Cathinones in urine samples: A review of recent advances for their determination by chromatographic and related techniques

Analysis of 15 anti-obesity drugs in urine using thermal-assisted paper spray mass spectrometry

Anti-obesity drugs, used to suppress appetite and reduce fat absorption, have been circulated and traded illegally worldwide. The traditional methods of liquid chromatography tandem mass spectrometry (LC-MS/MS) and gas chromatography-mass spectrometry (GC-MS) for analyzing these drugs in in vivo samples require complex sample pretreatment and time-consuming procedures. To address this issue, a thermal-assisted paper spray mass spectrometry (PS-MS) method was developed in this study to analyze anti-obesity drugs in raw urine. By incorporating a heat source and optimizing the spray solvent and paper substrate, this technique demonstrates reduced matrix effect and higher sensitivity compared to traditional PS-MS methodology for direct analysis of anti-obesity drugs in urine samples. A temperature range of 100-200 °C can be set for screening anti-obesity drugs in urine samples, with the flexibility to adjust the temperature according to the specific drug being analyzed. The limits of detection (LODs) for these 15 anti-obesity drugs in urine ranged between 1 and 500 ng mL-1. Furthermore, the thermal-assisted PS-MS method exhibited good linearities (R2, 0.9903-0.9997) within the range from 10-100 to 1000 ng mL-1 for the direct quantitation of anti-obesity drugs in urine samples with an internal standard. Therefore, the thermal-assisted PS-MS technique may provide a novel approach for the direct analysis of drugs in complex samples.

Development of a Liquid Chromatography-Tandem Mass Spectrometry Method for the Simultaneous Determination of 40 Drugs of Abuse in Human Urine: Application to Real Cases

Drugs of abuse are constantly evolving, while new synthetized substances are constantly emerging to avoid regulations. However, traditional drugs such as cocaine and amphetamine are still two of the most consumed drugs in the world. It is important, therefore, to provide suitable multiresidue methods for determining a wide range of drugs for use in toxicological and forensic analyses. The aim of this study is to develop a method for determining several families of drugs of abuse, including classic drugs, new psychoactive substances and some of their metabolites, in urine by liquid chromatography-tandem mass spectrometry. Urine is one of the most common biological matrices used in drug analysis because of its easy collection and a wide window of detection. In this study, we used solid-phase extraction to remove interferences and extract analytes from urine. Four different mixed-mode cation-exchange commercial sorbents were evaluated. The best results, in terms of apparent recoveries, were achieved with one of the strong cationic sorbents, ExtraBond SCX. The method achieved detection limits from 0.003 to 0.500 ng/mL and quantification limits from 0.050 to 1.500 ng/mL, which are suitable for determining these compounds at the usual levels found in the urine of drug users. The applicability of this method was demonstrated by analyzing real urine specimens from women following a detoxification program. Our results showed that the drug most consumed was cocaine, since it was detected in most urine specimens together with its main metabolite, benzoylecgonine. The polyconsumption of drugs from different families was also observed in some urine samples analyzed.

Analytical Approaches for the Determination of Buprenorphine, Methadone and Their Metabolites in Biological Matrices

The abuse of buprenorphine and methadone has grown into a rising worldwide issue. After their consumption, buprenorphine, methadone and their metabolites can be found in the human organism. Due to the difficulty in the assessment of these compounds by routine drug screening, the importance of developing highly sensitive analytical approaches is undeniable. Liquid chromatography tandem mass spectrometry is the preferable technique for the determination of buprenorphine, methadone and their metabolites in biological matrices including urine, plasma, nails or oral fluids. This research aims to review a critical discussion of the latest trends for the monitoring of buprenorphine, methadone and their metabolites in various biological specimens.

Application of a novel nylon needle filter-based solid-phase extraction device to determination of 1-hydroxypyrene in urine

In this work, a simple and miniaturized solid-phase extraction device was constructed by connecting a commercial nylon needle filter to a syringe, which was applied for extracting 1-hydroxypyrene from urine sample via hydrophobic and hydrogen bond interactions. The nylon membrane in the needle filter acted as the solid-phase extraction adsorbent, meanwhile, it filtered the particles in the urine sample. To obtain high extraction efficiency, key parameters influencing extraction recovery were investigated. The entire pretreatment process was accomplished within 5 min under the optimal conditions. By coupling HPLC-UV, a rapid, low-cost, and convenient nylon needle filter-based method was established for the analysis of 1-hydroxypyrene in complex urine matrix. Within the linearity range of 0.2-1000 μg/L, the method exhibited a satisfactory correlation coefficient (R = 0.9999). The limit of detection was 0.06 μg/L, and the recoveries from urine sample spiked with three concentrations (5, 20, and 100 μg/L) ranged from 105.8% to 113.1% with the relative standard deviations less than 6.7% (intra-day, n = 6) and 8.9% (inter-day, n = 4). Finally, the proposed method was successfully applied for detecting 1-hydroxypyrene in urine samples from college students, smokers, gas station workers, and chip factory workers. The detected concentration in actual urine samples ranged from 0.46 to 5.26 μg/L. Taken together, this simple and cost-effective nylon needle filter-based solid-phase extraction device showed an excellent application potential for pretreating hydrophobic analytes from aqueous samples. This article is protected by copyright. All rights reserved.

Simultaneous Determination of 16 Kinds of Synthetic Cathinones in Human Urine Using a Magnetic Nanoparticle Solid-Phase Extraction Combined with Gas Chromatography-Mass Spectrometry

A specific and sensitive approach using magnetic nanoparticle solid-phase extraction combined with gas chromatography-mass spectrometry (GC-MS) was carried out and applied in the simultaneous determination of 16 kinds of synthetic cathinones in human urine. The functionalized extraction material (Fe3O4/NH2-MWCNTs) was synthesized and factors affecting the extraction efficiency were all tested. Under the optimized conditions of magnetic nanoparticle solid-phase extraction, the determination of synthetic cathinones in human urine was carried out with GC-MS. Good linear relationships of 16 kinds of synthetic cathinones were obtained in the range of 0.005–5.00 μg/mL with the correlation coefficients (r) ranging from 0.9901 to 0.9979, the limits of detection were in the range between 0.005 and 0.01 μg/mL, and the limits of quantitation were between 0.01 and 0.02 μg/mL. Furthermore, the average intra-day precisions were below 8.90%, the average inter-day precisions were less than 9.52%, and the average recoveries were between 87.03% and 99.13%, respectively. The results show the advantages of the approach in the determination of trace synthetic cathinones in complex matrixes, such as environmentally friendly, fast detection, high efficiency and sensitivity. The practical application indicated that this method could provide scientific basis for the determination of drugs of abuse in forensic laboratories.