Paper described the method of measuring water content in food products, based on microwave heating and drying of the foodstuff samples. Power supplied to material is controlled as a function of sample mass and features, thus the sample is dried in a short time without overheating. Water content is automatically calculated from the mass losses during drying. The experiments conducted with yoghurt confirmed agreement of the results with a reference method

The issues related to the determination of water content in food products by means of infrared radiation and microwave radiation were discussed in presented work. The advantages and disadvantages of the discussed methods are indicated. In the research part, the accuracy and speed of water content analysis was checked when it is carried out using a moisture analyzer (MA 50.X2.A) based on infrared radiation and when the same products are subject to a moisture analyzer (PMV 50) emitting microwave radiation. The following products: natural yoghurt, milk, vanilla cream cheese, cream cheese with olives and margarine were examined. It was found that the accuracy of the water content analysis in the tested products ranged from 0,01 percent to 0,52 percent when using microwaves and from 0,02 percent to 0,26 percent when the heat source was infrared radiation. The analysis time of the water content was about 3 minutes when using microwavesand about 13 minutes for infrared radiation.

A composite of MCM-41 silica with rice husk was modified with dithizone with the aid of microwave radiation. The modified composite was characterized by different techniques and utilized for preconcentration of Cu²⁺, Zn²⁺ and Pb²⁺ prior to determination by flame atomic absorption spectrometry (FAAS). The adsorption process is optimized to attain the maximum efficiency. The procedure presented satisfying uptake characteristics with maximum adsorption capacity of 142.7, 102.9 and 228.8 mg g⁻¹ towards Cu²⁺, Zn²⁺ and Pb²⁺, respectively. The calibration graphs were linear up to 400 μg L⁻¹ for Cu²⁺ and Zn²⁺ and up to 800 μg L⁻¹ for Pb²⁺ with preconcentration factor of 240. The limits of detection were 0.28, 0.21 and 0.48 μg L⁻¹ for Cu²⁺, Zn²⁺ and Pb²⁺, respectively. The optimized procedure was utilized for the preconcentration of Cu²⁺, Zn²⁺ and Pb²⁺ in water and food samples prior to determination by FAAS with accepted precision and accuracy.