A new, selective and accurate direct ultraviolet spectrophotometric method was developed for the determination of L-ascorbic acid in pharmaceuticals. The oxidation of L-ascorbic acid by iodate in an acidic medium was used as a means of correcting for background absorption. The molar absorptivity of the proposed method was found to be 8.71x103 dm3 mol-1 cm-1 at 250 nm. Beer’s law was obeyed in the concentration range of 0.46 – 16.00 μg cm-3 for L-ascorbic acid. The relative standard deviation was 0.67 % for a concentration of 8.00 μg cm-3 of ascorbic acid (n = 7). The ingredients commonly found in vitamin C and multivitamin products did not interfere. The proposed procedure was successfully applied to assays of L-ascorbic acid in pharmaceutical preparations. The results obtained with the proposed method showed good agreement with those given by the titrimetric method using iodine.

The content of the some ingredients, such as proteins, ash, etc. is important in food products, either they are present in raw materials or in final products. As wheat is also very important food raw material, and flour as the fi nal product of milling, it is important to know their specific physical – chemical properties. The importance of knowing the physical and chemical properties of wheat and flour is due to the determination of quality and kind of fl our which is produced after milling process. In this work, some physical – chemical properties are determined and some comparations of characteristics were performed in both wheat and flour. Characteristics that were observed in this work are moisture content, ash content, protein content, Zeleny sedimentation value, gluten content and water adsorption values. On the base of results obtained in this work, some conclusions are made that could be useful for milling industry.

A simple and highly sensitive direct spectrophotometric method was developed for the determination of L-ascorbic acid. Potassium cyanide (9.21x10-5 mol dm-3) was used to stabilize ascorbic acid in aqueous medium. Th e molar absorptivity of the proposed method, which does not require an extraction procedure, was 1.38x104 dm3 mol-1 cm-1 at 264 nm. Beer’s law was obeyed in the concentration range of 0.26 – 12.0 μg ascorbic acid cm-3. Th e relative standard deviation was 1.40 % for the determination of 8.0 μg ascorbic acid cm-3 (n = 7).