Rapid quantitation of three synthetic cathinones in urine by magnetic dispersive solid-phase extraction combined with DART-HRMS

Application of Magnetic Materials Combined with Echo® Mass Spectrometry System in Analysis of Illegal Drugs in Sewage

The aim of this study is to solve the problems of the complicated pretreatment and high analytical cost in the detection technology of trace drugs and their metabolites in municipal wastewater. A high-performance magnetic sorbent was fsynthesized for the enrichment of trace drugs and their metabolites in wastewater to develop a magnetic solid-phase extraction pretreatment combined with the acoustic ejection mass spectrometry (AEMS) analytical method. The magnetic nanospheres were successfully prepared by magnetic nanoparticles modified with divinylbenzene and vinylpyrrolidone. The results showed that the linear dynamic range of 17 drugs was 1-500 ng/mL, the recovery was 44-100%, the matrix effect was more than 51%, the quantification limit was 1-2 ng/mL, and the MS measurement was fast. It can be seen that the developed magnetic solid-phase extraction (MSPE) method is a good solution to the problems of the complicated pretreatment and analytical cost in the analysis of drugs in wastewater. The developed magnetic material and acoustic excitation pretreatment coupled with mass spectrometry analysis method can realize the low-cost, efficient enrichment, and fast analysis of different kinds of drug molecules in urban sewage.

Automatic MDSPE Combined with DART-HRMS for the Rapid Quantitation of 21 Synthetic Cathinones in Urine

A new, rapid, and automated method for the quantitation of 21 synthetic cathinones in urine was established using magnetic dispersive solid-phase extraction (MDSPE) in combination with direct analysis in real time-high-resolution mass spectrometry (DART-HRMS). Sample preparation and quantitation were verified by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Methcathinone-D3, α-PVP-D8, and proadifen (SKF525A) were used as internal standards. Magnetic HLB extractant and NaH2PO4/NaOH buffer (0.2 M, pH 7) were used in automatic MDSPE. All 21 synthetic cathinones could be detected and analyzed by DART-HRMS in under 1 min. It was proven that the linearities of 21 synthetic cathinones were suitable (R2 > 0.99) in the concentration ranges of 0.5-100 ng/mL or 1-100 ng/mL. The precision and accuracy values were all within ±15%, and the samples were stable under various conditions. The average time of each sample from preprocessing to completion of detection was approximately 2 min, allowing for rapid sample analysis. The relative error (RE) of the concentrations obtained by DART-HRMS and LC-MS/MS were within ±13.61%, and the linear coefficient (R) was 0.9964. The results of DART-HRMS and LC-MS/MS provided equivalent values at the 95% confidence level. In summary, a simple, fast, and convenient quantitation method via DART-HRMS was established. This application can be utilized to reduce backlogs and promote rapid case processing.

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.