Benjamin Salaković

Triazine derivatives are well-known commercially available compounds used for selective weed control in different crops, such as corn and sugarcane. Some of them are considered persistent organic compounds in the environment and it is important to improve the features of herbicide formulae, to estimate their physicochemical properties and to determine their retention behavior in modern analytical techniques that can be used in the determination of pesticides in environmental samples. The present study deals with a comprehensive analysis of the chromatographic behavior of a series of 6-chloro-1,3,5-triazines with alkyl and cycloalkyl substituents, among which some compounds possess herbicidal and fungicidal activity. The anisotropic lipophilicity of triazine derivatives was determined using reversed-phase ultra high performance liquid chromatography with octadecyl and phenyl columns and applying binary (methanol/water and acetonitrile/water) and ternary (methanol/acetonitrile/water) mobile phases under isocratic conditions. The retention data were analyzed using chemometric pattern recognition methods (hierarchical cluster analysis and principal component analysis) and sum of ranking differences method. The obtained results are excellent indicators of the retention behavior and the lipophilicity of the analyzed series of triazines and can serve as an outstanding basis for the development of new chromatographic methods for the determination of triazines in environmental samples.

The contamination of the environment by pesticides is becoming a burning issue in many countries in the World. Development, design, and synthesis of new eco-friendly pesticides and modification of existing ones in order to improve their efficacy with the lowest impact on the environment are two main future possibilities in crop protection and the provision of sufficient food for the growing world population. The present study is focused on the comparative analysis of a series of eight symmetrical triazine derivatives, as potential herbicide candidates with acyclic (alkyl) and cyclic (cycloalkyl) substituents, in terms of their antifungal activity towards Aspergillus flavus as an opportunistic fungal pathogenic microorganism responsible for frequent contaminations of crops with aflatoxin, and in terms of their potential application as herbicides in maize, common wheat, barley, and rice crops. The applied methods include the chemometric pattern recognition method (hierarchical cluster analysis), experimental microbiological analysis of antifungal activity (agar well-diffusion method), and molecular docking of the triazines in the corresponding enzymes. The main findings of the conducted study indicate the significant antifungal activity of the studied triazine derivatives towards A. flavus, particularly the compounds with acyclic substituents; five out of eight studied triazines could be applied as systematic herbicides, while the other three triazines could be used as contact herbicides; the compounds with acyclic substituents could be more suitable for application for various crops protection than triazines with cyclic substituents.

The aim of the work is to determine the acidity (pH) of milk produced on family farms in the Municipality of Sjenica depending on the season and month of production. It found an analysis of 3,226 milk samples that manufacturers and processors brought voluntarily to the lab. The process of receiving and analyzing the samples was done according to the Rulebook on the Quality of Raw Milk and ISO/IEC 17025:2017. The number of samples of raw milk in winter (529) is lower than in summer (1094). The average pH is the highest in the month of December (6.70), and the lowest in March (6.52). On the territory of the Municipality of Sjenica there was a steady acidity of milk per month in 2019. and moved within the boundaries envisioned in the Regulation on the Quality of Raw Milk.