Fe(3)O(4)/polyethylene glycol nanocomposite as a solid-phase microextraction fiber coating for the determination of some volatile organic compounds in water.

A high-performance metal oxide polymer magnetite/polyethylene glycol nanocomposite was prepared and coated in situ on the surface of the optical fiber by sol-gel technology. The magnetite nanoparticles as nanofillers were synthesized by a coprecipitation method and bonded with polyethylene glycol as a polymer. The chemically bonded coating was evaluated for the headspace solid-phase microextraction of some environmentally important volatile organic compounds from aqueous samples in combination with gas chromatography and mass spectrometry.

Physical Training Status Determines Oxidative Stress and Redox Changes in Response to an Acute Aerobic Exercise.

Objective. To assess the influence of different physical training status on exercise-induced oxidative stress and changes in cellular redox state. Methods.

All-in-one solid-phase microextraction: Development of a selective solid-phase microextraction fiber assembly for the simultaneous and efficient extraction of analytes with different polarities.

In the present work, for the first time, an all-in-one solid-phase microextraction technique was developed for the simultaneous and efficient extraction of analytes within a vast polarity range. A novel fiber assembly composed of two different steel components each coated with different coatings (polydimethylsiloxane and polyethylene glycol) in terms of polarity by sol-gel technology was employed for the extraction of model compounds of different polarity in a single run followed by gas chromatography with mass spectrometry. Effective parameters in the extraction step and gas chromatography with mass spectrometry analysis were optimized for all model compounds.

Polyvinylimidazole/sol-gel composite as a novel solid-phase microextraction coating for the determination of halogenated benzenes from aqueous solutions.

A polyvinylimidazole/sol-gel composite is proposed as a novel solid-phase microextraction fiber to extract five halobenzenes from the headspace of aqueous solutions in combination with gas chromatography with mass spectrometry. The prepared fiber was characterized by scanning electron microscopy and Fourier transform infrared spectroscopy. The obtained results showed that porous polyvinylimidazole/sol-gel composite was chemically deposited on fused silica fiber.

Enhanced thebaine production in Papaver bracteatum cell suspension culture by combination of elicitation and precursor feeding.

In this study, the effect of methyl jasmonate (MJ) and ultrasound (US), individually and in combination with L-tyrosine, on the stimulation of thebaine production in Papaver bracteatum cell suspension cultures was studied. The addition of L-tyrosine did not significantly affect the cell biomass, but significantly increased the thebaine yield of cells compared with the control. The synergistic effects of MJ and L-tyrosine in the combined treatment of 100 μM MJ and 2 mM L-tyrosine increased the thebaine yield of cells up to 84.