Bioanalytical LC-QTOF/MS Method for a N-phenylpiperazine Derivate (LQFM05): An Anxiolytic- and Antidepressant-like Prototype Drug Applied to Pharmacokinetic and Biodistribution Studies.

The LQFM05 is a prototype drug designed for treatment of psychiatric disorders, such as schizophrenia, exhibiting anxiolytic- and antidepressant-like (12 or 24 µmol/kg) effects in classical behavioral tests. In order to evaluate its pharmacokinetic properties, a liquid chromatography method coupled to a quadrupole time of flight mass spectrometry system (LC-QTOF/MS) was developed and fully validated for LQFM05 analysis in rat plasma and tissue samples (brain, heart, liver, and kidneys). Liquid-liquid extraction, solid phase extraction and protein precipitation were assessed as clean-up procedures for biological samples and analyte enrichment. Plasma and tissue samples underwent protein precipitation as a preliminary step, using acetonitrile. Linearity was fully demonstrated for the dynamic range (10.0 to 900.0 ng/mL), with r2 values higher than 0.99 (RSDslope ≤ 2%, Fcal < Ftab, Ccal < Ctab). Biodistribution studies in rats revealed high brain tissue concentrations (12.4 µg/g), suggesting elevated drug affinity to the main therapeutic target tissue, showing a blood partition coefficient of 1.9. Kidneys also showed great exposure and tissue affinity, suggesting a potential extrahepatic clearance. Likewise, all examined tissues exhibited satisfactory LQFMF05 distribution. The mass fragmentation spectrum indicated the presence of its main metabolite, LQFM235, yielded by high hepatic hydroxylation route, an equally bioactive derivative. Lastly, the developed LC-QTOF/MS method was shown to be sensitive (LOQ = 10 ng/mL), precise and accurate for LQFM05 determination in tissue homogenates and plasma samples.

Multielement determination (essential and potentially toxic elements) in eye shadows exposed to consumption in Brazil using ICP OES.

Worldwide, cosmetics (especially eye shadows) are widely consumed and have a great impact on the economy. The aim of this study was to determine the multielement composition, focusing on essential and potentially toxic elements, in cosmetics (eye shadow) exposed to consumption in Brazil. Concentrations of 17 elements (Al, As, Ba, Cd, Co, Cr, Cu, Mn, Mo, Ni, Pb, Sb, Se, Sr, Ti, V and Zn) were determined in samples (produced in China and Brazil) using a sequential optical emission spectrometer with inductively coupled plasma (ICP OES) after acid digestion, assisted by a closed digester block (6 mL of HNO3 + 2 mL of H2O2 + 1 mL of Triton ×-100 + 1 mL of ultrapure water). The method was validated by linearity, precision, accuracy, limits of detection (LoD) and quantification (LoQ). The elements were quantified (in µg g-1): Al (852-21,900), Ba (3.47-104), Cd (1.70-6.93), Cr (< 8.53-66.6), Cu (< 0.480-14.5), Mn (92.20-1,190), Ni (< 4.23-40.7), Pb (< 2.16-5.06), Sb (1.10-10.5), Sr (0.760-46.0), Ti (32.0-440), V (< 0.85-1.7) and Zn (24.90-2,600). As, Co, Mo and Se in all the investigated samples were found to be below the LoQ values of ICP OES. In this study, regardless of sample compositions and origins (Brazilian or Chinese), high levels of Al, Cd, Cr, Cu, Mn, Ni, Pb, Sb, Ti, V and Zn were observed, exceeding the recommended maximum tolerable limits, according to Brazilian and global legislations, which may present potential risks to human health and the environment.

A fast, low-cost, sensitive, selective, and non-laborious method based on functionalized magnetic nanoparticles, magnetic solid-phase extraction, and fluorescent carbon dots for the fluorimetric determination of copper in wines without prior sample treatment.

A new fluorimetric method for copper(II) determination in wines was developed combining functionalized magnetic nanoparticles (FMNP) and fluorescent carbon dots (FCD). To produce FMNP, Fe3O4 was coated with Al2O3 forming Fe3O4@Al2O3 core-shell magnetic nanoparticles and functionalized with PAN and SDS. FCD was synthesized from pineapple juice through hydrothermal carbonization. For copper determination, aliquots of wine, the FMNP dispersion, and Britton-Robinson buffer (pH = 4.0) were mixed under stirring to allow the adsorption of copper by FMNP. Cu-FMNP complex was attracted by a niobium magnet and, after discarding the non-magnetic material, the copper(II) ions were eluted with an FCD dispersion before fluorescence quenching measurements. The proposed method presented a linear range from 0.020 to 0.100 mg L-1 (r2 = 0.9953), RSD (intraday) < 3.0%, and recovery rates from 96 to 105 %. FMNP and FCD properties permitted extraction/preconcentration/determination of copper within 1 min with an enrichment factor of nine and without prior sample treatment.