The aim of this work was the qualitative and quantitative determination of selected phenolic compounds in three Crataegus species grown in Bosnia. Crataegus plants are consumed for medicinal purposes and as foodstuff in the form of canned fruit, jam, jelly, tea, and wine. Two samples of plant material, dry leaves with flowers, and berries of three Crataegus species—Crataegus rhipidophylla Gand., Crataegus x subsphaericea Gand., and Crataegus x macrocarpa Hegetschw.—were analyzed. Twelve ethanolic extracts were isolated from the selected plant material using Soxhlet and ultrasound extraction, respectively. Soxhlet extraction proved to be more effective than ultrasound extraction. A simple and sensitive method, high-performance liquid chromatography with electrochemical detection, HPLC-ED, was used for the simultaneous determination of phenolic acids and flavonoids in Crataegus species. The content of gallic acid in the extracts ranged from 0.001 to 0.082 mg/g dry weight (DW), chlorogenic acid from 0.19 to 8.70 mg/g DW, and rutin from 0.03 to 13.49 mg/g DW. Two flavonoids, vitexin and hyperoside, commonly found in chemotaxonomic investigations of Crataegus species, were not detected in the examined extracts. In general, leaves with flowers samples are richer in gallic acid and rutin, whereas the berries samples are richer in chlorogenic acid. Distinct similarities were found in the relative distribution of gallic acid among the three species. Extracts of C. x macrocarpa had the highest content of all detected compounds, while significant differences were found in rutin content, depending on the plant organ. To the best of our knowledge, this is the first study reporting content of phenolic compounds in Crataegus rhipidophylla Gand., Crataegus x subsphaericea, and Crataegus x macrocarpa from Bosnia.

Ascorbic acid (AA) is a water-soluble vitamin which shows no fluorescence. However, in reaction with iron(III), AA is oxidised to dehydroascorbic acid and iron(III) is reduced to iron(II) which forms a complex with 2,4,6-tripyridyl-S-triazine (TPTZ) in buffered medium. The relative fluorescence intensity of the resulting Fe(TPTZ)₂²⁺ complex can be measured at excitation and emission wavelengths of 393 and 790 nm, respectively. Based on this data, a new indirect spectrofluorimetric method for the determination of AA in pharmaceutical samples was proposed. Influence of the reaction conditions, such as acidity of acetic buffer, concentration of TPTZ and iron(III), reaction time and instrumental parameters were investigated in detail. The linear range was from 5.4 × 10⁻⁴ to 5.4 × 10⁻⁶ mol·L⁻¹ (R = 0.9971). The LOD was 7.7 × 10⁻⁷ mol·L⁻¹ and LOQ was 2.3 × 10⁻⁴ mol·L⁻¹. Fourteen pharmaceutical samples containing various amounts of AA were analysed. Influences of potential interfering substances were also examined. Analysis of commercial pharmaceutical formulations showed good correlation with the nominal values given by the manufacturers and with the results obtained by a titration method. The proposed method can be applied in routine quality control in the pharmaceutical industry due to its sensitivity, simplicity, selectivity and low cost.

Based on the interaction between ascorbic acid and bromocresol purple, a new simple, straightforward, and quick method for the quantification of ascorbic acid is proposed. The procedure is based on the determined quenching effect of ascorbic acid on the natural fluorescence signal of bromocresol purple in the reaction between ascorbic acid and bromocresol purple in phosphate buffer solution (pH 6). The reduction of bromocresol purple fluorescence intensity is detected at 641 nm, while excitation occurs at 318 nm. The linear relationship between the reduced fluorescence intensity of bromocresol purple and the concentration of ascorbic acid is in the range 4.65 × 10^–5 to 4.65 × 10^–6 mol L⁻¹ (R² = 0.9964), with the detection limit of 8.77 × 10^–7 mol L⁻¹ and quantification limit of 2.35 × 10^–5 mol L⁻¹. The findings in this study further show that the new method provides good precision and repeatability, as well as satisfactory recovery values in terms of accuracy. The new method is tested on fifteen samples with different amounts of ascorbic acid and additional components. The effects of interfering components such as citrus bioflavonoids, citric acid, folic acid, paracetamol, calcium, and magnesium carbonate on the intensity of fluorescence of bromocresol purple are also investigated. The effects of interfering components such as citrus bioflavonoids (routine and hesperidin), citric acid, folic acid, paracetamol, calcium, and magnesium carbonate on the intensity of fluorescence of bromocresol purple are also investigated. The results of iodometric titration point out that the new method is effective for the determination of ascorbic acid in pharmaceutical samples. Article Highlights: A new spectrofluorimetric method for determination of ascorbic acid in pharmaceutical samples using bromocresol purple. Determination of optimal parameters for ascorbic acid determination in a variety of pharmaceutical samples. Examination of the influence of additional substances in the pharmaceutical samples on the analysis.

Pyrophyllite was investigated in this study as a potential adsorbent for the removal of glyphosate, a common herbicide for the control of a wide variety of weeds. There are several publications in the literature that discuss how glyphosate interacts with clay minerals such as montmorillonite, kaolinite, and bentonite, but there is no information regarding the possibility of glyphosate removal from aqueous solution using pyrophyllite. In this study, the adsorption of glyphosate from water samples onto pyrophyllite, a mineral clay from the Parsovici, Konjic mine, was investigated. The ninhydrin reaction was used to spectrophotometrically quantify glyphosate. At 570 nm, the purple Ruhemman product's absorbance was determined. Adsorption capacity (qe), removal efficiency (R), and the partition coefficient are used to express the results (Kd). The outcomes demonstrated that distinct ionic species of glyphosate at different pHs cause the adsorption of glyphosate on pyrophyllite to be pH-dependent. The findings demonstrated that during different contact times, the basic medium can remove up to 75% of glyphosate. According to results from fitting isotherm models, the Freundlich model is slightly better fitted. According to the results of kinetic investigations, the pseudo-2nd order model is more suitable for this kind of adsorption.