New accurate, precise, and sensitive spectrophotometric method were developed for the assay of L-ascorbic acid in pharmaceutical preparations. The determination of L-ascorbic acid was based on its oxidation by potassium peroxydisulfate in the presence of Ag(I) as a catalyst. The molar absorptivity of the proposed method was found to be 8.61 · 103 L mol-1 cm-1 at 248 nm. Beer's law was obeyed in the concentration range of 0.46–20.0 μg mL–1. Other compounds commonly found in vitamin C and multivitamin products did not interfere with the determination of L-ascorbic acid. The proposed method was successfully applied for the determination of L-ascorbic acid in pharmaceutical formulations. The results obtained with the proposed method showed good agreement with those given by the titrimetric method using iodine.

In addition to soda, the Solway production process yields large amounts of waste sludge that contains a high percentage of CaCO3 and Ca(OH)2. In this paper, solid waste sludge from a soda factory in Bosnia and Herzegovina of a certain granulation was used to remove metal ions from the binary system initial concentrations of 500 mg/L. The research results showed that the precipitation efficiency for the binary system Cu - Ni was 99.810% at a pH of 11.42 for Cu2+ and 99.896% for Ni2+ at a pH of 10.86, while for the binary system Pb - Zn it was 99.84% at the same pH value of 10.64. This research has shown that it is very difficult to separate and remove metal precipitation from binary systems because the optimal pH for one metal does not correspond to another metal.

: The hydroxide precipitation method, using NaOH as a precipitant agent, was conducted to treat synthetic monocomponent and two-component water solutions of Pb 2+ and Zn 2+ with initial concentrations of 50 and 500 mg/l of each metal. The effect of pH and initial concentration of lead and zinc ions on their removal were investigated. The precipitation experiments were carried out by batch method that involves the mixing of NaOH with solutions containing metal ions to occur nucleation, solid growth and subsequent separation of precipitates from solution by filtration. The results showed that the removal efficiency was increased by increasing of pH and initial concentration of metal ions in their water solutions. Hydroxide precipitation method using NaOH is an ef-ficient technique for the removal of lead and zinc ions from their monocomponent and two-component water solutions of different concentrations, with maximum removal efficiency in the pH range of 10.32 to 11.39.

Two new, accurate, precise, and sensitive spectrophotometric methods were developed for the assay of L-ascorbic acid in pharmaceutical preparations. The determination of L-ascorbic acid was based on its oxidation by potassium peroxymonosulfate (method A) and hydrogen peroxide in the presence of Cu(II) as a catalyst (method B). The molar absorptivities were found to be 1.48×10 and 1.06×10 L mol cm for methods A and B, respectively. Beer's law was obeyed in the concentration range of 0.65–11.20 μg mL for method A and 0.51–16.00 μg mL for method B. Other compounds commonly found in vitamin C and multivitamin products did not interfere with the determination of L-ascorbic acid.. The proposed methods were successfully applied for the determination of L-ascorbic acid in pharmaceutical formulations. The results obtained with the proposed methods showed good agreement with those given by the titrimetric method using iodine.

Wild onion is a vegetable plant recognizable as food and folk medicine. Its greater application in the food and pharmaceutical industry has found in last decades. In food industry wild onion is mainly used as a spice, while in the pharmaceutical industry it is a common ingredient in dietary supplements. Processing of a fresh wild onion is constantly increasing. Active ingredients of wild onion are: raw vegetable fibers especially cellulose, allium compounds, chlorophyll, flavonoid, quercetin. Wild onion is used in a fresh and processed condition. In most cases it is processed by drying at 40-50 °C for 5 to 10 hours, but also the active ingredients are extracted with various technological processes. Water content in the final product ranges from 6 10% and water activity from 0,17 to 0,21. Total phenolic content was expressed as mg of gallic acid in 100 g of raw material and it was estimated as an average value 561,013. The antioxidant capacity was expressed as EC50 value that represents amount of sample required for the reduction of 50% DPPH free radicals and it was estimated as an average value 6,032. The content of the water was determined by drying. The water activity and color intensity were estimated by using instrumental methods. Antioxidant capacity was estimated by using of DPPH method and phenolic content by application of Folin-Ciocalteu calorimetry. Processing of fresh wild onion in the standardized dried semiproducts may be significant due to the conservation of biological properties, and possibility of applications in the food and pharmaceutical industries. Abbreviations: DPPH-2,2-diphenyl-1-picrylhydrazyl; EC50, concentration of antioxidant needed to reduce the original amount of radical by 50%.

Wheat bread was prepared by replacing 15%, 30% and 40% of white wheat flour with wholegrain buckwheat flour. Total phenols content (Folin–Ciocalteu method) and antioxidant activity (FRAP) of buckwheat flour enriched wheat bread samples and flour mixtures were analysed and compared with wheat bread and wheat flour (control samples). Wholegrain buckwheat flour (17.91 mg GA/L extract) contained higher total phenols than wheat flour (9.11 mg GA/L extract). The incorporation of buckwheat flour in bread samples increased the total phenols content from 7.46 (mg GA/L extract) to 10.13 (mg GA/L extract), and antioxidant activity from 231.45 (µmol Fe 2+ /L extract) to 368.45 (µmol Fe 2+ /L extract). Total phenols content decreased during the baking process, while the antioxidant activity increased. Bread samples with 15%, 30% and 40% of wholegrain buckwheat flour showed lower L values of crust and crumb colour compared to the control sample.