Chemical sensors for heavy metals/toxin detection

Nowadays, the huge release of pollutants into the environment has become a significant problem in many countries and entire regions [...

Recent advances in chemical sensors for soil analysis: a review

The continuously rising interest in chemical sensors' applications in environmental monitoring, for soil analysis in particular, is owed to the sufficient sensitivity and selectivity of these analytical devices, their low costs, their simple measurement setups, and the possibility to perform online and in-field analyses with them. In this review the recent advances in chemical sensors for soil analysis are summarized. The working principles of chemical sensors involved in soil analysis; their benefits and drawbacks; and select applications of both the single selective sensors and multisensor systems for assessments of main plant nutrition components, pollutants, and other important soil parameters (pH, moisture content, salinity, exhaled gases, etc.) of the past two decades with a focus on the last 5 years (from 2017 to 2021) are overviewed

The new approach to a pattern recognition of volatile compounds: the inflammation markers in nasal mucus swabs from calves using the gas sensor array

This paper discusses the application of two approaches (direct and inverse) to the identification of volatile substances by means of a gas sensor array in a headspace over nasal mucus swab samples taken from calves with differing degrees of respiratory damage. We propose a unique method to visualize sensor array data for quality analysis, based on the spectra of cross mass sensitivity parameters. The traditional method, which requires an initial sensor array trained on the vapors of the individual substances (database accumulation)-with their further identification in the analyzed bio-samples through the comparison of the analysis results to the database-has shown unsatisfactory performance. The proposed inverse approach is more informative for the pattern recognition of volatile substances in the headspace of mucus samples. The projection of the calculated parameters of the sensor array for individual substances in the principal component space, acquired while processing the sensor array output from nasal swab samples, has allowed us to divide animals into groups according to the clinical diagnosis of their lung condition (healthy respiratory system, bronchitis, or bronchopneumonia). The substances detected in the gas phase of the nasal swab samples (cyclohexanone, butanone-2,4-methyl-2-pentanone) were correlated with the clinical state of the animals, and were consistent with the reference data on disease markers in exhaled air established for destructive organism processes

The long-lasting story of one sensor development: from novel ionophore design toward the sensor selectivity modeling and lifetime improvement

The metalloporphyrin ligand bearing incorporated anion-exchanger fragment, 5-[4-(3-trimethylammonium)propyloxyphenyl]-10,15,20-triphenylporphyrinate of Co(II) chloride, CoTPP-N, has been tested as anion-selective ionophore in PVC-based solvent polymeric membrane sensors. A plausible sensor working mechanism includes the axial coordination of the target anion on ionophore metal center followed by the formed complex aggregation with the second ionophore molecule through positively charged anion-exchanger fragment. The UV-visible spectroscopic studies in solution have revealed that the analyte concentration increase induces the J-type porphyrin aggregation. Polymeric membranes doped with CoTPP-N showed close to the theoretical Nernstian response toward nitrite ion, preferably coordinated by the ionophore, and were dependent on the presence of additional membrane-active components (lipophilic ionic sites and ionophore) in the membrane phase. The resulting selectivity was a subject of specific interaction and/or steric factors. Moreover, it was demonstrated theoretically and confirmed experimentally that the selection of a proper ratio of ionophore and anionic additive can optimize the sensor selectivity and lifetime

Keeping track of phaeodactylum tricornutum (Bacillariophyta) culture contamination by potentiometric e-tongue

The large-scale cultivation of microalgae provides a wide spectrum of marketable bioproducts, profitably used in many fields, from the preparation of functional health products and feed supplement in aquaculture and animal husbandry to biofuels and green chemistry agents. The commercially successful algal biomass production requires effective strategies to maintain the process at desired productivity and stability levels. Hence, the development of effective early warning methods to timely indicate remedial actions and to undertake countermeasures is extremely important to avoid culture collapse and consequent economic losses. With the aim to develop an early warning method of algal contamination, the potentiometric E-tongue was applied to record the variations in the culture environments, over the whole growth process, of two unialgal cultures, Phaeodactylum tricornutum and a microalgal contaminant, along with those of their mixed culture. The E-tongue system ability to distinguish the cultures and to predict their growth stage, through the application of multivariate data analysis, was shown. A PLS regression method applied to the E-tongue output data allowed a good prediction of culture growth time, expressed as growth days, with R-2 values in a range from 0.913 to 0.960 and RMSEP of 1.97-2.38 days. Moreover, the SIMCA and PLS-DA techniques were useful for cultures contamination monitoring. The constructed PLS-DA model properly discriminated 67% of cultures through the analysis of their growth media, i.e., environments, thus proving the potential of the E-tongue system for a real time monitoring of contamination in microalgal intensive cultivation

Experience of Developing a database of storytellers of the Yakut Epos

The results of the analysis of the basic principles of compiling the database “Olonkhosuts of Yakutia of the 17th—20th centuries” — about the storytellers of the Yakut national epic are presented. The relevance of the research is determined by some difficulties in the systematization and design of the information content of the repository. A brief overview of the history of the study of the personalities of Yakut storytellers is given, the stages of database development are discussed in detail. It is noted that as a result of the generalization of the material a reference book that contains more than 1300 names of storytellers of the 17th-20th centuries was published by the team of the Olonkho Research Institute of M. K. Ammosov North-Eastern Federal University. Problems identified in the process of filling in the cells are described. Particular attention is paid to entering data in the national language, their transliteration and translation into Russian. The definition of the types of the second names of olonkhosuts is given, the expediency of allocating a separate field for nicknames-pseudonyms reflecting the status and popular recognition of the talent of the narrator is substantiated. A sample database table on olonkhosuts is presented. As a result of the study, the parameters for selecting data for inclusion in the repository were compiled, the need for additional research work to identify the facts of the change of residence of olonkhosuts was determined, and recommendations were proposed for improving the principles of information content of the database

Subjects of Tax Legal Relations

The article deals with issues related to classification and certain aspects of the legal status of subjects of tax legal relations, the concepts of “subjects of tax law”, “subjects of tax legal relations”, “participants in tax legal relations” are compared. The analysis of various classifications of subjects of tax legal relations is carried out with a more detailed study of classification by the method of normative certainty. The composition of the subjects fixed by the tax legislation and subjects not included in the list of participants in tax legal relations, as defined in Article 9 of the Tax Code of the Russian Federation, is detailed. As a result of the study, measures are proposed to improve tax legislation

Damage to Public Legal Institutions as a Category of Financial Law

The article is devoted to the problems associated with the changes made to the draft of the new version of the Budget Code of the Russian Federation concerning the assessment of the severity of violations of the budget legislation for the purpose of administrative or criminal liability measures. The article deals with the issues of improving the conceptual apparatus, including the term “damage to public legal institutions”. The comparative analysis of categories “harm”, “loss” and “damage” is carried out. An attempt is made to define the concept of “damage to public legal institutions” as a category of financial (budget) law. The issues of delimitation of violations of the budget legislation from the shortcomings in the activities of public authorities and local selfgovernment, leading to inefficient use of budgetary funds. It is concluded that it is necessary to include in the new edition of the Budget Code such categories as “violations and shortcomings associated with the use of budgetary funds”, “inefficient use of budgetary funds”, “damage to public legal institutions”, as well as the development of a special method of calculating the damage to public legal institutions

Photographic detection of Cadmium(II) and Zinc(II) ions

The binding properties of two 2,8-dithia-5-aza-2,6-pyridinophane-based ligands, bearing respectively coumarin (HNCum) and naphthol-benzoxaazole (HNBO) optically active units as pendant arms, were studied with the aim of transition metal cations selective detection. The novel all-solid-state optodes were obtained by inclusion of fluorophores inside PVC-based polymeric films. The influence of lipophilic sites incorporation and plasticizer nature on pyridinophane-based optodes response was investigated. An enhanced selectivity of the ligands towards Cadmium(II) and Zinc(II) ions was detected. Light Emitting Diode, LED 380 nm, was used as light source, and a digital camera as a signal detector. The results obtained demonstrated the suitability of the developed optodes to perform fast and low cost simultaneous monitoring of Zn2+and Cd2+ ions by means of familiar devices and chemometrics. © 2016 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license