A new species of Euchalcia Hübner, [1821] from Kazakhstan (Lepidoptera, Noctuidae)

Volynkin, Anton V., Titov, Sergey V., Ivanova, Maria S. (2014): A new species of Euchalcia Hübner, [1821] from Kazakhstan (Lepidoptera, Noctuidae). Zootaxa 3784 (4): 493-497, DOI: 10.11646/zootaxa.3784.4.

Evidence of Volatility Metals and Metalloids at Environment Conditions

Tailings represent a significant risk to the environment globally, but very little is known about the composition of the near-surface air. We conducted laboratory experiments to determine the sizes of the particles and the chemical composition of the flow above the mine waste. A condensate of vapor–gas flow was collected in parallel with particle control by an aerosol diffusion spectrometer (ADS). We reveal that there were no aerosol particles bigger than 3 nm in the flow. The collected condensate contained chemical elements, ions of sulfates, chlorides, phosphates, and formates and a wide range of sulfur-, selenium-, and carbon-containing gases. The main findings of the study are the presence of the metals Zn, Cu, Fe, Al, Cd, Ni, and Ba and the metalloids As, Sb, Se, Ag, Co, Ti, and V in the true-gas phase or in the form of particles smaller than 3 nm in the air above the mine tailings. The surprising fact is that the migration of metals and metalloids in a true-gas form or in ultrafine particles (<3 nm) is possible, which opens up a new research direction on the volatile forms of chemical elements in various climatic conditions and their bioavailability and toxicity

Determination of Arsenic Species Distribution in Arsenide Tailings and Leakage Using Geochemical and Geophysical Methods

This study describes the distribution of arsenic mobile species in the tailings of Cu–Co–Ni–arsenide using the sequential extraction and determining the contents of arsenate (AsV) and arsenite (AsIII). The object of this study is the tailings ponds of the Tuvakobalt plant, which contains waste from the hydrometallurgical arsenide ore processing of the Khovu-Aksy deposit (Republic of Tuva, Russia). A procedure of sequential extraction for arsenic was applied, and it includes the extraction of the following forms: water-soluble, potentially water-soluble and exchangeable, easily sorbed on the surface of carbonates, associated with Fe/Mn oxides/hydroxides, associated with easily oxidized minerals, and accounted for by non-oxidized arsenic minerals. This procedure, which takes into account the peculiarities of the physical and chemical composition of the waste, was supplemented by the analytical determination of the arsenite and arsenate content by using the methods of inductively coupled plasma atomic emission spectrometry (ICP-AES) combined with the hydride generation technique (HG-ICP-AES). The content of the most mobile forms of arsenic, which are water-soluble, potentially water-soluble, and exchangeable species, is equal to 56% of the total arsenic content, 23% and 33% of which are arsenite and arsenate, respectively. Unlike arsenic, the mobile forms of metals have been determined in small quantities. The largest proportion of water-soluble and exchangeable forms is formed by Mg, Ca, and Sr at 11, 9.4, and 20%, respectively (residual and redeposited carbonates). The proportion of water-soluble forms of other metals (Cu, Zn, Co, and Ni) is < 1% or 0. The main part of the metals is adsorbed on the surface of Fe and Mn hydroxides, enclosed in easily and hardly oxidized minerals. In addition to geochemical studies, the presence of leaks from the tailing ponds into ground waters was determined by using electrical resistivity tomography. The data obtained indicate a high environmental hazard of tailings and the possibility of water-soluble and highly toxic arsenic compounds entering ground waters and aquifers

Cinnamal Sensing and Luminescence Color Tuning in a Series of Rare-Earth Metal−Organic Frameworks with Trans-1,4-cyclohexanedicarboxylate

Three isostructural metal–organic frameworks ([Ln2(phen)2(NO3)2(chdc)2]·2DMF (Ln3+ = Y3+ for 1, Eu3+ for 2 or Tb3+ for 3; phen = 1,10-phenanthroline; H2chdc = trans-1,4-cyclohexanedicarboxylic acid) were synthesized and characterized. The compounds are based on a binuclear block {M2(phen)2(NO3)2(OOCR)4} assembled into a two-dime nsional square-grid network containing tetragonal channels with 26% total solvent-accessible volume. Yttrium (1)-, europium (2)- and terbium (3)-based structures emit in the blue, red and green regions, respectively, representing the basic colors of the standard RGB matrix. A doping of Eu3+ and/or Tb3+ centers into the Y3+-based phase led to mixed-metal compositions with tunable emission color and high quantum yields (QY) up to 84%. The bright luminescence of a suspension of microcrystalline 3 in DMF (QY = 78%) is effectively quenched by diluted cinnamaldehyde (cinnamal) solutions at millimolar concentrations, suggesting a convenient and analytically viable sensing method for this important chemical