Considering the vast cultural and traditional heritage of the use of aromatic herbs and wildflowers for the treatment of light medical conditions in the Balkans, a comparison of the antioxidant capacity of wildflowers extracts from Herzegovina was studied using both cyclic voltammetry and spectrophotometry. The cyclic voltammograms taken in the potential range between 0 V and 800 mV and scan rate of 100 mV s−1 were used for the quantification of the electrochemical properties of polyphenols present in four aqueous plant extracts. Antioxidant capacity expressed as mmoL of gallic acid equivalents per gram of dried weight of the sample (mmoL GAE g−1 dw) was deduced from the area below the major anodic peaks (Q400 pH 6.0, Q500 pH 4.7, Q600 pH 3.6). The results of electrochemical measurements suggest that the major contributors of antioxidant properties of examined plants are polyphenolic compounds that contain ortho-dihydroxy-phenol or gallate groups. Using Ferric reducing-antioxidant power (FRAP) and 2,2′-azino-bis spectrophotometric methods (3-ethylbenzthiazoline-6-sulphonic acid) radical cation-scavenging activity (ABTS) additionally determined antioxidant capacity. The FRAP results ranged from 2.9702–9.9418 mmoL Fe/g dw, while the results for ABTS assays expressed as Trolox equivalents (TE) ranged from 14.1842–42.6217 mmoL TE/g dw. The Folin–Ciocalteu procedure was applied to determine the total phenolics content (TP). The TP content expressed as Gallic acid equivalents (GAE) ranged from 6.0343–9.472 mmoL GAE/g dw. The measurements of total flavonoid (TF) and total condensed tannin (TT) contents were also performed to obtain a broader polyphenolic profile of tested plant materials. Origanum vulgare L. scored the highest on each test, with the exception of TT content, followed by the Mentha × piperita L., Artemisia annua L., and Artemisia absinthium L., respectively. The highest TT content, expressed as mg of (−)catechin equivalents per gram of dried weight of sample (mg CE/g dw), was achieved with A. absinthium extract (119.230 mg CE/g dw) followed by O. vulgare (90.384 mg CE/g dw), A. annua (86.538 mg CE/g dw) and M. piperita (69.231 mg CE/g dw), respectively. In addition, a very good correlation between electrochemical and spectroscopic methods was achieved.
The largest mountainous lake in Bosnia and Herzegovina, Lake Blidinje, is located 1,185 meters above sea level. Polymictic lakes are those in which the entire water column is frequently mixed. Shallow lakes function very differently than deep lakes in many ways because of the strong sediment– water interaction and the possibility for significant water impact on vegetation. In the multiple regression analysis, two models were developed with coefficients of multiple determination (R2 = 0.720 and R2 = 0.497) for the independent variable chlorophyll a. The resulting models are compared with water quality monitoring data from 2017 to 2019.
The possibility of determining N-acetyl-L-cysteine or Glutathione based on the reaction with Cu(II)-neocuproine complex according to a simple procedure and using a spectrophotometer or a smartphone as detectors is described. The analytical applicability of the methods was tested and the excellent characteristics of the smartphone as a detector in the analysis of pharmaceuticals were observed. The prepared reaction solutions were yellow and their absorbance was measured at a wavelength of 450 nm. Also, due to the yellow color of the solution, the intensity of the blue RGB channel decreased with increasing thiol concentration. The proposed procedures allow the determination of both thiols in the linear dynamic range from 3.0×10− 6 to 2.0×10− 4 mol L-1 for a spectrophotometer as a detector, or from 6.0×10− 6 to 2.0×10− 4 mol L-1 for a smartphone as a detector. The obtained results indicate the usefulness of the CUPRAC method in the analysis of thiols, but also represent a smartphone as a comparable detector with a UV-Vis spectrophotometer.