Hydrogen Peroxide-oxidized Soybean Polysaccharides as Novel Masking Agents for Zirconium Tanning

A series of hydrogen peroxide-oxidized soybean polysaccharides (HPS) were prepared using H2O2 and copper catalyst, which were then used as novel masking agents for zirconium tanning. The HPS samples were characterized by Fourier transforms infrared (FT-IR) spectroscopy, dynamic light scattering (DLS), and X-ray diffraction (XRD). FT-IR suggested the formation of carbonyl and carboxyl groups after hydrogen peroxide oxidation. DLS indicated that the HPS particle size decreases with increasing the H2O2 dosage. HPS with carbonyl and carboxyl groups and medium particle size was able to coordinate with zirconium to remarkably facilitate the tanning process. The shrinkage temperature of the tanned leather reached 92oC. Meanwhile, the fullness, softness, and mechanical properties of the leather were greatly improved by the tanning. The function of HPS and its interaction with zirconium were studied by FT-IR, XRD, and it was found that the triple helical structures of collagen fiber were not changed greatly. Scanning electron microscopy (SEM) showed that collagen fibers were dispersed and tanning agents were evenly distributed in collagen fibers. A new strategy for chromefree tanning is suggested and a strong support for the application of zirconium tanning is provided.

Trp-Trp acts as a multi-functional blocker for human bitter taste receptors, hTAS2R14, hTAS2R16, hTAS2R43, and hTAS2R46

Many functional food ingredients activate human bitter taste receptors (hTAS2Rs). In this study, A novel inhibitor, Trp-Trp, for hTAS2R14 was identified by searching for the agonist peptide's analogs. Trp-Trp also inhibited hTAS2R16, hTAS2R43, and hTAS2R46, which share the same agonists with hTAS2R14. The multi-functional characteristic of Trp-Trp is advantageous for use as bitterness-masking agents in functional foods.

Syntheses and evaluation of new hydrophilic azacryptands used as masking agents of technetium in solvent extraction processes

New azacryptands with the addition of hydrophilic groups were synthesized to bind selectively the pertechnetate anion in nitric acid medium, and avoid its extraction in the separation process.

An in vivo Bioelectronics Nose for Possible Quantitative Evaluation of Odor Masking Using M/T Cells Spatial Response Patterns

Odor masking is a prominent phenomenon in the biological olfactory perception system. It has been applied in industry and daily life to develop masking agents to reduce or even eliminate...

Masking Ability of Various Metal Complexing Ligands at 1.0 mM Concentrations on the Potentiometric Determination of Fluoride in Aqueous Samples

Fluoride is a common anion present in natural waters. Among many analytical methods used for the quantification of fluoride in natural waters, potentiometric analysis is one of the most widely used methods because of minimum interferences from other ions commonly present in natural waters. The potentiometric analysis requires the use of ionic strength adjusting buffer abbreviated as TISAB to obtain accurate and reproducible data. In most of the reported literature, higher concentrations of strong metal chelating ligands are used as masking agents generally in the concentration range of 1.0 to 0.01 M. In the present study, effectiveness of the masking agents, phosphate, citrate, CDTA ((1,2-cyclohexylenedinitrilo)tetraacetic acid), EDTA (ethylenediaminetetraacetic acid) HE-EDTA ((hydroxyethyl)ethylenediaminetriacetic acid)), triethanolamine, and tartaric acid at 1.0 mM in TISAB solutions was investigated. The experimental data were compared with a commercially available WTW 140100 TISAB solution as the reference buffer. According to the experimental data, the reference buffer always produced the highest fluoride concentrations and the measured fluoride concentrations were in the range of 0.611 to 1.956 mg/L. Out of all the masking agents investigated, only CDTA performed marginally well and approximately a quarter of the samples produced statistically comparable data to the reference buffer. All the other masking agents produced significantly low concentrations compared to the reference buffer. The most probable reasons for the underestimation of fluoride concentrations could be shorter decomplexing time and lower masking agent concentrations.

Online Turbulent Flow Extraction and Column Switching for the Confirmatory Analysis of Stimulants in Urine by Liquid Chromatography–Mass Spectrometry

Stimulants are often used to treat attention deficit disorders and nasal congestion. As they can be misused and overdosed, the detection of stimulants is relevant in the toxicological field as well as in the doping control field. The effects of stimulants can indeed be beneficial for athletes. Therefore, their in-competition use is prohibited by the World Anti-Doping Agency (WADA). As stimulants represent one of the most detected categories of prohibited substances, automation of methods to detect and confirm their presence is desirable. Previous work has shown the advantages of using turbulent flow online solid-phase extraction liquid chromatography–tandem mass spectrometry (online SPE LC–MS-MS) for the detection and confirmation of diuretics and masking agents. Hence, a turbulent flow online SPE LC–MS-MS method, compliant with the WADA’s identification criteria, was developed and validated for the detection and confirmation of 80 stimulants or metabolites with limits of identification varying between 10 (or possibly lower) and 100 ng/mL. As several metabolites are common metabolites for multiple administered stimulants, this means that with this method, misuse of well over 100 compounds can be detected. As the developed method uses the same columns and mobile phases as our turbulent flow online SPE LC–MS-MS method for the confirmation of diuretics and masking agents, there is no need to change the configuration of the instrument when switching between the diuretics method and the developed stimulants method.

Reducing topramezone injury to bermudagrass using chelated iron and other additives

POST goosegrass and other grassy weed control in bermudagrass is problematic. Fewer herbicides that can control goosegrass are available due to regulatory pressure and herbicide resistance. Alternative herbicide options that offer effective control are needed. Previous research demonstrates that topramezone controls goosegrass, crabgrass, and other weed species; however, injury to bermudagrass may be unacceptable. The objective of this research was to evaluate the safening potential of topramezone combinations with different additives on bermudagrass. Field trials were conducted at Auburn University during summer and fall from 2015 to 2018 and 2017 to 2018, respectively. Treatments included topramezone mixtures and methylated seed oil applied in combination with five different additives: triclopyr, green turf pigment, green turf paint, ammonium sulfate, and chelated iron. Bermudagrass bleaching and necrosis symptoms were visually rated. Normalized-difference vegetative index measurements and clipping yield data were also collected. Topramezone plus chelated iron, as well as topramezone plus triclopyr, reduced bleaching potential the best; however, the combination of topramezone plus triclopyr resulted in necrosis that outweighed reductions in bleaching. Masking agents such as green turf paint and green turf pigment were ineffective in reducing injury when applied with topramezone. The combination of topramezone plus ammonium sulfate should be avoided because of the high level of necrosis. Topramezone-associated bleaching symptoms were transient and lasted 7 to 14 d on average. Findings from this research suggest that chelated iron added to topramezone and methylated seed oil mixtures acted as a safener on bermudagrass.

Spectrophotometric Determination of Cu(II) in Analytical Sample Using a New Chromogenic Reagent (HPEDN)

The sensitive, accurate and rapid spectrophotometric method that can be used for determination of Cu(II) in the analytical samples using a new chromogenic reagent azo-Schiff base 1-((4-(1-(2-hydroxyphenylimino)ethyl)-phenyl)diazenyl) naphthalene-2-ol (HPEDN). The synthesized new (azo-Schiff base) ligand was complexed with copper(II) and characterized using UV/Vis spectroscopy, IR spectra, 1H-NMR, 13CN-MR spectra, Molar electrical connectivity, and measuring of their melting points. Then obtained complex showed a brown color with maximum absorption at λmax = 500 nm at pH = 9. Beer’s law is obeyed in the concentration in the range of 1.7 to 5.4 μg/mL. The molar absorption and Sandell’s sensitivity values of Cu(II) complex were found to be 0.5038 × 104 L mol–1 cm–1 and 0.0039 μg cm–2, respectively. Structure of the prepared complex was investigated by using the continuous variation, mole ratio method and slope analysis method. The obtained results showed that the complex has (1:2) (M:L) molar ratio and these results showed that this method were more sensitive, more precise and accuracy through the calculation of (Re, Erel, R.S.D)%. The most important interferences were due to, Co2+, Cd2+, Zn2+, Ni2+, Mn2+, Pd2+, Fe3+ and these were studied, and suitable masking agents were used. This method was applied for the determination of Cu(II) in alloy. The obtained results were compared with flame atomic absorption spectrometry method and these results were in a good agreement in these two cases.

Use of psychotropic substances in elite sports

Elite athletes may use psychotropic substances for recreational reasons, (perceived) performance enhancement or self-medication. Causes can hereby overlap. In substance use, recreational consumption aiming primarily at psychotropic effects is distinguished from performance-enhancing use (doping). Doping substances include anabolic agents, growth factors, masking agents and blood doping, which do not possess specific psychoactive effects. In substance use among elite athletes the scientific and media focus is on doping, however the use of psychotropic substances is an issue of medical importance.