentanyl (98.5%, 1.7%, 0.9752, 9.7 ng) are reported. In general, the limits of detection for cocaine, heroin, fentanyl, and methamphetamine after optimization were comparable to gas chromatography-mass spectrometry (GC-MS) in “scan mode”, which had detection limits of 1.1–38 ng on column. The VUV absorption spectra of cocaine, PCP, lorazepam, and HU-210 are also reported. And three samples of “real world” cocaine are analyzed to demonstrate applicability to forensic drug analysis.

Differentiation of ring-substituted regioisomers of cathinone analogs by supercritical fluid chromatography.

Various new psychoactive substances, such as cathinone and its analogs, possess similar chemical structures. Accurate identification of structurally similar drugs of abuse is important in forensic drug analysis. Chromatographic differentiation is a powerful analytical technique for this purpose. In this study, we applied supercritical fluid chromatography to differentiate ring-substituted regioisomers of six synthetic cathinone analogs (fluoro-α-pyrrolidinovalerophenone, methyl-α-pyrrolidinovalerophenone, methoxy-α-pyrrolidinovalerophenone, fluoro-α-pyrrolidinooctanophenone, fluoropentedrone, and fluorooctedrone). The examined cathinone analogs were weakly retained on the stationary phase (possessing diol functional group) and eluted quickly. We optimized the conditions to retain the examined cathinone analogs to achieve sufficient separation, and found that the types of functional groups on the stationary phase greatly affected the retention and separation. Systematic examination of the chromatographic conditions showed that the two stationary phases possessing anthracene and pentafluorobenzyl groups had good separation capabilities for the examined 2-, 3-, and 4-regioisomers of six cathinone analogs, which had different skeletal structures. Interestingly, the two stationary phases showed different selectivities, and alteration of the elution order was observed. The developed method was validated and its discrimination ability was investigated by measuring mass spectra and absorption spectra. Supercritical fluid chromatography-ultraviolet absorption spectroscopy/mass spectrometry is a powerful analytical technique for differentiation of ring-substituted cathinone analogs.

A Bottom-Up Approach for Developing Aptasensors for Abused Drugs: Biosensors in Forensics.

Aptamer-based point-of-care (POC) diagnostics platforms may be of substantial benefit in forensic analysis as they provide rapid, sensitive, user-friendly, and selective analysis tools for detection. Aptasensors have not yet been adapted commercially. However, the significance of the applications of aptasensors in the literature exceeded their potential. Herein, in this review, a bottom-up approach is followed to describe the aptasensor development and application procedure, starting from the synthesis of the corresponding aptamer sequence for the selected analyte to creating a smart surface for the sensitive detection of the molecule of interest. Optical and electrochemical biosensing platforms, which are designed with aptamers as recognition molecules, detecting abused drugs are critically reviewed, and existing and possible applications of different designs are discussed. Several potential disciplines in which aptamer-based biosensing technology can be of greatest value, including forensic drug analysis and biological evidence, are then highlighted to encourage researchers to focus on developing aptasensors in these specific areas.

Detection of the recently emerged synthetic cannabinoid 4F-MDMB-BINACA in "legal high" products and human urine specimens.

Synthetic cannabinoids (SCs) remain one of the largest groups of new psychoactive substances (NPS) on the European drug market. Although the number of new derivatives occurring on the market has dropped in the last two years, newly emerging NPS still represent a challenge for laboratories performing forensic drug analysis in biological matrices. The newly emerged SC 4F-MDMB-BINACA has been reported by several law enforcement agencies in Europe and the USA since November 2018. This work aimed at revealing urinary markers to prove uptake of 4F-MDMB-BINACA and differentiate from the use of structurally similar SCs. Phase-I metabolites detected in human urine specimens were confirmed by phase-I metabolites generated in vitro using a pooled human liver microsomes (pHLM) assay. Seized materials and test-purchased "legal high" products were analyzed by gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-quadrupole-time-of-flight-mass spectrometry (LC-qToF-MS). Human urine specimens and pHLM assay extracts were measured with liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) and confirmed by LC-qToF-MS. In January 2019, the Institute of Legal Medicine in Erlangen (Germany) identified 4F-MDMB-BINACA in three herbal blends. During the same time period, the described SC was identified in a research chemical purchased online. Investigation of phase-I metabolism led to the metabolites M10 (ester hydrolysis) and M11 (ester hydrolysis and dehydrogenation) as reliable urinary markers. Widespread distribution on the German drug market was proven by analysis of urine samples from abstinence control programs and by frequent detection of 4F-MDMB-BINACA in "herbal blends" and "'research chemicals" purchased via the Internet.

Differentiation of FUB-JWH-018 positional isomers by electrospray ionization–triple quadrupole mass spectrometry

Analytical differentiation of the positional isomers of synthetic cannabinoids (SCs) is a notable issue in forensic drug analysis, because only one or two of the imaginable isomers are controlled legally in most cases. Two series of fluorine-substituted SCs, differing in the substituent positions, were examined by electrospray ionization–triple quadrupole mass spectrometry (ESI-QqQ MS) to assess the capabilities of this technique to differentiate their positional isomers. The mass spectra of (1-(4-fluorobenzyl)-1H-indol-3-yl)(naphthalen-1-yl)methanone (FUB-JWH-018) and its positional isomers were recorded while the collision energy was varied (5–90 eV), and the fragment ions of the protonated precursor ions [M+H]+ were characterized. The applicability of ESI-QqQ MS in the positive mode was demonstrated by analyzing the naphthalen-2-yl derivative of FUB-JWH-018 and its positional isomers. The statistical analysis of the principal fragment ions in the 80 eV spectra of each synthetic cannabinoid allowed the authors to significantly differentiate its isomers based on their m/z (127:109) ratio.

Forensic drug analysis of chloro-N,N-dimethylcathinone (CDC) and chloroethcathinone (CEC): Identification of 4-CDC and 4-CEC in drug seizures and differentiation from their ring-substituted positional isomers

We report our findings for the determination of 4-chloro-N,N-dimethylcathinone (4-CDC), a newly encountered NPS in drug seizures examined in our laboratory, and its differentiation from 4-chloroethcathinone (4-CEC), one of the most common cathinones examined locally, and their respective regioisomers, namely 2-CDC and 3-CDC, as well as 2-CEC and 3-CEC in routine drug analysis.As CDCs and CECs have the same molecular mass of 211 with similar and non-characteristic spectra when analysed by gas chromatography-electron ionization-mass spectrometer (GC–EI-MS), it is imperative to establish methods easily amendable for forensic laboratories to differentiate these substances unambiguously. To confirm the identity of the solid, reference standards of all regioisomers of CDC (i.e., 2-CDC, 3-CDC and 4-CDC) and CEC (i.e., 2-CEC, 3-CEC and 4-CEC) were acquired and analysed using GC–EI-MS, liquid chromatography-diode array detector (LC–DAD) and Fourier Transform Infrared Spectrophotometer (FTIR) commonly used in routine forensic drug analysis. In addition, drug analysis with gas chromatography-chemical ionization-mass spectrometer (GC–CI-MS) using methane as the reagent gas operated in positive mode was also explored. It is found that using GC–EI-MS, all isomers of CDCs and CECs eluted with close but different retention times. However, the mass spectra between respective regioisomers were similar and difficult to distinguish. Using LC–DAD, the retention times of all studied cathinones were again different although there were partial overlap between 3-CDC and 4-CDC as well as between 3-CEC and 4-CEC but they all have distinguishable UV spectra. Apart from the detection of quasimolecular ion as the most prominent ion for each cathinone, GC–CI-MS is considered a superior technique to determine all six cathinones where each cathinone showed a unique fragmentation pattern for ease of identification. The analytical techniques have been applied for the examination of drug seizures where 4-CDC and 4-CEC were unambiguously identified either as a single component or mixed components in the seized materials.While FTIR is capable of providing confirmative structural information for the cathinones with each regioisomer exhibits a distinctive pattern but requiring high drug purity, LC–DAD and GC–CI-MS are demonstrated to be useful techniques that can readily differentiate structurally similar synthetic cathinones (even in mixtures) for routine forensic drug analysis.

Rapid detection of hypnotics using surface-enhanced Raman scattering based on gold nanoparticle co-aggregation in a wet system.

Sensitive detection of drugs using a method with high qualification capability is important for forensic drug analysis. Vibrational spectroscopy is a powerful screening technique because it can provide detailed structural information of the compounds included in samples with simple experimental protocols. Among various spectroscopic techniques, surface enhanced Raman scattering (SERS) spectroscopy has attracted enormous attention owing to its ultra-high sensitivity. In this study, we developed a method for rapid detection of hypnotics using SERS with gold nanoparticle co-aggregation in a wet system. The developed method required a simple analytical protocol. This enabled rapid analysis with high stability and repeatability. We analyzed various hypnotics (19 types including benzodiazepines and nonbenzodiazepines) to investigate the structure-spectrum relationship. As a proof of concept for application to real crime samples, simulated spiked beverages containing one hypnotic (etizolam, flunitrazepam, zolpidem, or zopiclone) were analyzed. Diluting the beverage samples decreased the matrix effect and allowed for detection of these hypnotics. Except for flunitrazepam, strong signals were observed for all hypnotics, and the estimated lower limit of detection was 50 ppm in apple drink. The developed approach is a rapid method for screening analysis of hypnotics with low sample requirements.

Differentiation of fentanyl analogues by low-field NMR spectroscopy

Forensic laboratories commonly receive new psychoactive substances such as fentanyl analogues and other synthetic opioids that are difficult to identify. Slight changes to chemical structures, e.g. shifting the position of functional groups such as methyl groups or halogens on the aromatic ring, may not be distinguished using traditional methods. NMR is a powerful tool used to elucidate distinctive structural information needed to differentiate regioisomers. However, the cost, size, and cryogen maintenance of superconducting NMR spectrometers can be impractical for some forensic laboratories. Recent studies have shown potential applications of low-field NMR as an alternative in forensic drug analysis. These benchtop, semi-portable instruments are less costly, have a smaller footprint, do not use cryogens, and require little maintenance. In this study, we show that 65 fentanyl and related substances, including various types of positional isomers, were readily differentiated using low-field (62 MHz) 1H NMR spectroscopy. In addition, the use of quantum mechanical spin system analysis was investigated for the purposes of translating experimentally observed high-field 1H spectra to lower field strengths. Spin system analysis of 600 MHz NMR spectra was conducted on a subset (15) of the reference materials analyzed. The results were used to calculate 62 MHz spectra for comparison purposes with the experimental spectra. This was successfully demonstrated, showing that field-strength independent 1H NMR spectral libraries are feasible and can facilitate reference material data dissemination across forensic drug laboratories.

Molecularly imprinted polymer solid‐phase extraction of synthetic cathinones from urine and whole blood samples

In forensic drug analysis, extractive pretreatment is required prior to instrumental analysis to ensure successful detection of the target compounds. However, conventional extraction methods such as hydrophilic polymer-based solid-phase extraction and liquid-liquid extraction are unsuitable for an emerging class of new psychoactive substances, namely, synthetic cathinones, because they exhibit a lack of class selectivity and increased risk of target analyte decomposition during extraction. To address these issues, we describe a highly class-selective sample clean-up method for the extraction of synthetic cathinones from urine and whole blood samples, exploiting a molecularly imprinted polymer solid-phase extraction cartridge. In terms of the influence of the synthetic cathinone molecular structure on the extraction recovery, we showed that while longer alkyl side chains slightly reduced the extraction efficiency, substituent variation on the aromatic ring exerted no effect. Molecularly imprinted polymer solid-phase extraction of 11 synthetic cathinones from urine samples yielded higher recoveries than the two conventional extraction methods, and smaller matrix effect was observed than that with hydrophilic polymer-based solid-phase extraction. Molecularly imprinted polymer solid-phase extraction from whole blood samples gave recoveries comparable to those of urine samples. Therefore, the proposed method is applicable for the extraction and quantitative determination of synthetic cathinones in biological samples.