Content of Phenol Carboxylic Acids in the Water among Higher Aquatic Plants of Various Ecological Groups

The composition and content of phenol carboxylic acids was studied in water bodies among higher aquatic plants of various ecological groups: emergent (Typha angustifolia L., Scirpus lacustris L., and Phragmites australis (Cav.) Trin. ex Steud.), submerged (Ceratophyllum demersum L. and Myriophyllum spicatum L.), and with floating leaves (Trapa natans L. and Nuphar lutea L.). The following acids were found in the water among higher aquatic plants: benzoic, lilac, vanillic, gallic, n-oxybenzoic, protocatechuic, α-resorcylic, β-resorcylic, salicylic, ferulic, caffeic, cinnamic, coumaric, and sinapic. Their total concentration in the water among the specimens of T. angustifolia accounted for 114.7 μg/L, Sc. lacustris - 24.71 μg/L, T. natans - 56.14 μg/L, N. lutea -19.3 μg/L, C. demersum -25.42-38.66 μg/L, and M. spicatum - 1.42-2.83 μg/L. The analysis of the content of phenol carboxylic acids in the water among the specimens of Ph. australis during the spring-autumn period revealed significant differences both in the ratio of individual acids and in their distribution by groups. The maximal concentration of benzoic and salicylic acids in the water was registered at the beginning of Ph. australis development, whereas the maximal content of vanillic and gallic acids - during plant active vegetation. The lowest content of cinnamic and ferulic acids was recorded at the beginning of vegetation season. Cluster analysis of the content of phenol carboxylic acids in the water among the specimens of C. demersum and M. spicatum at two sampling stations (Sobache Gyrlo Bay and Verblyud Bay in the Kaniv Reservoir) made it possible to reveal two groups of the studied substances. The first group included benzoic and gallic acids and the second group - other acids. The use of the principal component analysis (PCA) made it possible to establish a significant correlation between the composition and content of phenol carboxylic acids in the water among higher aquatic plants and dominant plant species. This fact is indicative of the leading role of higher aquatic plants in the formation of the pool of these substances in the water.