Heterogeneous (gas-solid) chemistry of atmospheric Cr: A case study of Astana, Kazakhstan.

Hexavalent chromium (Cr(VI)) is a known carcinogen derived from both anthropogenic and natural sources. This work reports the size-segregated concentrations of total Cr(VI) in particulate matter (PM) in Astana, the capital of Kazakhstan, and provides new insights into the gas-solid reactions of atmospheric Cr. A study of total Cr(VI) in the particulate matter, via a microwave-assisted digestion technique, was conducted using a 5-stage Sioutas Cascade impactor that captures airborne particles in size ranges: >2.

Ultrasensitive fluorescent carbon dot sensor for quantification of soluble and insoluble Cr(VI) in particulate matter.

This study investigates advanced functional materials to address the need for practical and affordable analytical techniques for monitoring large amounts of insoluble Cr(VI). N,S-doped fluorescent carbon dots (f-CDs) were fabricated through microwave synthesis, with an average diameter of 10 nm. These f-CDs were explored as potential sensors for detecting Cr(VI) in ambient particulate matter (PM).

N,Zn-Doped Fluorescent Sensor Based on Carbon Dots for the Subnanomolar Detection of Soluble Cr(VI) Ions.

The development of a fluorescent sensor has attracted much attention for the detection of various toxic pollutants in the environment. In this work, fluorescent carbon dots (N,Zn-CDs) doped with nitrogen and zinc were synthesized using citric acid monohydrate and 4-pyridinecarboxyaldehyde as carbon and nitrogen sources, respectively. The synthesized N,Zn-CDs served as an "off" fluorescence detector for the rapid and sensitive detection of hexavalent chromium ions (Cr(VI)).

Quantification and the sources identification of total and insoluble hexavalent chromium in ambient PM: A case study of Aktobe, Kazakhstan.

Hexavalent chromium (Cr(VI)), a known carcinogen, emanates from both anthropogenic and natural sources. A pilot study of the ambient Cr(VI) concentrations was conducted at the center of Aktobe which is a few kilometers away from major industrial chromium plants. Total Cr(VI) concentrations were measured in the fall and winter seasons with mean values (S.

Formation of cluster mode particles (1-3 nm) in preschools.

This study is the first study that reports the cluster particle (1-3 nm) formation (CPF) in two modern preschools located in Nur-Sultan city of Kazakhstan from October 28 to November 27, 2019. The average particle number concentration and mode diameter values during major CPF events in Preschool I and Preschool II were found to be 1.90 × 10 (SD 6.

Exposure to fine, ultrafine particles and black carbon in two preschools in nur-sultan city of kazakhstan.

Children in preschools were studied as an exceptionally vulnerable group to lung diseases due to their immature immune system. Few data are available in the literature addressing the exposure of children in preschools to ultrafine (>10 nm) particles. Exposure of children to fine, ultrafine (10 nm-1 µm) particles and black carbon particles present inside and near two preschools in Nur-Sultan, Kazakhstan, during Fall 2019 was investigated.

Impact of volatile organic compounds on chromium containing atmospheric particulate: insights from molecular dynamics simulations.

The effect of volatile organic compounds (VOCs) on chromium-containing atmospheric particles remains obscured because of difficulties in experimental measurements. Moreover, several ambiguities exist in the literature related to accurate measurements of atmospheric chromium concentration to evaluate its toxicity. We investigated the interaction energies and diffusivity for several VOCs in chromium (III)-containing atmospheric particles using classical molecular dynamics simulations.

Zinc metal-organic framework with 3-pyridinecarboxaldehyde and trimesic acid as co-ligands for selective detection of Cr (VI) ions in aqueous solution.

There is an increasing need for the development of probes for the detection of hexavalent chromium since it is a known carcinogen, which can cause adverse effects on human health. Metal-organic frameworks (MOFs) have shown successful detection and removal of hazardous substances from aqueous media. This work presents the use of simple organic ligands such as 3-pyridinecarboxaldehyde and trimesic acid with Zn(II) ion to fabricate a new MOF that exhibits sensitive and selective luminescence quenching response towards CrO and CrO species in aqueous solution.