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).

Relation of concentration of metals in soil and plants can present very important indicator of physical – chemical properties of soil and plants, because it could be the base for estimating the level of metal content in plants and contamination, as well as the mobility of ionic metal forms at phases. Experimental work includes metal's intake by vegetables from both contaminated and noncontaminated soil, and determined concentrations are used for calculation of distribution coefficients in soil and plants for some elements such as zinc, cadmium, lead and copper. Experiments have been performed in laboratory conditions and distribution coefficients obtained in this work present indicator of level of plant contamination and physical – chemical changes at equilibrium phases. Obtained results showed that the soil conditions dictate the intake of ionic forms of heavy metals by vegetable root, and the intake is mostly dependent on physical – chemical properties of soil such as pH; CEC; electrical conductivity, and other.

ABSTRACT HACCP system is systematic approach, which is used to prevent hazards appearing through food processing. Although the first step in HACCP system includes identification and analyses of all kinds of hazards, heavy metals present the kind of hazards that are very difficult to determine during identification process. In fact, they are present in small concentrations in all raw materials and food products; therefore, particular attention should be paid to their identification and determination. Regarding above mentioned, this work is aimed to present HACCP application on lead and cadmium in the technological process of cucumbers preserving, where special attention is paid to the content of lead and cadmium. In determined critical control points, CCPs, the content of these metals is determined by the electrochemical method. Based on the results obtained in this work and HACCP system, HACCP plan is given as the instruction for controlling hazards such as heavy metals.