Determination of 28 selected elements in textiles by axially viewed inductively coupled plasma optical emission spectrometry

A simple, robust and reliable analytical procedure for the determination of 28 selected elements, namely Al, As, Ba, Be, Bi, Ca, Cd, Co, Cr, Cu, Fe, K, Hg, Mg, Mn, Mo, Na, Ni, Pb, Sc, Si, Se, Sn, Sm, Sr, Tl, V, and Zn in textile materials by inductively coupled plasma optical emission spectrometry (ICP-OES) after microwave digestion of samples was optimized and validated in this work. The total amount of elements present in textile samples was determined after microwave digestion of materials in 7 mol/L nitric acid within the optimal working program: 5 min at 150 °C (power 250 W), 15 min 180 °C (300 W) and 20 min at the maximum temperature of 200 °C (350 W). For the quality control reasons, which were ascertained by analysis of the certified cotton trace elements reference material IAEA-V9, the ICP-OES method was optimized through several parameters: by comparing Meinhard and Gemcone Low Flow nebulizers efficiency, ranging nebulizer gas flows from 0.6 to 1.0 L/min, ranging sample flows from 0.8 to 1.2 mL/min, testing RF power from 1200 to 1400 W, detecting data acquisition time (read time) from 0 to 527 s, ranging washing (delay) time from 0 to 408 s, as well as by checking the occurring interferences for the optimal line selection. Validation included determination of linearity, selectivity, accuracy, reproducibility, precision and limits of detection calculated for all 28 selected elements of interest. The developed analytical procedure was successfully applied on textile fibers (cotton, flax and hemp) as well as on standard knitted textile sample materials (cotton and wool).     

Determination of engineered nanoparticles on textiles and in textile wastewaters

Textile materials with engineered nanoparticles (ENPs) have excellent properties as they are antibacterial, antimicrobial, water resistant and protective. The textile industry has recognized the importance and the advantages of ENPs, so they comprise one of the fastest developing branches of processing.The most important sources of ENPs released to the environment from textiles are textile-industry wastewaters and waters from large hospital or hotel laundries. In addition, waste textile materials coated with ENPs present a threat to the environment, if such materials are not properly handled and disposed of after use.Currently, the toxicity and the potential harm of ENPs widely applied on textiles are not thoroughly investigated and/or eliminated. Consequently, there is an urgent need to define the most appropriate analytical methods for monitoring ENPs on textiles.This review presents the most important techniques for monitoring ENPs on textile materials and in textile-wastewater samples, from the perspective of protecting the environment and human health.     

Use of Genetic Algorithms and Artificial Neural Networks to Predict the Resolution of Amino Acids in Thin-Layer Chromatography

JPC – Journal of Planar Chromatography – Modern TLC - A novel method is proposed for optimization of simultaneous thinlayer chromatographic separation of seven amino acids. For this...     

Unexpected Enhancement of Antimicrobial Polymer Activity against Staphylococcus aureus in the Presence of Fetal Bovine Serum

Cationic and amphiphilic polymers are known to exert broad-spectrum antibacterial activity by a putative mechanism of membrane disruption. Typically, nonspecific binding to hydrophobic components of the complex biological milieu, such as globular proteins, is considered a deterrent to the successful application of such polymers. To evaluate the extent to which serum deactivates antibacterial polymethacrylates, we compared their minimum inhibitory concentrations in the presence and absence of fetal bovine serum. Surprisingly, we discovered that the addition of fetal bovine serum (FBS) to the assay media in fact enhances the antimicrobial activity of polymers against Gram-positive bacteria S. aureus, whereas the opposite is the case for Gram-negative E. coli. Here, we present these unexpected trends and develop a hypothesis to potentially explain this unusual phenomenon.     

Unusual p‐Coumarates from the Stems of Vaccinium myrtillus

The two previously unreported esters 1 and 2 of pentane‐2,4‐diol and p‐coumaric acid (=3‐(4‐hydroxyphenyl)prop‐2‐enoic acid) along with 13 known compounds including 6 oleanane‐ and ursane‐type triterpenoids were isolated from MeOH extracts of the stems of Vaccinium myrtillus. The structures of the new compounds were assigned as (2S,4R)‐4‐(β‐D ‐glucopyranosyloxy)pentan‐2‐yl (2E)‐p‐coumarate ( 1 ) and its aglycone 2 on the basis of 1D‐ and 2D‐NMR spectroscopic analyses of the isolated and synthesized compounds and molecular modelling experiments. This is the first report on the occurrence of a chiral pentane‐2,4‐diol linker between the phenol‐derived acid and a glycoside part in natural products.     

ICP-MS Determination of Antimicrobial Metals in Microcapsules

Silver (Ag) and zinc (Zn) are very powerful antimicrobial metals. Therefore, in this research, a high-throughput, sensitive, and rapid method was developed for the determination of Ag and Zn in microcapsules using inductively coupled plasma mass spectrometry (ICP-MS). The sample preparation procedure employed simple microwave digestion of the microcapsules with 55.55% v/v HNO₃ and 44.45% v/v H₂O₂. The method was applied to determine Ag and Zn in microcapsule samples of different sizes (120 and 450 μm) after their preparation with and without chitosan. Prepared microcapsules, after characterization, were bonded to a polymer carrier by sol-gel procedure and the materials were characterized by FTIR spectroscopy and high-resolution optical microscopy. Significant differences were found in Ag and Zn levels between microcapsules samples prepared with and without chitosan. The results have shown that samples with chitosan had up to 20% higher levels of Zn than Ag: 120 μm microcapsules contained 351.50 μg/g of Ag and 85.51 μg/g of Zn, respectively. In contrast, samples prepared without chitosan showed larger overall variability: In microcapsules with a diameter of 120 μm, the amounts of antimicrobial metals were 98.32 μg/g of Ag and 106.75 μg of Zn, respectively. Moreover, 450 μm microcapsules contained 190.98 μg/g of Ag and 121.35 μg/g of Zn. Those quantities are high enough for efficient antimicrobial activity of newly prepared microcapsules, enabling the application of microcapsules in different antimicrobial coatings.     

Ring‐functionalized niobocene complexes

A series of new ring‐functionalized niobocene dichloride compounds (RCH₂C₅H₄)₂NbCl₂ (R = MeOCH₂, (CH₂)₅NCH₂, 2‐MeOC₆H₄, 3‐MeOC₆H₄, 4‐MeOC₆H₄, 2,4‐(MeO)₂C₆H₃, 3,4‐(MeO)₂C₆H₃, 2,4,6‐(MeO)₃C₆H₂, 3,4,5‐(MeO)₃C₆H₂, 4‐FC₆H₄, 4‐Me₂NC₆H₄) was synthesized and characterized by electron paramagnetic resonance. Three structures were determined by X‐ray diffraction analysis and revealed the expected bent metallocene structure with two cyclopentadienyl ligands and two chlorides coordinated to niobium in the oxidation state IV. Chlorides and the centroids of the η⁵‐bonded cyclopentadienyl rings define a distorted tetrahedron. The cytotoxicity study has demonstrated that substitution with methoxybenzyl groups can lead to highly active species, but the activity strongly varies with the number and positions of the methoxy groups in the benzene ring. The most active species under study – {2,4‐(MeO)₂C₆H₃CH₂C₅H₄}₂NbCl₂ – has a maximal inhibitory concentration value comparable with cisplatin. Copyright © 2014 John Wiley & Sons, Ltd.     

Pre-equilibrium emission in neutron induced reactions on54,56Fe

The experimentally well known (n, p), (n, α) and (n, 2n) reaction excitation functions, from threshold to 20 MeV incident energy, and neutron and proton emission spectra at 14.8 MeV from^54,56Fe targets are calculated in the frame of the Geometry-Dependent Hybrid pre-equilibrium emission model, including angular momentum and parity conservation, and the Hauser-Feshbach statistical model. Use of a consistent statistical model parameter set enables the validation of the pre-equilibrium emission model. Moreover, an enhanced pre-equilibrium emission from higher spin composite system states, associated with higher incoming orbital momenta, has been evidenced. Higher orbital momenta involved also in the emergent channels of the process are suggested by calculations of the residual nuclei level populations.