Polyethyleneimine-modified porous aromatic framework and silane coupling agent grafted graphene oxide composite materials for determination of phenolic acids in Chinese Wolfberry drink by HPLC.

A simple method for the determination of phenolic acids in Chinese Wolfberry drink based on polyethyleneimine modified porous aromatic framework and graphene oxide composite sorbent for pipette-tip solid-phase extraction was developed. Porous aromatic framework and raphene oxide composite materials were grafted by silane coupling agent (3-Chloropropyl)-trimethoxysilane. The modified materials were characterized by five kinds of characterization. Experimental results showed that the prepared p-phenylenediamine, cyanuric chloride, and graphene oxide composite material had a loose structure combined with the framework which improved hydrophobicity, and polyethyleneimine to increase the selectivity with the targets. The parameters of the pipette-tip solid-phase extraction procedure including the amount of sorbents, volumes and types of washing solvents and elution solvents were optimized to achieve optimal extraction efficiency. Good linearity of best material was achieved in the range of 0.1-400 µg/mL with correlation coefficient of chlorogenic acid (0.9994), caffeic acid (0.9997), and ferulic acid (0.9998). Recoveries between 93.5 and 102.3% were obtained at three spiked levels with relative standard deviation ≤3.1%. The proposed method was successfully applied for the determination of phenolic acids in Chinese Wolfberry drink sample.

Synthesis and characterization of deep eutectic solvents (five hydrophilic and three hydrophobic), and hydrophobic application for microextraction of environmental water samples.

Hydrophilic and hydrophobic deep eutectic solvents (DESs) as "green" solvents were applied in this study for the microextraction of environmental samples. A series of DESs (five hydrophilic and three hydrophobic) were synthesized and characterized by Fourier transform infrared spectroscopy. Physicochemical property parameters of eight DESs including water solubility, density, conductivity, and freezing point were assessed. Compared with the performance of five hydrophilic DESs in water phase, the three hydrophobic DESs were more suitable for application in dispersive liquid-liquid microextraction for the determination of sulfonamides in water sample. In dispersive liquid-liquid microextraction process, analytical parameters including type and volume of extraction solvent, extraction time, and pH of water sample were investigated. Under optimum conditions, 60 µL of hydrophobic DESs was used for extraction for 2 min in pH = 7.0 sample. The linear ranges were 0.05-5.0 µg/mL for the four sulfonamides with the correlation coefficients in the range of 0.9991-0.9999. The limits of detection were in the range of 0.0005-0.0009 µg/mL and the limits of quantification were in the range of 0.0019-0.0033 µg/mL. The recoveries of the analytes of the proposed method for the spiked samples were 80.17-93.5%, with the relative standard deviation less than 6.31%. The results indicated that three hydrophobic DESs showed commendable performance for extraction of sulfonamides, and hydrophobic DES-based microextraction method was successfully applied for monitoring sulfonamides in water samples. Graphical abstract.

Acrylamide-Modified 3-Aminopropyltriethoxysilanes Hybrid Monomer for Highly Selective Imprinting Recognition of Theophylline.

The hybrid monomer synthesized with 3-aminopropyltriethoxysilanes and acrylamide was applied for synthesis of molecularly imprinting polymers, and the obtained polymers were used as sorbent in solid-phase extraction for purification of theophylline (THP) in green tea. The static adsorption curves showed better molecular recognition ability and binding capability of the polymers for the target. On the optimized condition, a method was developed for increasing extraction of THP with satisfactory recovery of 93.7%. Good calibration linearity obtained in a range of 5-500 µg·mL-1. The recoveries at three spiked levels ranged from 86.7% to 100.7% with relative standard deviations ≤6.6% (n = 3). The result showed that the obtained polymers exhibited highly selective imprinting recognition to the analyte, and the number of templates was an important factor affecting the selective recognition ability of polymers. The proposed method with hybrid monomer imprinting polymers was successfully applied for purification of THP in green tea.

CSF miR-16 is decreased in major depression patients and its neutralization in rats induces depression-like behaviors via a serotonin transmitter system.

BACKGROUND: Animal and cell line studies demonstrated that miR-16 may be associated with major depressive disorder (MDD) via regulation of the expression of serotonin transporter (SERT) gene. However, human studies about miR-16 of patients with MDD are still lacking. The aim of this study was to investigate the possible involvement of miR-16 in the mechanism of MDD in humans. METHODS: Thirty-six drug-free patients with MDD and 30 healthy controls aged between 18 and 45 years old were recruited. 24-item Hamilton depression scale test was performed for each subject. MiR-16 in cerebrospinal fluid (CSF) and blood, as well as serotonin in CSF were assayed by the qRT-PCR or ELISA method. To confirm the role of CSF miR-16 in MDD, animal study about intracerebroventricular injection of anti-miR-16 was also performed. Depression-like behaviors, CSF miR-16 and serotonin, blood miR-16, and raphe SERT protein of rats were also tested. RESULTS: CSF miR-16 in MDD patients was significantly lower than that in controls. It was negatively correlated with Hamilton scores and positively associated with CSF serotonin. However, blood miR-16 was not significantly different between two groups and it was not statistically correlated with CSF miR-16. In animal study, anti-miR-16-treated rats were evaluated to exhibit depression-like behaviors, extremely lower CSF miR-16, significantly higher CSF serotonin, and obviously higher raphe SERT protein than control rats. LIMITATION: We did not detect SERT protein in human brain due to the impossibility of sample collection. CONCLUSION: Our study suggested that CSF miR-16 participated in the physiopathology of MDD via the modulation of serotonin transmitter system in brain.