GC-MS/MS Determination of Synthetic Cathinones: 4-chloromethcathinone, N-ethyl Pentedrone, and N-ethyl Hexedrone in Oral Fluid and Sweat of Consumers under Controlled Administration: Pilot Study

This study presents a validated GC-MS/MS method for the detection and quantification of 4-chloromethcathinone or clephedrone (4-CMC), N-ethyl Pentedrone (NEP), and N-ethyl Hexedrone (NEH, also named HEXEN) in oral fluid and sweat and verifies its feasibility in determining human oral fluid concentrations and pharmacokinetics following the administration of 100 mg of 4-CMC orally and 30 mg of NEP and NEH intranasally. A total of 48 oral fluid and 12 sweat samples were collected from six consumers. After the addition of 5 μL of methylone-d₃ and 200 μL of 0.5 M ammonium hydrogen carbonate, an L/L extraction was carried out using ethyl acetate. The samples, dried under a nitrogen flow, were then derivatized with pentafluoropropionic anhydride and dried again. One microliter of the sample reconstituted in 50 μL of ethyl acetate was injected into GC-MS/MS. The method was fully validated according to international guidelines. Our results showed how, in oral fluid, the two cathinones taken intranasally were absorbed very rapidly, within the first hour, when compared with the 4-CMC which reached its maximum concentration peak in the first three hours. We observed that these cathinones were excreted in sweat in an amount equivalent to approximately 0.3% of the administered dose for 4-CMC and NEP. The total NEH excreted in sweat 4 h after administration was approximately 0.2% of the administered dose. Our results provide, for the first time, preliminary information about the disposition of these synthetic cathinones in the consumers' oral fluid and sweat after controlled administration.

Green Assessment of Chromatographic Methods Used for the Analysis of Four Methamphetamine Combinations with Commonly Abused Drugs

Numerous agents with anxiolytic or stimulant effects have the potential to be overused, and their misuse is associated with serious side effects. In Saudi Arabia, the estimated percentage of Saudis who abuse drugs is around 7–8% and the age range is 12–22 years. Methamphetamine, captagon, tramadol, heroin, and cannabis/cannabinoids have been proven to be the most commonly abused drugs in Saudi Arabia, with methamphetamine being at the top of the list. The present study focuses on the chromatographic analytical methods used for the analysis of methamphetamine in combination with commonly abused drugs, aiming to point out the greenest among them. These mixtures have been chosen as they are analyzed periodically and frequently in criminal evidence and forensic medicine. Therefore, the chances of hazards for analysts and the environment are high if the mixtures are not handled appropriately. This study aims to compare 23 chromatographic methods used for the analysis of methamphetamine mixtures in four major combinations, and to assess their greenness by using three greenness assessment tools, namely, NEMI, ESA and AGREE, to recommend the greenest analytical method. The NEMI results were proven to have low discriminating abilities and, accordingly, the comparisons are based on ESA and AGREE scores. The analysis results show that the safest methods with the most eco-friendly results (based on ESA and AGREE) are the GC-MS method proposed by Mohammed et al. to analyze methamphetamine and captagon mixtures (ESA = 79 and AGREE = 0.57), the UHPLC–MS-MS method proposed by Busardò et al. to analyze methamphetamine and cannabis/cannabinoid mixtures (ESA = 78 and AGREE = 0.57), the LC-MS method proposed by Herrin et al. to analyze methamphetamine and tramadol mixtures (ESA = 81 and AGREE = 0.56), and the LC-MS method proposed by Postigo-et al to analyze methamphetamine and heroin mixtures (ESA = 76 and AGREE = 0.58).

A Fast Analytical Method for Determining Synthetic Cathinones in Oral Fluid by Liquid Chromatography-Tandem Mass Spectrometry

In this paper, we present a method for simultaneously determining 11 synthetic cathinones in oral fluid (OF) by liquid chromatography-tandem mass spectrometry. Synthetic cathinones, a wide variety of which are available on the market, are constantly evolving. It is therefore important to provide efficient methods for determining cathinones in different matrices. A common matrix for detecting recent drug intake is OF, which can easily be collected using one of numerous commercial devices. Most methods aimed at determining drugs in biological samples such as OF require labor-intensive and time-consuming sample-preparation steps. However, the pretreatment of complex samples is often a challenge in the development of a method. For this reason, in this paper, we present a simple, easy-to-handle alternative that uses a Salivette® device and pretreats the sample in the same device. Matrix-matched calibration curves were used to cover the concentration range at which these substances are usually present in the OF from drug consumers. The method detection limits ranged from 0.003 to 0.03 ng/g, and the method quantification limits were set at 0.075 ng/g. This is a simple, rapid and sensitive method with good potential for determining recent drug consumption in OF.

Development and validation of GC-MS method for determination of methcathinone and its main metabolite in mice plasma and brain tissue after SPE: Pharmacokinetic and distribution study

Only focusing on the plasma levels is inadequate for the full consideration of the physiological disposition of illicit drugs in vivo. Therefore, we conducted the inclusive study on the in vivo dynamic process of intraperitoneal administration of methcathinone (MET), a well-known member of the synthetic cathinone derivatives, which is structurally similar to amphetamine analogs. This study described a validated, selective and sensitive GC-MS method for the simultaneous quantification of MET and its main metabolite, ephedrine (EPD), in the plasma and brain tissue of mice, after solid phase extraction (SPE). Ephedrine-d3 was used as an internal standard (IS). The developed method was validated following US-FDA guidelines within a concentration range of 5-1000 ng/mL for both drugs (r2 > 0.998) in the mice plasma and brain. The recoveries of MET and EPD from the mice plasma and brain ranged from 108.5 to 112.1%. The intra- and inter-day RSDs were ≤ 11.0 %. The proposed method was applied, for the first time, to investigate the pharmacokinetic (PK) and distribution study of MET and EPD following intraperitoneal administration of MET (1.4 mg/kg) to Swiss albino mice. The results exhibited that the C_max and T_max of MET in mice plasma was 517.1 ng/mL and 15 min as compared to 3.6 ng/mL and 2 h of EPD. Moreover, MET rapidly passed the blood brain barrier with C_max of 1444.5 ng/mL achieved at 15 min, whereas, EPD monitored C_max of 43.6 ng/mL at 4 h in mice brain. The highest concentration of MET in the mice brain followed by plasma was reported, with a necessity to perform more detailed clinical investigations.

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.

Drug exposure during pregnancy: analytical methods and toxicological findings

Drug use during pregnancy constitutes a major preventable worldwide public health issue. Birth defects, growth retardation and neurodevelopmental disorders are associated with tobacco, alcohol or drugs of abuse exposure during pregnancy. Besides these adverse health effects, drug use during pregnancy also raises legal and social concerns. Identification and quantification of drug markers in maternal and newborn biological samples offers objective evidence of exposure and complements maternal questionnaires. We reviewed the most recent analytical methods for quantifying drugs of abuse, tobacco, alcohol and psychotropic drugs in maternal, newborn and maternal-fetal unit biological samples by gas and liquid chromatography coupled to mass spectrometry. In addition, manuscripts comparing the usefulness of different biological samples to detect drug exposure during pregnancy were reviewed.