scholarly journals Rapid Screening Method for New Psychoactive Substances of Forensic Interest: Electrochemistry and Analytical Determination of Phenethylamines Derivatives (NBOMe) via Cyclic and Differential Pulse Voltammetry

2017 ◽  
Vol 89 (3) ◽  
pp. 1445-1452 ◽  
Author(s):  
Ana Flávia B. Andrade ◽  
Samuel Kasahun Mamo ◽  
Jose Gonzalez-Rodriguez
2019 ◽  
Vol 16 (33) ◽  
pp. 206-224
Author(s):  
K. M. SHESTAKOVA ◽  
S. A. SAVCHUK ◽  
N. V. MESONZHNIK ◽  
A. V. KUHARENKO ◽  
S. A. APPOLONOVA

The ongoing appearance of new psychoactive substances on the black market of illegal drugs, as well as the lack of information on their influence on the human body, faces several challenges in their determination by standard analytical techniques. Moreover, the rapid metabolism of new psychoactive substances reveals in the absence of possibility in the identification of their native structures in biological fluids. This study presents a new screening method for determination 137 psychoactive substances including their metabolites. 'Dilute-and-shoot' method was chosen as the preferable sample preparation technique, and consisted of 1:5 dilution of urine specimens with the solution of acetonitrile and water (30:70) followed by electrospray ionization – liquid chromatography-tandem mass spectrometry analysis. The developed qualitative method was validated according to United Nations Office on Drugs and Crime requirements that included assessment of selectivity, limits of detection, precision, and stability. In addition, the presented method was tested on 50 certified positive urine specimens containing different drugs of abuse. The confirmatory analysis was performed using a high-resolution mass-spectrometry approach. The presented screening method provides the possibility of simultaneous determination of synthetic cannabinoids (96), opioid analgesics (16), stimulators (13), hallucinogens (5), benzodiazepines (5) and non-classified drugs (10) during one run. The validation assessments of the novel method have shown high rates of its specificity, selectivity, intra- and inter-day precision and stability with the limit of detection ranged from 1 to 5 ng?mL-1. At the same time, tests of 50 positive samples showed excellent applicability of the developed screening method for routine preliminary screening analysis in toxicological laboratories.


1986 ◽  
Vol 51 (11) ◽  
pp. 2466-2472 ◽  
Author(s):  
Jiří Barek ◽  
Antonín Berka ◽  
Ludmila Dempírová ◽  
Jiří Zima

Conditions were found for the determination of 6-mercaptopurine (I) and 6-thioguanine (II) by TAST polarography, differential pulse polarography and fast-scan differential pulse voltammetry at a hanging mercury drop electrode. The detection limits were 10-6, 8 . 10-8, and 6 . 10-8 mol l-1, respectively. A further lowering of the detection limit to 2 . 10-8 mol l-1 was attained by preliminary accumulation of the determined substances at the surface of a hanging mercury drop.


1991 ◽  
Vol 56 (3) ◽  
pp. 595-601 ◽  
Author(s):  
Jiří Barek ◽  
Gulamustafa Malik ◽  
Jiří Zima

Optimum conditions were found for the determination of 4-nitrobiphenyl by fast scan differential pulse voltammetry at a hanging mercury drop electrode in the concentration range 1 . 10-5 to 2 . 10-7 mol l-1. A further increase in sensitivity was attained by adsorptive accumulation of this substance on the surface of the working electrode, permitting determination in the concentration range (2 – 10) . 10-8 mol l-1 with one minute accumulation of the substance in unstirred solution or (2 – 10) . 10-9 mol l-1 with three-minute accumulation in stirred solution. Linear scan voltammetry can be used to determine 4-nitrobiphenyl in the concentration range (2 – 10) . 10-9 mol l-1 with five-minute accumulation in stirred solution, with the advantage of a smoother baseline and smaller interference from substances that yield only tensametric peaks.


2021 ◽  
Author(s):  
Yan Jin ◽  
Tong QI ◽  
Yuqing Ge ◽  
Jin Chen ◽  
Li juan Liang ◽  
...  

In this paper, ultrasensitive electrochemical determination of phosphate in water is achieved by hydrophilic TiO2 modified glassy carbon electrodes for the first time. Differential pulse voltammetry (DPV) method is proposed...


2017 ◽  
Vol 9 (37) ◽  
pp. 5449-5454 ◽  
Author(s):  
Min Wei ◽  
Shuo Feng

A signal-off aptasensor for OTA detection at an apt/cDNA/AuNPs/cPC/NH2–AuE electrode using methylene blue as an electrochemical probe.


2011 ◽  
Vol 76 (5) ◽  
pp. 383-397 ◽  
Author(s):  
Ferenc T. Pastor ◽  
Hana Dejmková ◽  
Jiří Zima ◽  
Jiří Barek

The possibility of determination of chloramphenicol by differential pulse voltammetry at four different carbon paste electrodes, in the full pH range (2–12) of Britton–Robinson (BR) buffer was investigated. Electrodes were prepared by mixing spectroscopic graphite powder or glassy carbon microbeads with mineral oil (Nujol) or tricresyl phosphate. Under optimal conditions (BR buffer pH 12, the electrode prepared from glassy carbon microbeads and tricresyl phosphate), linear calibration graph was obtained only in 10–5 M chloramphenicol concentration range. Determination of lower concentrations of chloramphenicol was complicated by irreproducible peak of oxygen from the carbon paste which overlapped with peak of chloramphenicol. Addition of sodium sulfite removed the oxygen peak without influence on the peak of chloramphenicol. Under optimal conditions (electrode paste made from glassy carbon microbeads, BR buffer pH 10 and 0.5 M sodium sulfite), straight calibration line was obtained in the 10–6 and 10–5 M chloramphenicol concentration range. Limit of determination was 5 × 10–7 mol/l.


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