Microplastic, particles less than 5 mm, is an increasing source of pollution in the world, and due its small dimensions it is difficult to analyze and remove it. It is estimated that an average of eight million tons of plastic per year end in the oceans and seas. By the action of waves and sea currents, microplastic that floats in the sea column can reach seaside beaches where it accumulates, and because of flax becomes heavier than water and ends up in sediment. In this paper, 5 types of plastic were tested in 7 different packaging: polyethylene terephthalate (PET), high density polyethylene (HDPE), low density polyethylene (LDPE), polystyrene (PS) and polypropylene (PP). The paper provides an overview of the spectrum, identification of plastic packaging and database creation. This paper confirms the possibility of using a new proposed and described method of separating the microplastic particles from the sediment using sodium polytungstat (SPT). Sodium polytungstat is a heavy liquid used to separate materials of varying densities by their buoyancy, most often when separating heavy minerals. The SPT's properties with respect to the similar fluids used to isolate microplastics is its non-toxicity, which could reduce the negative impact on the environment. The paper proposes and describes the analysis of small particles of microplastic, which can not be recorded by the ATR method because of its dimensions, using KBr tablets. Three out of seven shots did not yield satisfactory results and thus, without further research and modification, this method can not be used for microplastic analysis.