Spectrophotometric determination of trace amount of iron in water, food, and pharmaceutical samples

The present study aimed to determine the trace amount of iron by using highly selective and sensitive spectrophotometric reagents in water, food, and pharmaceutical samples. For this, as-triazine containing ferroin-yielding chromogens; 3-(2-pyridyl)-5,6-diphenyl-1,2,4-triazine (PDT) and 3-(2-pyridyl)-5,6-bis(p-methoxyphenyl)-1,2,4-triazine (PBMPT) have been synthesized. The absorptiometric characteristics of the iron(II) complexes with PDT and PBMPT such as complex formation, sensitivity determination, composition determination have also been studied. It has been observed that these highly sensitive and selective ferroin-yielding reagents act as bidentate ligands and form intensive colored tris-complexes with iron(II) ions. The application of these spectrophotometric reagents for the determination of iron in water, food, and pharmaceutical samples has been described. Bangladesh J. Sci. Ind. Res.56(4), 299-306, 2021

Effect of silicon on elemental composition determination of mineral samples

In this paper, the effect of the silicon content in the sample solution on obtaining reliable analysis results of macro- and microcomponents of a mineral sample is shown. The methods for sample preparation and analysis are proposed. It should be noted that it is important to take into account the polycondensation reaction of silicic acids, its effect on the shelf life of the sample without the formation of polymer forms.

Features of morphotypic selection in populations of Serratula coronata L. cultivated in the conditions of the Moscow region

The article presents the results of morphotypic analysis of populations of perennial medicinal and fodder crops cultivated in the Moscow region (Serratula coronata L.). In the introduction, the botanical characteristics of the crowned sickle are given, the prospects and advantages of phytoecdysteroids obtained from raw materials are noted. The aim of the study is a comparative assessment of cultivated populations of S. coronata by morphotypic composition, determination of the age period for the selection of initial forms for breeding. The object of the study was the different geographical origin S. coronata three cultivated populations (Samarskaya, Belgorodskaya, Syktyvkarskaya from Rep. Komi). We have tested the application of methods for assessing varieties by uniformity, distinctness, stability for morphotypic selection in the population when creating improved, initial and breeding material. The article presents the results of the analysis of the morphotypic composition of populations by morphological characteristics and the productivity of raw materials according to long-term data (2013-2017, Moscow region, VILAR), the age period during which morphotypic selection should be carried out is established, morphotypes that are of the greatest value during selection are identified and described. The age period during which morphotypic selection should be carried out is established: 3-5 year, since the morphotype is fully formed by the 3rd year. It is established that plants in cultivated populations of Serratula coronata are represented by 2-3 morphotypes based on the height and leafiness of the generative shoot, the length of the stem leaves and the mass of the shoot. When selecting, the highest value is represented by tall morphotypes with medium-length leaves (~60-70% of them in each population), but morphotypes with medium leafiness should be selected among them (only ~41-51% of them in each population, only in the Syktyvkarskaya population – up to 69 %). The results of the study are relevant in the aspect of creating an improved, initial and breeding material of the Serratula coronata. Keywords: MEDICINAL PLANTS, SERRATULA CORONATA L., PHENOTYPIC VARIABILITY, MORPHOTYPE, POPULATION, PRODUCTIVITY, QUANTITATIVE CHARACTERISTICS, SELECTION

On the Utility of Longwave-Infrared Spectral Imaging for Remote Botanical Identification

A multi-year airborne field investigation of remote botanical species identification was conducted involving multiple curated botanical collections. The purpose of the study was to better constrain the observational conditions that most favor remote identification by longwave-infrared spectral imaging and assess the degree to which confidence metrics developed for remote chemical composition determination could be adapted to botanical species classification. Identification success was examined as a function of spatial resolution and viewing obliquity. A key aim was to articulate a procedure for validating inferred species identifications and evaluating the retrieval methodology’s performance for alleviating confusion between species exhibiting spectral similarity at the foliar scale. It was found that several confounding factors degrade confidence in the species identifications to levels that render the approach impractical in the general case. A number of taxa, predominantly evergreen, were nevertheless identified that are amenable to the technique and for which utility may be viable.

Capillary Electrophoresis as a Monitoring Tool for Flow Composition Determination

Flow analysis is the science of performing quantitative analytical chemistry in flowing streams. Because of its efficiency and speed of analysis, capillary electrophoresis (CE) is a prospective method for the monitoring of a flow composition withdrawn from various processes (e.g., occurring in bioreactors, fermentations, enzymatic assays, and microdialysis samples). However, interfacing CE to a various flow of interest requires further study. In this paper, several ingenious approaches on interfacing flow from various chemical or bioprocesses to a capillary electrophoresis instrument are reviewed. Most of these interfaces can be described as computer-controlled autosamplers. Even though most of the described interfaces waste too many samples, many interesting and important applications of the devices are reported. However, the lack of commercially available devices prevents the wide application of CE for flow analysis. On the contrary, this fact opens up a potential avenue for future research in the field of flow sampling by CE.